interest rates – Page 4

Alvin Hansen on Monetary Policy

The more you read in the history of macroeconomics and monetary theory, the more you find that current debates are reprises of arguments from 50, 100 or 200 years ago.

I’ve just been reading Perry Mehrling’s The Money Interest and the Public Interest, which is one of the two best books I know of on this subject. (The other is Arie Arnon’s Monetary Theory and Policy Since David Hume and Adam Smith.) About a third of the book is devoted to Alvin Hansen, and it inspired me to look up some of Hansen’s writings from the 1940s and 50s. I was especially struck by this 1955 article on monetary policy. It not only anticipates much of current discussions of monetary policy — quantitative easing, the maturity structure of public debt, the need for coordination between the fiscal and monetary policy, and more broadly, the limits of a single interest rate instrument as a tool of macroeconomic management — but mostly takes them for granted as starting points for its analysis. It’s hard not to feel that macro policy debates have regressed over the past 60 years.

The context of the argument is the Treasury-Federal Reserve Accord of 1951, following which the Fed was no longer committed to maintaining fixed rates on treasury bonds of various maturities. [1] The freeing of the Fed from the overriding responsibility of stabilizing the market for government debt, led to scholarly and political debates about the new role for monetary policy. In this article, Hansen is responding to several years of legislative debate on this question, most recently the 1954 Senate hearings which included testimony from the Treasury department, the Fed Board’s Open Market Committee, and the New York Fed.

Hansen begins by expressing relief that none of the testimony raised

the phony question whether or not the government securities market is “free.” A central bank cannot perform its functions without powerfully affecting the prices of government securities.

He then expresses what he sees as the consensus view that it is the quantity of credit that is the main object of monetary policy, as opposed to either the quantity of money (a non-issue) or the price of credit (a real but secondary issue), that is, the interest rate.

Perhaps we could all agree that (however important other issues may be) control of the credit base is the gist of monetary management. Wise management, as I see it, should ensure adequate liquidity in the usual case, and moderate monetary restraint (employed in conjunction with other more powerful measures) when needed to check inflation. No doubt others, who see no danger in rather violent fluctuations in interest rates (entailing also violent fluctuations in capital values), would put it differently. But at any rate there is agreement, I take it, that the central bank should create a generous dose of liquidity when resources are not fully employed. From this standpoint the volume of reserves is of primary importance.

Given that the interest rate is alsoan object of policy, the question becomes, which interest rate?

The question has to be raised: where should the central bank enter the market -short-term only, or all along the gamut of maturities?

I don’t believe this is a question that economists asked much in the decades before the Great Recession. In most macro models I’m familiar with, there is simply “the interest rate,” with the implicit assumption that the whole rate structure moves together so it doesn’t matter which specific rate the monetary authority targets. For Hansen, by contrast, the structure of interest rates — the term and “risk” premiums — is just as natural an object for policy as the overall level of rates. And since there is no assumption that the whole structure moves together, it makes a difference which particular rate(s) the central bank targets. What’s even more striking is that Hansen not only believes that it matters which rate the central bank targets, he is taking part in a conversation where this belief is shared on all sides.

Obviously it would make little difference what maturities were purchased or sold if any change in the volume of reserve money influenced merely the level of interest rates, leaving the internal structure of rates unaffected. … In the controversy here under discussion, the Board leans toward the view that … new impulses in the short market transmit themselves rapidly to the longer maturities. The New York Reserve Bank officials, on the contrary, lean toward the view that the lags are important. If there were no lags whatever, it would make no difference what maturities were dealt in. But of course the Board does not hold that there are no lags.

Not even the most conservative pole of the 1950s debate goes as far as today’s New Keynesian orthodoxy that monetary policy can be safely reduced to the setting of a single overnight interest rate.

The direct targeting of long rates is the essential innovation of so-called quantitative easing. [2] But to Hansen, the idea that interest rate policy should directly target long as well as short rates was obvious. More than that: As Hansen points out, the same point was made by Keynes 20 years earlier.

If the central bank limits itself to the short market, and if the lags are serious, the mere creation of large reserves may not lower the long-term rate. Keynes had this in mind when he wrote: “Perhaps a complex offer by the central bank to buy and sell at stated prices gilt-edged bonds of all maturities, in place of the single bank rate for short-term bills, is the most important practical improvement that can be made in the technique of monetary management. . . . The monetary authority often tends in practice to concentrate upon short-term debts and to leave the price of long-term debts to be influenced by belated and imperfect re- actions from the price of short-term debts.” ‘ Keynes, it should be added, wanted the central bank to deal not only in debts of all maturities, but also “to deal in debts of varying degrees of risk,” i.e., high grade private securities and perhaps state and local issues.

That’s a quote from The General Theory, with Hansen’s gloss.

Fast-forward to 2014. Today we find Benjamin Friedman — one of the smartest and most interesting orthodox economists on these issues — arguing that the one great change in central bank practices in the wake of the Great Recession is intervention in a range of securities beyond the shortest-term government debt. As far as I can tell, he has no idea that this “profound” innovation in the practice of monetary policy was already proposed by Keynes in 1936. But then, as Friedman rightly notes, “Macroeconomics is a field in which theory lags behind experience and practice, not the other way around.”

Even more interesting, the importance of the rate structure as a tool of macroeconomic policy was recognized not only by the Federal Reserve, but by the Treasury in its management of debt issues. Hansen continues:

Monetary policy can operate on two planes: (1) controlling the credit base – the volume of reserve balances- and (2) changing the interest rate structure. The Federal Reserve has now backed away from the second. The Treasury emphasized in these hearings that this is its special bailiwick. It supports, so it asserts, the System’s lead, by issuing short- terms or long-terms, as the case may be, according to whether the Federal Reserve is trying to expand or contract credit … it appears that we now have (whether by accident or design) a division of monetary management between the two agencies- a sort of informal cartel arrangement. The Federal Reserve limits itself to control of the volume of credit by operating exclusively in the short end of the market. The Treasury shifts from short-term to long-term issues when monetary restraint is called for, and back to short-term issues when expansion is desired.

This is amazing. It’s not that Keynesians like Hansen propose that Treasury should issue longer or shorter debt based on macroeconomic conditions. Rather, it is taken for granted that it does choose maturities this way. And this is the conservative side in the debate, opposed to the side that says the central bank should manage the term structure directly.

Many Slackwire readers will have recently encountered the idea that the maturities of new debt should be evaluated as a kind of monetary policy. It’s on offer as the latest evidence for the genius of Larry Summers. Proposing that Treasury should issue short or long term debt based on goals for the overall term structure of interest rates, and not just on minimizing federal borrowing costs, is the main point of Summers’ new Brookings paper, which has attracted its fair share of attention in the business press. No reader of that paper would guess that its big new idea was a commonplace of policy debates in the 1950s. [3]

Hansen goes on to raise some highly prescient concerns about the exaggerated claims being made for narrow monetary policy.

The Reserve authorities are far too eager to claim undue credit for the stability of prices which we have enjoyed since 1951. The position taken by the Board is not without danger, since Congress might well draw the conclusion that if monetary policy is indeed as powerful as indicated, nonmonetary measures [i.e. fiscal policy and price controls] are either unnecessary or may be drawn upon lightly.

This is indeed the conclusion that was drawn, more comprehensively than Hansen feared. The idea that setting an overnight interest rate is always sufficient to hold demand at the desired level has conquered the economics profession “as completely as the Holy Inquisition conquered Spain,” to coin a phrase. If you talk to a smart young macroeconomist today, you’ll find that the terms “aggregate demand was too low” and “the central bank set the interest rate too high” are used interchangeably. And if you ask, which interest rate?, they react the way a physicist might if you asked, the mass of which electron?

Faced with the argument that the inflation of the late 1940s, and price stability of the early 1950s, was due to bad and good interest rate policy respectively, Hansen offers an alternative view:

I am especially unhappy about the impli- cation that the price stability which we have enjoyed since February-March 1951 (and which everyone is justifiably happy about) could quite easily have been purchased for the entire postwar period (1945 to the present) had we only adopted the famous accord earlier … The postwar cut in individual taxes and the removal of price, wage, and other controls in 1946 … did away once and for all with any really effective restraint on consumers. Under these circumstances the prevention of price inflation … [meant] restraint on investment. … Is it really credible that a drastic curtailment of investment would have been tolerated any more than the continuation of wartime taxation and controls? … In the final analysis, of course, the then prevailing excess of demand was confronted with a limited supply of productive resources.

Inflation always comes down to this mismatch between “demand,” i.e. desired expenditure, and productive capacity.

Now we might say in response to such mismatches: Well, attempts to purchase more than we can produce will encourage increased capacity, and inflation is just a temporary transitional cost. Alternatively, we might seek to limit spending in various ways. In this second case, there is no difference of principle between an engineered rise in the interest rate, and direct controls on prices or spending. It is just a question of which particular categories of spending you want to hold down.

The point: Eighty years ago, Keynes suggested that what today is called quantitative easing should be a routine tool of monetary policy. Sixty years ago, Alvin Hansen believed that this insight had been accepted by all sides in macroeconomic debates, and that the importance of the term structure for macroeconomic activity guided the debt-issuance policies of Treasury as well as the market interventions of the Federal Reserve. Today, these seem like new discoveries. As the man says, the history of macroeconomics is mostly a great forgetting.

[1] I was surprised by how minimal the Wikipedia entry is. One of these days, I am going to start having students improve economics Wikipedia pages as a class assignment.

[2] What is “quantitative about this policy is that the Fed buys a a quantity of bonds, evidently in the hopes of forcing their price up, but does not announce an explicit target for the price. On the face of it, this is a strangely inefficient way to go about things. If the Fed announced a target for, say, 10-year Treasury bonds, it would have to buy far fewer of them — maybe none — since market expectations would do more of the work of moving the price. Why the Fed has hobbled itself in this way is a topic for another post.

[3] I am not the world’s biggest Larry Summers fan, to say the least. But I worry I’m giving him too hard a time in this case. Even if the argument of the paper is less original than its made out to be, it’s still correct, it’s still important, and it’s still missing from today’s policy debates. He and his coauthors have made a real contribution here. I also appreciate the Hansenian spirit in which Summers derides his opponents as “central bank independence freaks.”

The Rentier Would Prefer Not to Be Euthanized

Here’s another one for the “John Bull can stand many things, but he cannot stand two percent” files. As Krugman says, there’s an endless series of these arguments that interest rates must rise. The premises are adjusted as needed to reach the conclusion. (Here’s another.) But what are the politics behind it?

I think it may be as simple as this: The rentiers would prefer not to be euthanized. Under capitalism, the elite are those who own (or control) money. Their function is, in a broad sense, to provide liquidity. To the extent that pure money-holders facilitate production, it is because money serves as a coordination mechanism, bridging gaps — over time and especially with unknown or untrusted counterparties — that would otherwise prevent cooperation from taking place. [1] In a world where liquidity is abundant, this coordination function is evidently obsolete and can no longer be a source of authority or material rewards.

More concretely: It may well be true that markets for, say, mortgage-backed securities are more likely to behave erratically when interest rates are very low. But in a world of low interest rates, what function do those markets serve? Their supposed purpose is to make it easier for people to get home loans. But in a world of very low interest rates, loans are, by definition, easy to get. Again, with abundant liquidity, stocks may get bubbly. But in a world of abundant liquidity, what problem is the existence of stock markets solving? If anyone with a calling to run a business can readily start one with a loan, why support a special group of business owners? Yes, in a world where bearing risk is cheap, specialist risk-bearers are likely to go a bit nuts. But if risk is already cheap, why are we employing all these specialists?

The problem is, the liquidity specialists don’t want to go away. From finance’s point of view, permanently low interest rates are removing their economic reason for being — which they know eventually is likely to remove their power and privileges too. So we get all these arguments that boil down to: Money must be kept scarce so that the private money-sellers can stay in business.

It’s a bit like Dr. Benway in Naked Lunch:

“Now, boys, you won’t see this operation performed very often and there’s a reason for that…. You see it has absolutely no medical value. No one knows what the purpose of it originally was or if it had a purpose at all. Personally I think it was a pure artistic creation from the beginning.

“Just as a bull fighter with his skill and knowledge extricates himself from danger he has himself invoked, so in this operation the surgeon deliberately endangers his patient, and then, with incredible speed and celerity, rescues him from death at the last possible split second….

Interestingly, Dr. Benway was worried about technological obsolescence too. “Soon we’ll be operating by remote control on patients we never see…. We’ll be nothing but button pushers,” etc. The Dr. Benways of finance like to fret about how robots will replace human labor. I wonder how much of that is a way of hiding from the knowledge that what cheap and abundant capital renders obsolete, is the capitalist?

EDIT: I’m really liking the idea of Larry Summers as Dr. Benway. It fits the way all the talk when he was being pushed for Fed chair was about how great he would be in a financial crisis. How would everyone known how smart he was — how essential — if he hadn’t done so much to create a crisis to solve?

[1] Capital’s historic role as a facilitator of cooperation is clearly described in chapter 13 of Capital.

Boulding on Interest

Kenneth Boulding, reviewing Maurice Allais’s Économie et intérêt in 1951:

Much work on the theory of interest is hampered at the start by its unquestioned assumption that “the” rate of interest, or even some complex of rates, is a suitable parameter for use in the construction of systems of economic relationships, whether static or dynamic. This is an assumption which is almost universally accepted and yet which seems to me to be very much open to question. My reason for questioning it is that the rate of interest is not an objective magnitude… The rate of interest is not a “price”; its dimensions are those of a rate of growth, not of a ratio of exchange, even though it is sometimes carelessly spoken of as a “price of loanable funds.” What is determined in the market is not strictly the rate of interest but the price of certain “property rights.” These may be securities, either stocks or bonds, or they may be items or collections of physical property. Each of these property rights represents to an individual an expected series of future values, which may be both positive and negative. If this expected series of values can be given some “certainty equivalent” … then the market price of the property determines a rate of interest on the investment. This rate of interest, however, is essentially subjective and depends on the expectations of the individual; the objective phenomenon is the present market price…

It is only the fact that the fulfilment of some expectations seems practically certain that gives us the illusion that there is an objective rate of interest determined in the market. But in strict theory there is no such certainty, even for gilt-edged bonds; and when the uncertainties of life, inflation, and government are taken into consideration, it is evident that this theoretical uncertainty is also a matter of practice. What is more, we cannot assume either that there are any “certain equivalents” of uncertain series for it is the very uncertainty of the future which constitutes its special quality. What this means is that it is quite illegitimate even to begin an interest theory by abstracting from uncertainty or by assuming that this can be taken care of by some “risk premium”; still less is it legitimate to construct a whole theory on these assumptions … without any discussion of the problems which uncertainty creates. What principally governs the desired structure of assets on the part of the individual is the perpetual necessity to hedge — against inflation, against deflation, against the uncertainty in the future of all assets, money included. It is these uncertainties, therefore, which are the principal governors of the demand and supply of all assets without exception, and no theory which abstracts from these uncertainties can claim much significance for economics. Hence, Allais is attempting to do something which simply cannot be done, because it is meaningless to construct a theory of “pure” interest devoid of premiums for risk, liquidity, convenience, amortization, prestige, etc. There is simply no such animal.

In other words: There are contexts when it is reasonable to abstract from uncertainty, and proceed on the basis that people know what will happen in the future, or at least its probability distribution. But interest rates are not such a context, you can’t abstract away from uncertainty there. Because compensation for uncertainty is precisely why interest is paid.

The point that what is set in the market, and what we observe, is never an interest rate as such, but the price of some asset today in terms of money today, is also important.

Boulding continues:

The observed facts are the prices of assets of all kinds. From these prices we may deduce the existence of purely private rates of return. The concept of a historical “yield” also has some validity. But none of these things is a “rate of interest” in the sense of something determined in a market mechanism.

This search for a black cat that isn’t there leads Allais into several extended discussions of almost meaningless and self-constructed questions… Thus he is much worried about the “fact” that a zero rate of interest means an infinite value for land, land representing a perpetual income, which capitalized at a zero rate of interest yields an infinite value… This is a delightful example of the way in which mathematics can lead to an almost total blindness to economic reality. In fact, the income from land is no more perpetual than that from anything else and no more certain. … We might draw a conclusion from this that a really effective zero rate of interest in a world of perfect foresight would lead to an infinite inflation; but, then, perfect foresight would reduce the period of money turnover to zero anyway and would give us an infinite price level willy-nilly! This conclusion is interesting for the light it throws on the complete uselessness of the “perfect foresight” model but for little else. In fact, of course, the element which prevents both prices from rising to infinity and (private) money rates of interest from falling to zero is uncertainty – precisely the factor which Allais has abstracted from. Another of these quite unreal problems which worries him a great deal is why there is always a positive real rate of interest, the answer being of course that there isn’t! …

Allais reflects also another weakness of “pure”interest theory, which is a failure to appreciate the true significance and function of financial institutions and of “interest” as opposed to “profit” – interest in this sense being the rate of growth of value in “securities,” especially bonds, and “profit” being the rate of growth of value of items or combinations of real capital. Even if there were no financial institutions or financial instruments … there would be subjective expected rates of profit and historical yields on past, completed investments. In such a society, however, given the institution of private property, everyone would have to administer his own property. The main purpose of the financial system is to separate “ownership” (i.e., equity) from “control,” or administration, that is, to enable some people to own assets which they do not control, and others to control assets which they do not own. This arrangement is necessitated because there is very little, in the processes by which ownership was historically determined through inheritance and saving, to insure that those who own the resources of society are … capable of administering them. Interest, in the sense of an income received by the owners of securities, is the price which society pays for correcting a defect in the otherwise fruitful institution of private property. It is, of course, desirable that the price should be as small as possible – that is, that there should be as little economic surplus as possible paid to nonadministering owners. It is quite possible, however, that this “service” has a positive supply price in the long run, and thus that, even in the stationary state, interest, as distinct from profit, is necessary to persuade the nonadministering owners to yield up the administration of their capital.

This last point is important, too. Property, we must always remember, is not a relationship between people and things. it is a relationship between people and people. Ownership of an asset means the authority to forbid other people from engaging in a certain set of productive activities. The “product” of the asset is how much other people will pay you not to exercise that right. Historically, of course, the sets of activities associated with a given asset have often been defined in relation to some particular means of production. But this need not be the case. In a sense, the patent or copyright isn’t an extension of the idea of property, but property in its pure form. And even where the rights of an asset owner are defined as those connected with some tangible object, the nature of the connection still has to be specified by convention and law.

According to Wikipedia, Économie et intérêt, published in 1947, introduced a number of major ideas in macroeconomics a decade or more before the American economists they’re usually associated with, including the overlapping generations model and the golden rule for growth. Boulding apparently did not find these contributions worth mentioning. He does, though, have something to say about Allais’s “economic philosophy” which “is a curious combination of Geseel, Henry George and Hayek,” involving “free markets, with plenty of trust- and union-busting, depreciating currency, and 100 per cent reserves in the banking system, plus the appropriation of all scarcity rents and the nationalization of land.” Boulding describes this as “weird enough to hit the jackpot.” It doesn’t seem that weird to me. It sounds like a typical example of a political vision you can trace back to Proudhon and forward through the “Chicago plan” of the 1930s and its contemporary admirers to the various market socialisms and more or less crankish monetary reform plans. (Even Hyman Minsky was drawn to this strain of politics, according to Perry Mehrling’s superb biographical essay.)What all these have in common is that they see the obvious inconsistency between capitalism as we observe it around us and the fairy tales of ideal market exchange, but they don’t reject the ideal. Instead, they propose a program of intrusive regulations to compel people to behave as they are supposed to in an unregulated market. They want to make the fairy tales true by legislation. Allais’ proposal for currency depreciation is not normally part of this package; it’s presumably a response to late-1940s conditions in France. But other than that these market utopias are fairly consistent. In particular, it’s always essential to reestablish the objectivity of money.

Finally, in a review full of good lines, I particularly like this one:

Allais’s work is another demonstration that mathematics and economics, though good complements, are very imperfect substitutes. Mathematics can manipulate parameters once formulated and draw conclusions out which were already implicit in the assumptions. But skills of the mathematician are no substitute for the proper skill of the economist, which is that of selecting the most significant parameters to go into the system.

Where Do Interest Rates Come From?

What determines the level of interest rates? It seems like a simple question, but I don’t think economics — orthodox or heterodox — has an adequate answer.

One problem is that there are many different interest rates. So we have two questions: What determines the overall level of interest rates, and what determines the spreads between different interest rates? The latter in turn we can divide into the question of differences in rates between otherwise similar loans of different lengths (term spreads), differences in rates between otherwise similar loans denominated in different currencies, and all the remaining differences, grouped together under the possibly misleading name risk spreads.

In any case, economic theory offers various answers:

1. The orthodox answer, going back to the 18th century, is that the interest rate is a price that equates the desire to save with the desire to borrow. As reformulated in the later 19th century by Bohm-Bawerk, Cassel, etc., that means: The interest rate is the price of goods today relative to goods tomorrow. The interest rate is the price that balances the gains from deferring consumption with our willingness to do so. People generally prefer consumption today to consumption in the future, and because it will be possible to produce more in the future than today, so the interest rate is (normally) positive. This is a theory of all transactions that exchange spending in one period for spending (or income) in another, not specifically a theory of the interest rate on loans.

The Wicksell variant of this, which is today’s central-bank orthodoxy, is that there is a well-defined natural interest rate in this sense but that for some reason markets get this one price wrong.

2. An equally old idea is that the interest rate is the price of money. In Hume’s writings on money and interest, for instance, he vacillates between this and the previous story. It’s not a popular view in the economics profession but it’s well-represented in the business world and among populists and monetary reformers,. In this view, money is just another input to the production process, and the interest rate is its price. A creditor, in this view, isn’t someone deferring consumption to the future, but someone who — like a landlord — receives an income thanks to control of a necessary component of the production process. A business, let’s say, that needs to maintain a certain amount of working capital in the form of money or similarly liquid assets, may need to finance it with a loan on which it pays interest. Interest payments are in effect the rental price of money, set by supply and demand like anything else. As I say, this has never been a respectable view in economic theory, but you can find it in more empirical work, like this paper by Gabriel Chodorow-Reich, where credit is described in exactly these terms as an input to current production.

3. Keynes’ liquidity-preference story in The General Theory. Here again the interest rate is the price of money. But now instead of asking how much the marginal business borrower will pay for the use of money, we ask how much the marginal wealth owner needs to be compensated to give up the liquidity of money for a less-liquid bond. The other side of the market is given by a fixed stock of bonds; evidently we are dealing with a short enough period that the flow of new borrowing can be ignored, and the bond stock treated as exogenously fixed. With no new borrowing, the link from the interest rate is liked to the real economy because it is used to discount the expected flow of profits from new investment — not by business owners themselves, but by the stock market. It’s an oddly convoluted story.

4. A more general liquidity-preference story. Jorg Bibow, in a couple of his essential articles on the Keynesian theory of liquidity preference, suggests that many of the odd features of the theory are due to Keynes’ decision to drop the sophisticated analysis of the financial system from The Treatise on Money and replace it with an assumption of an exogenously fixed money stock. (It’s striking that banks play no role in in the General Theory.) But I’m not sure how much simpler this “simplification” actually makes the story, or whether it is even logically coherent; and in any case it’s clearly inapplicable to our modern world of bank-created credit money. In principle, it should be possible to tell a more general version of the liquidity preference story, where, instead of wealth holders balancing the income from holding a bond against the liquidity from holding “money,” you have banks balancing net income against incremental illiquidity from simultaneously extending a loan and creating a deposit. I’m afraid to say I haven’t read the Treatise, so I don’t know how much you can find that story there. In any case it doesn’t seem to have been developed systematically in later theories of endogenous money, which typically assume that the supply of credit is infinitely elastic except insofar as it’s limited by regulation.

5. The interest rate is set by the central bank. This is the orthodox story when we turn to the macro textbook. It’s also the story in most heterodox writers. From Wicksell onward, the whole discussion about interest rates in a macroeconomic context is about how the central bank can keep the interest rate at the level that keeps current expenditure at the appropriate level, and what happens if it fails to do so. It is sometimes suggested that the optimal or “natural” interest rate chosen by the central bank should be the the Walrasian intertemporal exchange rate — explicitly by Hayek, Friedman and sometimes by New Keynesians like Michael Woodford, and more cautiously by Wicksell. But the question of how the central bank sets the interest rate tends to drop out of view. Formally, Woodford has the central bank set the interest rate by giving it a monopoly on lending and borrowing. This hardly describes real economies, of course, but Woodford insists that it doesn’t matter since central banks could control the interest rate by standing ready to lend or borrow unlimited amounts at thresholds just above and below their target. The quite different procedures followed by real central banks are irrelevant. [1]

A variation of this (call it 5a) is where reserve requirements bind and the central bank sets the total quantity of bank credit or money. (In a world of bind reserve requirements, these will be equivalent.) In this case, the long rate is set by the demand for credit, given the policy-determined quantity. The interbank rate is then presumably bid up to the minimum spread banks are willing to lend at. In this setting causality runs from long rates to short rates, and short rates don’t really matter.

6. The interest rate is set by convention. This is Keynes’ other theory of the interest rate, also introduced in the General Theory but more fully developed in his 1937 article “Alternative Theories of the Rate of Interest.” The idea here is that changes in interest rates imply inverse changes in the price of outstanding bonds. So from the lenders’ point of view, the expected return on a loan includes not only the yield (as adjusted for default risk), but also the capital gain or loss that will result if interest rates change while the loan is still on their books. The longer the term of the loan, the larger these capital gains or losses will be. I’ve discussed this on the blog before and may come back to it in the future, but the essential point is that if people are very confident about the future value of long rates (or at least that they will not fall below some floor) then the current rate cannot get very far from that future expected rate, no matter what short rates are doing, because as the current long rate moves away from the expected long rate expected capital gains come to dominate the current yield. Take the extreme case of a perpetuity where market participants are sure that the rate will be 5% a year from now. Suppose the short rate is initially 5% also, and falls to 0. Then the rate on the perpetuity will fall to just under 4.8% and no lower, because at that rate the nearly 5% spread over the short rate just compensates market participants for the capital loss they expect when long rates return to their normal level. (Obviously, this is not consistent with rational expectations.) These kinds of self-stabilizing conventional expectations are the reason why, as Bibow puts it, “a liquidity trap … may arise at any level of interest.” A liquidity trap is an anti-bubble, if you like.

What do we think about these different stories?

I’m confident that the first story is wrong. There is no useful sense in which the interest rate on debt contracts — either as set by markets or as target by the central bank — is the price of goods today in terms of goods tomorrow. The attempt to understand interest rates in terms of the allocation across time of scarce means to alternative ends is a dead end. Some other intellectual baggage that should overboard with the “natural” rate of interest are the “real”rate of interest, the idea of consumption loans, and the intertemporal budget constraint.

But negative criticism of orthodoxy is too easy. The real work is to make a positive case for an alternative. I don’t see a satisfactory one here.

The second and third stories depend on the existence of “money” as a distinct asset with a measurable, exogenously fixed quantity. This might be a usable assumption in some historical contexts — or it might not — but it clearly does not describe modern financial systems. Woodford is right about that.

The fifth story is clearly right with respect short rates, or at least it was until recently. But it’s incomplete. As an empirical matter, it is true that interbank rates and similar short market rates closely follow the policy rate. The question is, why? The usual answer is that the central bank is the monopoly supplier of base money, and base money is used for settlement between banks. This may be so, but it doesn’t have to be. Plenty of financial systems have existed without central banks, and banks still managed to make payments to each other somehow. And where central banks exist, they don’t always have a monopoly on interbank settlement. During the 19th century, the primary tool of monetary policy at the Bank of England was the discount rate — the discount off of face value that the bank would pay for eligible securities (usually trade credit). But if the discount rate was too high — if the bank offered too little cash for securities — private banks would stop discounting securities at the central bank, and instead find some other bank that was willing to give them cash on more favorable terms. This was the problem of “making bank rate effective,” and it was a serious concern for 19th century central banks. If they tried to raise interest rates too high, they would “lose contact with the market” as banks simply went elsewhere for liquidity.

Obviously, this isn’t a problem today — when the Fed last raised policy rates in the mid-2000s, short market rates rose right along with it. Or more dramatically, Brazil’s central bank held nominal interest rates around 20 percent for nearly a decade, while inflation averaged around 8 percent. [2] In cases like these, the central bank evidently is able to keep short rates high by limiting the supply of reserves. But why in that case doesn’t the financial system develop private substitutes for reserves? Mervyn King blandly dismisses this question by saying that “it does not matter in principle whether the disequilibrium in the money market is an aggregate net shortage or a net surplus of funds—control of prices or quantities carries across irrespective of whether the central bank is the monopoly supplier or demander of its own liabilities.” [3] Clearly, the central bank cannot be both the monopoly supplier and the monopoly demander of reserves, at least not if it wants to have any effect on the rest of the world. The relevant question — to which King offers no answer — is why there are no private substitutes for central bank reserves. Is it simply a matter of legal restrictions on interbank settlements using any other asset? But then why has this one regulatory barrier remained impassable while banks have tunneled through so many others? Anyway, going forward the question may be moot if reserves remain abundant, as they will if the Fed does not shrink its balance sheet back to pre-crisis levels. In that case, new tools will be required to make the policy rate effective.

The sixth story is the one I’m most certain of. First, because it can be stated precisely in terms of asset market equilibrium. Second, because it is consistent with what we see historically. Long term interest rates are quite stable over very long periods. Third, it’s consistent with what market participants say: It’s easy to find bond market participants saying that some rate is “too low” and won’t continue, regardless of what the Fed might think. Last, but not least from my point of view, this view is clearly articulated by Keynes and by Post Keynesians like Bibow. But while I feel sure this is part of the story, it can’t be the whole story. First, because even if a conventional level of interest rates is self-stabilizing in the long run, there are clearly forces of supply and demand in credit markets that push long rates away from this level in the short run. This is even more true if what convention sets is less a level of interest rates, than a floor. And second, because Keynes also says clearly that conventions can change, and in particular that a central bank that holds short rates outside the range bond markets consider reasonable for long enough, will be able to change the definition of reasonable. So that brings us back to the question of how it is that central banks are able to set short rates.

I think the fundamental answer lies behind door number 4. I think there should be a way of describing interest rates as the price of liquidity, where liquidity refers to the capacity to honor one’s promises, and not just to some particular asset. In this sense, the scarce resource that interest is pricing is trust. And monetary policy then is at root indistinguishable from the lender of last resort function — both are aspects of the central bank’s role of standing in as guarantor for commitments within the financial system. You can find elements of this view in the Keynesian literature, and in earlier writers going back to Thornton 200-plus years ago. But I haven’t seen it stated systematically in way that I find satisfactory.

UPDATE: For some reason I brought up the idea of the interest rate as the price of money without mentioning the classic statement of this view by Walter Bagehot. Bagehot uses the term “price of money” or “value of money” interchangeably with “discount rate” as synonyms for the interest rate. The discussion in chapter 5 of Lombard Street is worth quoting at length:

Many persons believe that the Bank of England has some peculiar power of fixing the value of money. They see that the Bank of England varies its minimum rate of discount from time to time, and that, more or less, all other banks follow its lead, and charge much as it charges; and they are puzzled why this should be. ‘Money,’ as economists teach, ‘is a commodity, and only a commodity;’ why then, it is asked, is its value fixed in so odd a way, and not the way in which the value of all other commodities is fixed?

There is at bottom, however, no difficulty in the matter. The value of money is settled, like that of all other commodities, by supply and demand… A very considerable holder of an article may, for a time, vitally affect its value if he lay down the minimum price which he will take, and obstinately adhere to it. This is the way in which the value of money in Lombard Street is settled. The Bank of England used to be a predominant, and is still a most important, dealer in money. It lays down the least price at which alone it will dispose of its stock, and this, for the most part, enables other dealers to obtain that price, or something near it. …

There is, therefore, no ground for believing, as is so common, that the value of money is settled by different causes than those which affect the value of other commodities, or that the Bank of England has any despotism in that matter. It has the power of a large holder of money, and no more. Even formerly, when its monetary powers were greater and its rivals weaker, it had no absolute control. It was simply a large corporate dealer, making bids and much influencing—though in no sense compelling—other dealers thereby.

But though the value of money is not settled in an exceptional way, there is nevertheless a peculiarity about it, as there is about many articles. It is a commodity subject to great fluctuations of value, and those fluctuations are easily produced by a slight excess or a slight deficiency of quantity. Up to a certain point money is a necessity. If a merchant has acceptances to meet to-morrow, money he must and will find today at some price or other. And it is this urgent need of the whole body of merchants which runs up the value of money so wildly and to such a height in a great panic….

If money were all held by the owners of it, or by banks which did not pay an interest for it, the value of money might not fall so fast. … The possessors would be under no necessity to employ it all; they might employ part at a high rate rather than all at a low rate. But in Lombard Street money is very largely held by those who do pay an interest for it, and such persons must employ it all, or almost all, for they have much to pay out with one hand, and unless they receive much with the other they will be ruined. Such persons do not so much care what is the rate of interest at which they employ their money: they can reduce the interest they pay in proportion to that which they can make. The vital point to them is to employ it at some rate…

The fluctuations in the value of money are therefore greater than those on the value of most other commodities. At times there is an excessive pressure to borrow it, and at times an excessive pressure to lend it, and so the price is forced up and down.

The relevant point in this context is the explicit statement that the interest, or discount, rate is set by the supply and demand for money. But there are a couple other noteworthy things. First, the concept of supply and demand is one of monopolistic competition, in which lenders are not price takers, but actively trade off markup against market share. And second, that the demand for money (i.e. credit) is highly inelastic because money is needed not only or mainly to purchase goods and services, but first and foremost to meet contractual money commitments.

[1] See Perry Mehrling’s useful review. Most of the text of Woodford’s textbook can be downloaded for free here. The introduction is nontechnical and is fascinating reading if you’re interested in this stuff.

[2] Which is sort of a problem for Noah Smith’s neo-Fisherite view.

[3] in the same speech, King observes that “During the 19th century, the Bank of England devoted considerable attention to making bank rate ‘effective’.” His implication is that central banks have always been able to control interest rates. But this is somewhat misleading, from my point of view: the Bank devoted so much attention to making its rate “effective” precisely because of the occasions when it failed to do so.

Liquidity Preference and Solidity Preference in the 19th Century

So I’ve been reading Homer and Sylla’s History of Interest Rates. One of the many fascinating things I’ve learned, is that in the market for federal debt, what we today call an inverted yield curve was at one time the norm.

From the book:

Three small loans floated in 1820–1821, principally to permit the continued redemption of high rate war loans, provide an interesting clue to investor preference… These were:

$4.7 million “5s of 1820,” redeemable in 1832; sold at 100 = 5%.
“6s of 1820,” redeemable at pleasure of United States; sold at 102 = 5.88%.
“5s of 1821,” redeemable in 1835; sold at 1051⁄8 =4.50%, and at 108 = 4.25%.

The yield was highest for the issue with early redemption risk and much lower for those with later redemption risks.

Nineteenth century government bonds were a bit different from modern bonds, in that the principal was repaid at the option of the borrower; repayment is usually not permitted until a certain date. [1] They were also sold with a fixed yield in terms of face value — that’s what the “5” and “6” refer to — but the actual yield depended on the discount or premium they were sold at. The important thing for our purposes is that the further away the earliest possible date of repayment is, the lower the interest rate — the opposite of the modern term premium. That’s what the passage above is saying.

The pattern isn’t limited to the 1820-21 bonds, either; it seems to exist through most of the 19th century, at least for the US. It’s the same with the massive borrowing during the Civil War:

In 1864, although the war was approaching its end, it had only been half financed. The Treasury was able to sell a large volume of bonds, but not at such favorable terms as the market price of its seasoned issues might suggest. Early in the year another $100 million of the 5–20s [bonds with a minimum maturity of 5 years and a maximum of 20] were sold and then a new longer issue was sold as follows:

1864—$75 million “6s” redeemable in 1881, tax-exempt; sold at 104.45 = 5.60%.

The Treasury soon made an attempt to sell 5s, which met with a lukewarm reception. In order to attract investors to the lower rate the Treasury extended the term to redemption from five to ten years and the maturity from twenty to forty years:

1864—$73 million “5%, 10–40s of 1864,” redeemable 1874, due in 1904, tax-exempt; sold at 100 = 5%.

Isn’t that striking? The Treasury couldn’t get investors to buy its shorter bonds at an acceptable rate, so they had to issue longer bonds instead. You wouldn’t see that story today.

The same pattern continues through the 1870s, with the new loans issue to refinance the Civil War debt. The first issue of bonds, redeemable in five to ten years sold at an interest rate of 5%; the next issue, redeemable in 13-15 years sold at 4.5%; and the last issue, redeemable in 27-29 years, sold at 4%. And it doesn’t seem like this is about expectations of a change in rates, like with a modern inverted yield curve. Investors simply were more worried about being stuck with uninvestable cash than about being stuck with unsaleable securities. This is a case where “solidity preference” dominates liquidity preference.

One possible way of explaining this in terms of Axel Leijonhufvud’s explanation of the yield curve.

The conventional story for why long loans normally have higher interest rates than short ones is that longer loans impose greater risks on lenders. They may not be able to convert the loan to cash if they need to make some payment before it matures, and they may suffer a capital loss if interest rates change during the life of the loan. But this can’t be the whole story, because short loans create the symmetric risk of not knowing what alternative asset will be available when the loan matures. In the one case, the lender risks a capital loss, but in the other case they risk getting a lower income. Why is “capital uncertainty” a greater concern than “income uncertainty”?

The answer, Leijonhufvud suggests, lies in

Keynes’ … “Vision” of a world in which currently active households must, directly or indirectly, hold their net worth in the form of titles to streams that run beyond their consumption horizon. The duration of the relevant consumption plan is limited by the sad fact that “in the Long Run, we are all dead.” But the great bulk of the “Fixed Capital of the modem world” is very long- term in nature and is thus destined to survive the generation which now owns it. This is the basis for the wealth effect of changes in asset values.

The interesting point about this interpretation of the wealth effect is that it also provides a price-theoretical basis for Keynes’ Liquidity Preference theory. … Keynes’ (as well as Hicks’) statement of this hypothesis has been repeatedly criticized for not providing any rationale for the presumption that the system as a whole wants to shed “capital uncertainty” rather than “income uncertainty.” But Keynes’ mortal consumers cannot hold land, buildings, corporate equities, British consols, or other permanent income sources “to maturity.” When the representative, risk-averting transactor is nonetheless induced by the productivity of roundabout processes to invest his savings in such income sources, he must be resigned to suffer capital uncertainty. Forward markets will therefore generally show what Hicks called a “constitutional weakness” on the demand side.

I would prefer not to express this in terms of households’ consumption plans. And I would emphasize that the problem with wealth in the form of long-lived production processes is not just that it produces income far into the future, but that wealth in this form is always in danger of losing its character as money. Once capital is embodied in a particular production process and the organization that carries it out, it tends to evolve into the means of carrying out that organization’s intrinsic purposes, instead of the capital’s own self-expansion. But for this purpose, the difference doesn’t matter; either way, the problem only arises once you have, as Leijonhufvud puts it, “a system ‘tempted’ by the profitability of long processes to carry an asset stock which turns over more slowly than [wealth owners] would otherwise want.”

The temptation of long-lived production processes is inescapable in modern economies, and explains the constant search for liquidity. But in the pre-industrial United States? I don’t think so. Long-lived means of production were much less important, and to the extent they did exist, they weren’t an outlet for money-capital. Capital’s role in production was to finance stocks of raw materials, goods in process and inventories. There was no such thing, I don’t think, as investment by capitalists in long-lived capital goods. And even land — the long-lived asset in most settings — was not really an option, since it was abundant. The early United States is something like Samuelson’s consumption-loan world, where there is no good way to convert command over current goods into future production. [2] So there is excess demand rather than excess supply for long-lasting sources of income.

The switch over to positive term premiums comes early in the 20th century. By the 1920s, short-term loans in the New York market consistently have lower rates than corporate bonds, and 3-month Treasury bills have rates below longer bonds. Of course the organization of financial markets changed quite a lot in this period too, so one wouldn’t want to read too much into this timing. But it is at least consistent with the Leijonhufvud story. Liquidity preference becomes dominant in financial markets only once there has been a decisive shift toward industrial production by long-lived firm using capital-intensive techniques, and once claims on those firms has become a viable outlet for money-capital.

* * *

A few other interesting points about 19th century US interest rates. First, they were remarkably stable, at least before the 1870s. (This fits with the historical material on interest rates that Merijn Knibbe has been presenting in his excellent posts at Real World Economics Review.)

Second, there’s no sign of a Fisher equation. Nominal interest rates do not respond to changes in the price level, at all. Homer and Sylla mention that in earlier editions of the book, which dealt less with the 20th century, the concept of a “real” interest rate was not even mentioned.

As you can see from this graph, none of the major inflations or deflations between 1850 and 1960 had any effect on nominal interest rates. The idea that there is a fundamentals-determined “real” interest rate while the nominal rate adjusts in response to changes in the price level, clearly has no relevance outside the past 50 years. (Whether it describes the experience of the past 50 years either is a question for another time.)

Finally, there is no sign of “crowding out” of private by public borrowing. It is true that the federal government did have to pay somewhat higher rates during the periods of heavy borrowing (and of course also political uncertainty) in the War of 1812 and the Civil War. But rates for other borrowers didn’t budge. And on the other hand, the surpluses that resulted in the redemption of the entire debt in the 1830s didn’t deliver lower rates for other borrowers. Homer and Sylla:

Boston yields were about the same in 1835, when the federal debt was wiped out, as they were in 1830; this reinforces the view that there was little change in going rates of long-term interest during this five- year period of debt redemption.

If government borrowing really raises rates for private borrowers, you ought to see it here, given the absence of a central bank for most of this period and the enormous scale of federal borrowing during the Civil War. But you don’t.

[1] It seems that most, though not all, bonds were repaid at the earliest possible redemption date, so it is reasonably similar to the maturity of a modern bond.

[2] Slaves are the big exception. So the obvious test for the argument I am making here would be to find the modern pattern of term premiums in the South. Unfortunately, Homer and Sylla aren’t any help on this — it seems the only local bond markets in this period were in New England.

The Interest Rate, the Interest Rate, and Secular Stagnation

In the previous post, I argued that the term “interest rate” is used to refer to two basically unrelated prices: The exchange rate between similar goods at different periods, and the yield on a credit-market instrument. Why does this distinction matter for secular stagnation?

Because if you think the “natural rate of interest,” in the sense of the credit-market rate that brings aggregate expenditure to a desired level in some real-world economic situation, should be the time-substitution rate that would exist in a model that somehow corresponds to that situation, when the two are in fact unrelated — well then, you are going to end up with a lot of irrelevant and misleading intuitions about what that rate should be.

In general, I do think the secular stagnation conversation is a real step forward. So it’s a bit frustrating, in this context, to see Krugman speculating about the “natural rate” in terms of a Samuelson-consumption loan model, without realizing that the “interest rate” in that model is the intertemporal substitution rate, and has nothing to do with the Wicksellian natural rate. This was the exact confusion introduced by Hayek, which Sraffa tore to pieces in his review, and which Keynes went to great efforts to avoid in General Theory. It would be one thing if Krugman said, “OK, in this case Hayek was right and Keynes was wrong.” But in fact, I am sure, he has no idea that he is just reinventing the anti-Keynesian position in the debates of 75 years ago.

The Wicksellian natural rate is the credit-market rate that, in current conditions, would bring aggregate expenditure to the level desired by whoever is setting monetary policy. Whether or not there is a level of expenditure that we can reliably associate with “full employment” or “potential output” is a question for another day. The important point for now is “in current conditions.” The level of interest-sensitive expenditure that will bring GDP to the level desired by policymakers depends on everything else that affects desired expenditure — the government fiscal position, the distribution of income, trade propensities — and, importantly, the current level of income itself. Once the positive feedback between income and expenditure has been allowed to take hold, it will take a larger change in the interest rate to return the economy to its former position than it would have taken to keep it there in the first place.

There’s no harm in the term “natural rate of interest” if you understand it to mean “the credit market interest rate that policymakers should target to get the economy to the state they think it should be in, from the state it in now.”And in fact, that is how working central bankers do understand it. But if you understand “natural rate” to refer to some fundamental parameter of the economy, you will end up hopelessly confused. It is nonsense to say that “We need more government spending because the natural rate is low,” or “we have high unemployment because the natural rate is low.” If G were bigger, or if unemployment weren’t high, there would be a different natural rate. But when you don’t distinguish between the credit-market rate and time-substitution rate, this confusion is unavoidable.

Keynes understood clearly that it makes no sense to speak of the “natural rate of interest” as a fundamental characteristic of an economy, independent of the current state of aggregate demand:

In my Treatise on Money I defined what purported to be a unique rate of interest, which I called the natural rate of interest — namely, the rate of interest which, in the terminology of my Treatise, preserved equality between the rate of saving (as there defined) and the rate of investment. I believed this to be a development and clarification of Wicksell’s “natural rate of interest”, which was, according to him, the rate which would preserve the stability if some, not quite clearly specified, price-level.

I had, however, overlooked the fact that in any given society there is, on this definition, a different natural rate of interest for each hypothetical level of employment. And, similarly, for every rate of interest there is a level of employment for which that rate is the “natural” rate, in the sense that the system will be in equilibrium with that rate of interest and that level of employment. Thus it was a mistake to speak of the natural rate of interest or to suggest that the above definition would yield a unique value for the rate of interest irrespective of the level of employment. I had not then understood that, in certain conditions, the system could be in equilibrium with less than full employment.

I am now no longer of the opinion that the concept of a “natural” rate of interest, which previously seemed to me a most promising idea, has anything very useful or significant to contribute to our analysis. It is merely the rate of interest which will preserve the status quo; and, in general, we have no predominant interest in the status quo as such.

EDIT: In response to Nick Edmonds in comments, I’ve tried to restate the argument of these posts in simpler and hopefully clearer terms:

Step 1 is to recognize that in a model like Samuelson’s, “interest rate” just means any contract that allows you to make a payment today and receive a flow of income in the future. It would be the exact same model, capturing the exact same features of the economy, if we wrote “profit rate” or “house price-to-rent ratio” instead of “interest rate.” Any valid intuition the model gives us, applies to ALL asset yields, not just to the the credit-instrument yields that we call “interest rates” in every day life.

Step 2 is to think about the other factors that enter into real-world asset yields, besides the intertemporal exchange rate Samuelson is interested in — risk, liquidity, carrying costs and depreciation, and expected capital gains. Since all real-world asset yields incorporate at least one of these factors, none correspond exactly to Samuelson’s intertemporal interest rate.

Step 3 is to realize that not only are credit-instrument yields not exactly the Samuelson “interest rate,” they aren’t even approximately it. The great majority of credit market transactions we see in real economies are not exchanges of present income for future income, but exchanges of two different claims on future income. So the intertemporal interest rate enters on both sides and cancels out.

At that point, we have established that the “interest rate” the monetary authority is targeting is not the “interest rate” Samuelson is writing about.

Step 4 is then to ask, what does it mean to say that some particular credit-market interest rate is the “natural” one? That is where the dependence on fiscal policy, income distribution, etc. come in. But those factors are not part of the argument for why the credit-market rate is not even approximately the intertemporal rate.

The Interest Rate and the Interest Rate

We will return to secular stagnation. But we need to clear some ground first. What is an interest rate?

Imagine you are in a position to acquire a claim on a series of payments in the future. Since an asset is just anything that promises a stream of payments in the future, we will say you are thinking of buying of an asset. What will you look at to make your decision?

First is the size of the payments you will receive, as a fraction of what you pay today. We will call that the yield of the asset, or y. Against that we have to set the risk that the payments may be different from expected or not occur at all; we will call the amount you reduce your expected yield to account for this risk r. If you have to make regular payments beyond the purchase of the asset to receive income from it (perhaps taxes, or the costs of operating the asset if it is a capital good) then we also must subtract these carrying costs c. In addition, the asset may lose value over time, in which case we have to subtract the depreciation rate d. (In the case of an asset that only lasts one period — a loan to be paid back in full the next period, say — d will be equal to one.) On the other hand, owning an asset can have benefits beyond the yield. In particular, an asset can be sold or used as collateral. If this is easy to do, ownership of the asset allows you to make payments now, without having to waiting for its yield in the future. We call the value of the asset for making unexpected payments its liquidity premium, l. The market value of long-lasting assets may also change over time; assuming resale is possible, these market value changes will produce a capital gain g (positive or negative), which must be added to the return. Finally, you may place a lower value on the payments from the asset simply because they take place in the future; this might be because your needs now are more urgent than you expect them to be then, or simply because you prefer income in the present to income in the future. Either way, we have to subtract this pure time-substitution rate i.

So the value of an asset costing one unit (of whatever numeraire) will be 1 + y – r – c – d + l + g – i.

(EDIT: On rereading, this could use some clarification:

Of course all the terms can take on different (expected) values in different time periods, so they are vectors, not scalars. But if we assume they are constant, and that the asset lasts forever (i.e. a perpetuity), then we should write its equilibrium value as: V = Y/i, where Y is the total return in units of the numeraire, i.e. Y = V(y – r – c + l + g) and i is the discount rate. Divide through both sides by V and we have i = y – r – c + l + g. We can now proceed as below.)

In equilibrium, you should be just indifferent between purchasing and not purchasing this asset, so we can write:

y – r – c – d + l + g – i = 0, or

(1) y = r + c + d – l – g + i

So far, there is nothing controversial.

In formal economics, from Bohm-Bawerk through Cassel, Fisher and Samuelson to today’s standard models, the practice is to simplify this relationship by assuming that we can safely ignore most of these terms. Risk, carrying costs and depreciation can be netted out of yields, capital gains must be zero on average, and liquidity is assumed not to matter or just ignored. So then we have:

(2) y = i

In these models, it doesn’t matter if we use the term “interest rate” to mean y or to mean i, since they are always the same.

This assumption is appropriate for a world where there is only one kind of asset — a risk-free contract that exchanges one good in the present for 1 + i goods in the future. There’s nothing wrong with exploring what the value of i would be in such a world under various assumptions.

The problem arises when we carry equation (2) over to the real world and apply it to the yield of some particular asset. On the one hand, the yield of every existing asset reflects some or all of the other terms. And on the other hand, every contract that involves payments in more than one period — which is to say, every asset — equally incorporates i. If we are looking for the “interest rate” of economic theory in the economic world we observe around us, we could just as well pick the rent-price ratio for houses, or the profit rate, or the deflation rate, or the ratio of the college wage premium to tuition costs. These are just the yields of a house, of a share of the capital stock, of cash and of a college degree respectively. All of these are a ratio of expected future payments to present cost, and should reflect i to exactly the same extent as the yield of a bond does. Yet in everyday language, it is the yield of the bond that we call “interest”, even though it has no closer connection to the interest rate of theory than any of these other yields do.

This point was first made, as far as I know, by Sraffa in his review of Hayek’s Prices and Production. It was developed by Keynes, and stated clearly in chapters 13 and 17 of the General Theory.

For Keynes, there is an additional problem. The price we observe as an “interest rate” in credit markets is not even the y of the bond, which would be i modified by risk, expected capital gains and liquidity. That is because bonds do not trade against baskets of goods. They trade against money. When we see a bond being sold with a particular yield, we are not observing the exchange rate between a basket of goods equivalent to the bond’s value today and baskets of goods equivalent to its yield in the future. We are observing the exchange rate between the bond today and a quantity of money today. That’s what actually gets exchanged. So in equilibrium the price of the bond is what equates the expected returns on the two assets:

(3) y_B – r_B + l_B + g_B – i = l_M – i

(Neither bonds nor money depreciate or have carrying costs, and money has no risk. If our numeraire is money then money also cannot experience capital gains. If our numeraire was a basket of goods instead, then -g would be expected inflation, which would appear on both sides and cancel out.)

What we see is that i appears on both sides, so it cancels out. The yield of the bond is given by:

(4) y_B = r_B – g_B + (l_M – l_B)

The yield of the bond — the thing that in conventional usage we call the “interest rate” — depends on the risk of the bond, the expected price change of the bond, and the liquidity premium of money compared with the bond. Holding money today, and holding a bond today, are both means to enable you to make purchases in the future. So the intertemporal substitution rate i does not affect the bond yield.

(We might ask whether the arbitrage exists that would allow us to speak of a general rate of time-substitution i in real economies at all. But for present purposes we can ignore that question and focus on the fact that even if there is such a rate, it does not show up in the yields we normally call “interest rates”.)

This is the argument as Keynes makes it. It might seem decisive. But monetarists would reject it on the grounds that nobody in fact holds money as a store of value, so equation (3) does not apply. The bond-money market is not in equilibrium, because there is zero demand for money beyond that needed for current transactions at any price. (The corollary of this is the familiar monetarist claim that any change in the stock of money must result in a proportionate change in the value of transactions, which at full employment means a proportionate rise in the price level.) From the other side, endogenous money theorists might assert that the money supply is infinitely elastic for any credit-market interest rate, so l_M is endogenous and equation (4) is underdetermined.

As criticisms of the specific form of Keynes’ argument, these are valid objections. But if we take a more realistic view of credit markets, we come to the same conclusion: the yield on a credit instrument (call this the “credit interest rate”) has no relationship to the intertemporal substitution rate of theory (call this the “intertemporal interest rate.”)

Suppose you are buying a house, which you will pay for by taking out a mortgage equal to the value of the house. For simplicity we will assume an amortizing mortgage, so you make the same payment each period. We can also assume the value of housing services you receive from the house will also be the same each period. (In reality it might rise or fall, but an expectation that the house will get better over time is obviously not required for the transaction to take place.) So if the purchase is worth making at all, then it will result in a positive income to you in every period. There is no intertemporal substitution on your side. From the bank’s point of view, extending the mortgage means simultaneously creating an asset — their loan to you — and a liability — the newly created deposit you use to pay for the house. If the loan is worth making at all, then the expected payments from the mortgage exceed the expected default losses and other costs in every period. And the deposits are newly created, so no one associated with the bank has to forego any other expenditure in the present. There is no intertemporal substitution on the bank’s side either.

(It is worth noting that there are no net lenders or net borrowers in this scenario. Both sides have added an asset and a liability of equal value. The language of net lenders and net borrowers is carried over from models with consumption loans at the intertemporal interest rate. It is not relevant to the credit interest rate.)

If these transactions are income-positive for all periods for both sides, why aren’t they carried to infinity? One reason is that the yields for the home purchaser fall as more homes are purchased. In general, you will not value the housing services from a second home, or the additional housing services of a home that costs twice as much, as much as you value the housing services of the home you are buying now. But this only tells us that for any given interest rate there is a volume of mortgages at which the market will clear. It doesn’t tell us which of those mortgage volume-interest rate pairs we will actually see.

The answer is on the liquidity side. Buying a house makes you less liquid — it means you have less flexibility if you decide you’d like to move elsewhere, or if you need to reduce your housing costs because of unexpected fall in income or rise in other expenses. You also have a higher debt-income ratio, which may make it harder for you to borrow in the future. The loan also makes the bank less liquid — since its asset-capital ratio is now higher, there are more states of the world in which a fall in income would require it to sell assets or issue new liabilities to meet its scheduled commitments, which might be costly or, in a crisis, impossible. So the volume of mortgages rises until the excess of housing service value over debt service costs make taking out a mortgage just worth the incremental illiquidity for the marginal household, and where the excess of mortgage yield over funding costs makes issuing a new mortgage just worth the incremental illiquidity for the marginal bank. (Incremental illiquidity in the interbank market may — or may not — mean that funding costs rise with the volume of loans, but this is not necessary to the argument.)

Monetary policy affects the volume of these kinds of transactions by operating on the l terms. Normally, it does so by changing the quantity of liquid assets available to the financial system (and perhaps directly to the nonfinancial private sector as well). In this way the central bank makes banks (and perhaps households and businesses) more or less willing to accept the incremental illiquidity of a new loan contract. Monetary policy has nothing to do with substitution between expenditure in the present period and expenditure in some future period. Rather, it affects the terms of substitution between more and less liquid claims on income in the same future period.

Note that changing the quantity of liquid assets is not the only way the central bank can affect the liquidity premium. Banking regulation, lender of last resort operations and bailouts also change the liquidity premium, by chaining the subjective costs of bank balance sheet expansion. An expansion of the reserves available to the banking system makes it cheaper for banks to acquire a cushion to protect themselves against the possibility of an unexpected fall in income. This will make them more willing to hold relatively illiquid assets like mortgages. But a belief that the Fed will take emergency action prevent a bank from failing in the event of an unexpected fall in income also increases its willingness to hold assets like mortgages. And it does so by the same channel — reducing the liquidity premium. In this sense, there is no difference in principle between monetary policy and the central bank’s role as bank supervisor and lender of last resort. This is easy to understand once you think of “the interest rate” as the price of liquidity, but impossible to see when you think of “the interest rate” as the price of time substitution.

It is not only the central bank that changes the liquidity premium. If mortgages become more liquid — for instance through the development of a regular market in securitized mortgages — that reduces the liquidity cost of mortgage lending, exactly as looser monetary policy would.

The irrelevance of the time-substitution rate i to the credit-market interest rate y_B becomes clear when you compare observed interest rates with other prices that also should incorporate i. Courtesy of commenter rsj at Worthwhile Canadian Initiative, here’s one example: the Baa bond rate vs. the land price-rent ratio for residential property.

Both of these series are the ratio of one year’s payment from an asset, to the present value of all future payments. So they have an equal claim to be the “interest rate” of theory. But as we can see, none of the variation in credit-market interest rates (y_B, in my terms) show up in the price-rent ratio. Since variation in the time-substituion rate i should affect both ratios equally, this implies that none of the variation in credit-market interest rates is driven by changes in the time-substitution interest rate. The two “interest rates” have nothing to do with each other.

(Continued here.)

EDIT: Doesn’t it seem strange that I first assert that mortgages do not incorporate the intertemporal interest rate, then use the house price-rent ratio as an example of a price that should incorporate that rate? One reason to do this is to test the counterfactual claim that interest rates do, after all, incorporate Samuelson’s interest rate i. If i were important in both series, they should move together; if they don’t, it might be important in one, or in neither.

But beyond that, I think housing purchases do have an important intertemporal component, in a way that loan contracts do not. That’s because (with certain important exceptions we are all aware of) houses are not normally purchased entirely on credit. A substantial fraction of the price is paid is upfront. In effect, most house purchases are two separate transactions bundled together: A credit transaction (for, say, 80 percent of the house value) in which both parties expect positive income in all periods, at the cost of less liquid balance sheets; and a conceptually separate cash transaction (for, say, 20 percent) in which the buyer foregoes present expenditure in return for a stream of housing services in the future. Because house purchases must clear both of these markets, they incorporate i in way that loans do not. But note, i enters into house prices only to the extent that the credit-market interest rate does not. The more important the credit-market interest rate is in a given housing purchase, the less important the intertemporal interest rate is.

This is true in general, I think. Credit markets are not a means of trading off the present against the future. They are a means of avoiding tradeoffs between the present and the future.

Secular Stagnation, Progress in Economics

It’s the topic of the moment. Our starting point is this Paul Krugman post, occasioned by this talk by Lawrence Summers.

There are two ways to understand “secular stagnation.” One is that the growth rate of income and output will be slower in the future. The other is that there will be a systematic tendency for aggregate demand to fall short of the economy’s potential output. It’s the second claim that we are interested in.

For Krugman, the decisive fact about secular stagnation is that it implies a need for persistently negative interest rates. That achieved, there is no implication that growth rates or employment need to be lower in the future than in the past. He is imagining a situation where current levels of employment and growth rates are maintained, but with permanently lower interest rates.

We could also imagine a situation where full employment was maintained by permanently higher public spending, rather than lower interest rates. Or we could imagine a situation where nothing closed the gap and output fell consistently short of potential. What matters is that aggregate expenditure by the private sector tends to fall short of the economy’s potential output, by a growing margin. For reasons I will explain down the road, I think this is a better way of stating the position than a negative “natural rate” of interest.

I think this conversation is a step forward for mainstream macroeconomic thought. There are further steps still to take. In this post I describe what, for me, are the positive elements of this new conversation. In subsequent posts, I will talk about the right way of analyzing these questions more systematically — in terms of a Harrod-type growth model — and about the wrong way — in terms of the natural rate of interest.

The positive content of “secular stagnation”

1. Output is determined by demand.

The determination of total output by total expenditure is such a familiar part of the macroeconomics curriculum that we forget how subversive it is. It denies the logic of scarcity that is the basis of economic analysis and economic morality. Since Mandeville’s Fable of the Bees, it’s been recognized that if aggregate expenditure determines aggregate income, then, as Krugman says, “vice is virtue and virtue is vice.”

A great deal of the history of macroeconomics over the past 75 years can be thought of as various efforts to expunge, exorcize or neutralize the idea of demand-determined income, or at least to safely quarantine it form the rest of economic theory. One of the most successful quarantine strategies was to recast demand constraints on aggregate output as excess demand for money, or equivalently as the wrong interest rate. What distinguished real economies from the competitive equilibrium of Jevons or Walras was the lack of a reliable aggregate demand “thermostat”. But if a central bank or other authority set that one price or that one quantity correctly, economic questions could again be reduced to allocation of scarce means to alternative ends, via markets. Both Hayek and Friedman explicitly defined the “natural rate” of interest, which monetary policy should maintain, as the rate that would exist in a Walrasian barter economy. In postwar and modern New Keynesian mainstream economics, the natural rate is defined as the market interest rate that produces full employment and stable prices, without (I think) explicit reference to the intertemporal exchange rate that is called the interest rate in models of barter economies. But he equivalence is still there implicitly, and is the source of a great deal of confusion.

I will return to the question of what connection there is, if any, between the interest rates we observe in the world around us, and what a paper like Samuelson 1958 refers to as the “interest rate.” The important thing for present purposes is:

Mainstream economic theory deals with the problems raised when expenditure determines output, by assuming that the monetary authority sets an interest rate such that expenditure just equals potential output. If such a policy is followed successfully, the economy behaves as if it were productive capacity that determined output. Then, specifically Keynesian problems can be ignored by everyone except the monetary-policy technicians. One of the positive things about the secular stagnation conversation, from my point of view, is that it lets Keynes back out of this box.

That said, he is only partway out. Even if it’s acknowledged that setting the right interest rate does not solve the problem of aggregate demand as easily as previously believed, the problem is still framed in terms of the interest rate.

2. Demand normally falls short of potential

Another strategy to limit the subversive impact of Keynes has been to consign him to the sublunary domain of the short run, with the eternal world of long run growth still classical. (It’s a notable — and to me irritating — feature of macroeconomics textbooks that the sections on growth seem to get longer over time, and to move to the front of the book.) But if deviations from full employment are persistent, we can’t assume they cancel out and ignore them when evaluating an economy’s long-run trajectory.

One of the most interesting parts of the Summers talk came when he said, “It is a central pillar of both classical models and Keynesian models, that it is all about fluctuations, fluctuations around a given mean.” (He means New Keynesian models here, not what I would consider the authentic Keynes.) “So what you need to do is have less volatility.” He introduces the idea of secular stagnation explicitly as an alternative to this view that demand matters only for the short run. (And he forthrightly acknowledges that Stanley Fischer, his MIT professor who he is there to praise, taught that demand is strictly a short-run phenomenon.) The real content of secular stagnation, for Summers, is not slower growth itself, but the possibility that the same factors that can cause aggregate expenditure to fall short of the economy’s potential output can matter in the long run as well as in the short run.

Now for Summers and Krugman, there still exists a fundamentals-determined potential growth rate, and historically the level of activity did fluctuate around it in the past. Only in this new era of secular stagnation, do we have to consider the dynamics of an economy where aggregate demand plays a role in long-term growth. From my point of view, it’s less clear that anything has changed in the behavior of the economy. “Secular stagnation” is only acknowledging what has always been true. The notion of potential output was never well defined. Labor supply and technology, the supposed fundamentals, are strongly influenced by the level of capacity utilization. As I’ve discussed before, once you allow for Verdoorn’s Law and hysteresis, it makes no sense to talk about the economy’s “potential growth rate,” even in principle. I hope the conversation may be moving in that direction. Once you’ve acknowledged that the classical allocation-of-scarce-means-to-alternative-ends model of growth doesn’t apply in present circumstances, it’s easier to take the next step and abandon it entirely.

3. Bubbles are functional

One widely-noted claim in the Summers talk is that asset bubbles have been a necessary concomitant of full employment in the US since the 1980s. Before the real estate bubble there was the tech bubble, and before that there was the commercial real estate bubble we remember as the S&L crisis. Without them, the problem of secular stagnation might have posed itself much earlier.

This claim can be understood in several different, but not mutually exclusive, senses. It may be (1) interest rates sufficiently low to produce full employment, are also low enough to provoke a bubble. It may be (2) asset bubbles are an important channel by which monetary policy affects real activity. Or it may be (3) bubbles are a substitute for the required negative interest rates. I am not sure which of these claims Summers intends. All three are plausible, but it is still important to distinguish them. In particular, the first two imply that if interest rates could fall enough to restore full employment, we would have even more bubbles — in the first case, as an unintended side effect of the low rates, in the second, as the channel through which they would work. The third claim implies that if interest rates could fall enough to restore full employment, it would be possible to do more to restrain bubbles.

An important subcase of (1) comes when there is a minimum return that owners of money capital can accept. As Keynes said (in a passage I’m fond of quoting),

The most stable, and the least easily shifted, element in our contemporary economy has been hitherto, and may prove to be in future, the minimum rate of interest acceptable to the generality of wealth-owners.[2] If a tolerable level of employment requires a rate of interest much below the average rates which ruled in the nineteenth century, it is most doubtful whether it can be achieved merely by manipulating the quantity of money. Cf. the nineteenth-century saying, quoted by Bagehot, that “John Bull can stand many things, but he cannot stand 2 per cent.”

If this is true, then asking owners of money wealth to accept rates of 2 percent, or perhaps much less, will face political resistance. More important for our purposes, it will create an inclination to believe the sales pitch for any asset that offers an acceptable return.

Randy Wray says that Summers is carrying water here for his own reputation and his masters in Finance. The case for bubbles as necessary for full employment justifies his past support for financial deregulation, and helps make the case against any new regulation in the future. That may be true. But I still think he is onto something important. There’s a long-standing criticism of market-based finance that it puts an excessive premium on liquidity and discourages investment in long-lived assets. A systematic overestimate of the returns from fixed assets might be needed to offset the systematic overestimate of the costs of illiquidity.

Another reason I like this part of Summers’ talk is that it moves us toward recognizing the fundamental symmetry between between monetary policy conventionally defined, lender of last resort operations and bank regulations. These are different ways of making the balance sheets of the financial sector more or less liquid. The recent shift from talking about monetary policy setting the money stock to talking about setting interest interest rates was in a certain sense a step toward realism, since there is nothing in modern economies that corresponds to a quantity of money. But it was also a step toward greater abstraction, since it leaves it unclear what is the relationship between the central bank and the banking system that allows the central bank to set the terms of private credit transactions. Self-interested as it may be, Summers call for regulatory forbearance here is an intellectual step forward. It moves us toward thinking of what central banks do neither in terms of money, nor in terms of interest rates, but in terms of liquidity.

Finally, note that in Ben Bernanke’s analysis of how monetary policy affects output, asset prices are an important channel. That is an argument for version (2) of the bubbles claim.

4. High interest rates are not coming back

For Summers and Krugman, the problem is still defined in terms of a negative “natural rate” of interest. (To my mind, this is the biggest flaw in their analysis.) So much of the practical discussion comes down to how you convince or compel wealth owners to hold assets with negative yields. One solution is to move to permanently higher inflation rates. (Krugman, to his credit, recognizes that this option will only be available when or if something else raises aggregate demand enough to push against supply constraints.) I am somewhat skeptical that capitalist enterprises in their current form can function well with significantly higher inflation. The entire complex of budget and invoicing practices assumes that over some short period — a month, a quarter, even a year — prices can be treated as constant. Maybe this is an easy problem to solve, but maybe not. Anyway, it would be an interesting experiment to find out!

More directly relevant is the acknowledgement that interest rates below growth rates may be a permanent feature of the economic environment for the foreseeable future. This has important implications for debt dynamics (both public and private), as we’ve discussed extensively on this blog. I give Krugman credit for saying that with i < g, it is impossible for debt to spiral out of control; a deficit of any level, maintained forever, will only ever cause the debt-GDP ratio to converge to some finite level. (I also give him credit for acknowledging that this is a change in his views.) This has the important practical effect of knocking another leg out from the case for austerity. It’s been a source of great frustration for me to see so many liberal, “Keynesian” economists follow every argument for stimulus with a pious invocation of the need for long-term deficit reduction. If people no longer feel compelled to bow before that shrine, that is progress.

On a more abstract level, the possibility of sub-g or sub-zero interest rates helps break down the quarantining of Keynes discussed above. Mainstream economists engage in a kind of doublethink about the interest rate. In the context of short-run stabilization, it is set by the central bank. But in other contexts, it is set by time preferences and technological tradeoff between current and future goods. I don’t think there was ever any coherent way to reconcile these positions. As I will explain in a following post, the term “interest rate” in these two contexts is being used to refer to two distinct and basically unrelated prices. (This was the upshot of the Sraffa-Hayek debate.) But as long as the interest rate observed in the world (call it the “finance” interest rate) behaved similarly enough to the interest rate in the models (the “time-substitution” interest rate), it was possible to ignore this contradiction without too much embarrassment.

There is no plausible way that the “time substitution” interest rate can be negative. So the secular stagnation conversation is helping reestablish the point — made by Keynes in chapter 17 of the General Theory, but largely forgotten — that the interest rates we observe in the world are something different. And in particular, it is no longer defensible to treat the interest rate as somehow exogenous to discussions about aggregate demand and fiscal policy. When I was debating fiscal policy with John Quiggin, he made the case for treating debt sustainability as a binding constraint by noting that there are long periods historically when interest rates were higher than growth rates. It never occurred to him that it makes no sense to talk about the level of interest rates as an objective fact, independent of the demand conditions that make expansionary fiscal policy desirable. I don’t mean to pick on John — at the time it wasn’t clear to me either.

Finally, on the topic of low interest forever, I liked Krugman’s scorn for the rights of interest-recipients:

How dare anyone suggest that virtuous individuals, people who are prudent and save for the future, face expropriation? How can you suggest steadily eroding their savings either through inflation or through negative interest rates? It’s tyranny!
But in a liquidity trap saving may be a personal virtue, but it’s a social vice. And in an economy facing secular stagnation, this isn’t just a temporary state of affairs, it’s the norm. Assuring people that they can get a positive rate of return on safe assets means promising them something the market doesn’t want to deliver – it’s like farm price supports, except for rentiers.

It’s a nice line, only slightly spoiled by the part about “what the market wants to deliver.” The idea that it is immoral to deprive the owners of money wealth of their accustomed returns is widespread and deeply rooted. I think it lies behind many seemingly positive economic claims. If this conversation develops, I expect we will see more open assertions of the moral entitlement of the rentiers.

Don’t Touch the Yield

There’s a widespread idea in finance and economics land that there’s something wrong, dangerous, even unnatural about persistently low interest rates.

This idea takes its perhaps most reasonable form in arguments that the fundamental cause of the Great Financial Crisis was rates that were “far too low for far too long,” and that continued low interest rates, going forward, will only encourage speculation and new asset bubbles. Behind, or anyway alongside, these kinds of claims is a more fundamentally ideological view, that owners of financial assets are morally entitled to their accustomed returns, and woe betide the society or central banker that deprives them of the fruit of their non-labor. You hear this when certain well-known economists describe low rates as the “rape and plunder” of bondowners, or when Jim Grant says that the real victims of the recession are investors in money-market funds.

I want to look today at the “reaching for yield” version of this argument, which Brad Delong flagged as PRIORITY #1 RED FLAG OMEGA for the econosphere after it was endorsed by the Federal Reserve’s Jeremy Stein. [1] In DeLong’s summary:

Bankers want profits. … And a bank has costs above and beyond the returns on its portfolio. For each dollar of deposits it collects, a bank must spend 2.5 cents per year servicing those deposits. In normal times, when interest rates are well above 2.5 percent per year, banks have a normal, sensible attitude to risk and return. They will accept greater risk only if they come with returns higher enough to actually diminish the chances of reporting a loss. But when interest rates fall low enough that even the most sensible portfolio cannot reliably deliver a return on the portfolio high enough to cover the 2.5 cent per year cost of managing deposits, a bank will “reach for yield” and start writing correlated unhedged out-of-the-money puts so that it covers its 2.5 percent per year hurdle unless its little world blows up. Banks stop reducing their risk as falling returns mean that diversification and margin can no longer be counted on to manage them but instead embrace risks.

It is Stein’s judgment that right now whatever benefits are being provided to employment and production by the Federal Reserve’s super-sub-normal interest rate policy and aggressive quantitative easing are outweighed by the risks being run by banks that are reaching for yield.

Now on one level, this just seems like a non-sequitur. “Banks holding more risky assets” is, after all, just another way of saying “banks making more loans.” In fact, it’s hard to see how monetary policy is ever supposed to work if we rule out the possibility of shifting banks’ demand for risky private assets. [1] An Austrian, I suppose, might follow this logic to its conclusion and reject the idea of monetary policy in general; but presumably not an Obama appointee to the Fed.

But there’s an even more fundamental problem, not only with the argument here but with the broader idea — shared even by people who should know better — that low interest rates hurt bank profits. It’s natural to think that banks receive interest payments, so lower interest means less money for the bankers. But that is wrong.

Banks are the biggest borrowers as well as the biggest lenders in the economy, so what matters is not the absolute level of interest rates, but the spread — the difference between the rate at which banks borrow and the rate at which they lend. A bank covers its costs as reliably borrowing at 1 percent and lending at 4, as it does borrowing at 3 percent and lending at 6. So if we want to argue that monetary policy affects the profitability of bank lending, we have to argue that it has a differential effect on banks funding costs and lending rates.

For many people making the low-rates-are-bad-for-banks argument, this differential effect may come from a mental model in which the main bank liabilities are non-interest-bearing deposits. Look at the DeLong quote again — in the world it’s describing, banks pay a fixed rate on their liabilities. And at one point that is what the real world looked like too.

In 1960, non-interest-bearing deposits made up over two-thirds of total bank liabilities. In a system like that, it’s natural to see the effect of monetary policy as mainly on the asset side of bank balance sheets. But today’s bank balance sheets look very different: commercial banks now pay interest on around 80 percent of their liabilities. So it’s much less clear, a priori, why policy changes should affect banks interest income more than their funding costs. Since banks borrow short and lend long (that’s sort of what it means to be a bank), and since monetary policy has its strongest effects at shorter maturities, one might even expect the effect on spreads to go the other way.

And in fact, when we look at the data, that is what we see.

Average interest rate paid (red) and received (blue) by commercial banks. Source: FDIC

The black line with diamonds is the Federal Funds rate, set by monetary policy. The blue line is the average interest rate charged by commercial banks on all loans and leases; the solid red line is their average funding cost; and the dotted red line is the average interest rate on commercial banks’ interest-bearing liabilities. [3] As the figure shows, in the 1950s and ’60s changes in the federal funds rate didn’t move banks’ funding costs at all, while they did have some effect on loan rates; the reach-for-yield story might have made sense then. But in recent decades, as banks’ pool of cheap deposit funding has dried up, bank funding costs have become increasingly sensitive to the policy rate.

Looking at the most recent cycle, the decline in the Fed Funds rate from around 5 percent in 2006-2007 to the zero of today has been associated with a 2.5 point fall in bank funding costs but only a 1.5 point fall in bank lending rates — in other words, a one point increase in spreads. The same relationship, though weaker, is present in the previous two cycles, but not before. More generally, the correlation of changes in the federal funds rate and changes in bank spreads is 0.49 for 1955-1980, but negative 0.38 for the years 1991-2001. So Stein’s argument fails at the first step. If low bank margins are the problem, then “super-sub-normal interest rate policy” is the solution.

Let’s walk through this again. The thing that banks care about is the difference between what it costs them to borrow, and what they can charge to lend. Wider spreads mean lending is more profitable, narrower spreads mean it’s less so. And if banks need a minimum return on their lending — to cover fixed costs, or to pay executives expected bonuses or whatever — then when spreads get too narrow, banks may be tempted to take underprice risk. That’s “reaching for yield.” So turning to the figure, the spread is the space between the solid red line and the solid blue one. As we can see, in the 1950s and ’60s, when banks funded themselves mostly with deposits, the red line — their borrowing costs — doesn’t move at all with the federal funds rate. So for instance the sharp tightening at the end of the 1960s raises average bank lending rates by several points, but doesn’t move bank borrowing rates at all. So in that period, a high federal funds rate means wide bank spreads, and a low federal funds rate means narrower spreads. In that context the “reaching for yield” story has a certain logic (which is not to say it would be true, or important.) But since the 1980s, the red line — bank funding costs — has become much more responsive to the federal funds rate, so this relationship between monetary policy and bank spreads no longer exists. If anything, as I said, the correlation runs in the opposite direction.

Short version: When banks are funded by non-interest bearing deposits, low interest rates can hurt their profits, which makes them have a sad face. But when banks pay interest on almost all their liabilities, as today, low rates make them have a happy face. [4] In which case there’s no reason for them to reach for yield.

Now, it is true that the Fed has also intervened directly in the long end, where one might expect the impact on bank lending rates to be stronger. This is specifically the focus of a speech by Stein last October, where he explicitly said that if the policy rate were currently 3 percent he would have no objection to lowering it, but that he was more worried about unconventional policy to directly target long rates. [5] He offers a number of reasons why a fall in long rates due an expectation of lower short rates in the future would be expansionary, but a fall in long rates due to a lower term premium might not be. Frankly I find all these explanations ad-hoc and hand-wavey. But the key point for present purposes is that unconventional policy does not involve the central bank setting some kind of regulatory ceiling on long rates; rather, it involves lowering long rates via voluntary transactions with lenders. The way the Fed lowers rates on long bonds is by raising their price; the way it raises their price is by buying them. It is true, simply as a matter of logic, that the only way that QE can lower the market rate on a loan from, say, 4 percent to 3.9 percent, is by buying up enough loans (or rather, assets that are substitutes for loans) that the marginal lender now values a 3.9 percent loan the same as the marginal lender valued a 4 percent loan before. If a lender who previously would have considered a loan at 4 percent just worth making, does not now consider a loan at 3.9 percent worth making, then the interest rate on loans will not fall. Despite what John Taylor imagines, the Fed does not reduce interest rates by imposing a ceiling by fiat. So the statement, “if the Fed lowers long rates, bank won’t want to lend” is incoherent: the only way the Fed can lower long rates is by making banks want to lend more.

Stein’s argument is, to be honest, a bit puzzling. If it were true that banks respond to lower rates not by reducing lending or accepting lower profit margins, but by redoubling their efforts to fraudulently inflate returns, that would seem to be an argument for radically reforming the bank industry, or at least sending a bunch of bankers to jail. Stein, weirdly, wants it to be an argument for keeping rates perpetually high. But we don’t even need to have that conversation. Because what matters to banks is not the absolute level of rates, but the spread between their borrowing rate and their lending rate. And in the current institutional setting, expansionary policy implies higher spreads. Nobody needs to be reaching for yield.

[1] The DeLong post doesn’t give a link, but I think he’s responding to this February 7 speech.

[2] As Daniel Davies puts it in comments to the DeLong post:

If the Federal Reserve sets out on a policy of lowering interest rates in order to encourage banks to make loans to the real economy, it is a bit weird for someone’s main critique of the policy to be that it is encouraging banks to make loans. If Jeremy Stein worked for McDonalds, he would be warning that their latest ad campaign carried a risk that it might increase sales of delicious hamburgers.

[3] Specifically, these are commercial banks’ total interest payments from loans and leases divided by the total stock of loans and leases, and total interest payments divided by total liabilities and interest-bearing liabilities respectively.

[4] Why yes, I have been hanging around with a toddler lately.

[5] Interesting historical aside: Keynes’ conclusion in the 1930s that central bank intereventions could not restore full employment and that fiscal policy was therefore necessary, was not — pace the postwar Keynesian mainstream — based on any skepticism about the responsiveness of economic activity to interest rates in principle. It was, rather, based on his long-standing doubts about the reliability of the link from short rates to long rates, plus a new conviction that central banks would be politically unable or unwilling to target long rates directly.

Does the Fed Control Interest Rates?

Casey Mulligan goes to the New York Times to say that monetary policy doesn’t work. This annoys Brad DeLong:

THE NEW YORK TIMES PUBLISHES CASEY MULLIGAN AS A JOKE, DOESN’T IT?

… The third joke is the entire third paragraph: since the long government bond rate is made up of the sum of (a) an average of present and future short-term rates and (b) term and risk premia, if Federal Reserve policy affects short rates then–unless you want to throw every single vestige of efficient markets overboard and argue that there are huge profit opportunities left on the table by financiers in the bond market–Federal Reserve policy affects long rates as well.

Casey B. Mulligan: Who Cares About Fed Funds?: New research confirms that the Federal Reserve’s monetary policy has little effect on a number of financial markets, let alone the wider economy…. Eugene Fama of the University of Chicago recently studied the relationship between the markets for overnight loans and the markets for long-term bonds…. Professor Fama found the yields on long-term government bonds to be largely immune from Fed policy changes…

Krugman piles on [1]; the only problem with DeLong’s post, he says, is that

it fails to convey the sheer numbskull quality of Mulligan’s argument. Mulligan tries to refute people like, well, me, who say that the zero lower bound makes the case for fiscal policy. … Mulligan’s answer is that this is foolish, because monetary policy is never effective. Huh?

… we have overwhelming empirical evidence that monetary policy does in fact “work”; but Mulligan apparently doesn’t know anything about that.

Overwhelming evidence? Citation needed, as the Wikipedians say.

Anyway, I don’t want to defend Mulligan — I haven’t even read the column in question — but on this point, he’s got a point. Not only that: He’s got the more authentic Keynesian position.

Textbook macro models, including the IS-LM that Krugman is so fond of, feature a single interest rate, set by the Federal Reserve. The actual existence of many different interest rates in real economies is hand-waved away with “risk premia” — market rates are just equal to “the” interest rate plus a prmium for the expected probability of default of that particular borrower. Since the risk premia depnd on real factors, they should be reasonably stable, or at least independent of monetary policy. So when the Fed Funds rate goes up or down, the whole rate structure should go up and down with it. In which case, speaking of “the” interest rate as set by the central bank is a reasonable short hand.

How’s that hold up in practice? Let’s see:

The figure above shows the Federal Funds rate and various market rates over the past 25 years. Notice how every time the Fed changes its policy rate (the heavy black line) the market rates move right along with it?

Yeah, not so much.

In the two years after June 2007, the Fed lowered its rate by a full five points. In this same period, the rate on Aaa bonds fell by less 0.2 points, and rates for Baa and state and local bonds actually rose. In a naive look at the evidence, the “overwhelming” evidence for the effectiveness of monetary policy is not immediately obvious.

Ah but it’s not current short rates that long rates are supposed to follow, but expected short rates. This is what our orthodox New Keynesians would say. My first response is, So what? Bringing expectations in might solve the theoretical problem but it doesn’t help with the practical one. “Monetary policy doesn’t work because it doesn’t change expectations” is just a particular case of “monetary policy doesn’t work.”

But it’s not at all obvious that long rates follow expected short rates either. Here’s another figure. This one shows the spreads between the 10-Year Treasury and the Baa corporate bond rates, respectively, and the (geometric) average Fed Funds rate over the following 10 years.

If DeLong were right that “the long government bond rate is made up of the sum of (a) an average of present and future short-term rates and (b) term and risk premia” then the blue bars should be roughly constant at zero, or slightly above it. [2] Not what we see at all. It certainly looks as though the markets have been systematically overestimating the future level of the Federal Funds rate for decades now. But hey, who are you going to believe, the efficient markets theory or your lying eyes? Efficient markets plus rational expectations say that long rates must be governed by the future course of short rates, just as stock prices must be governed by future flows of dividends. Both claims must be true in theory, which means they are true, no matter how stubbornly they insist on looking false.

Of course if you want to believe that the inherent risk premium on long bonds is four points higher today than it was in the 1950s, 60s and 70s (despite the fact that the default rate on Treasuries, now as then, is zero) and that the risk premium just happens to rise whenever the short rate falls, well, there’s nothing I can do to stop you.

But what’s the alternative? Am I really saying that players in the bond market are leaving huge profit opportunities on the table? Well, sometimes, maybe. But there’s a better story, the one I was telling the other day.

DeLong says that if rates are set by rational, profit-maximizing agents, then — setting aside default risk — long rates should be equal to the average of short rates over their term. This is a standard view, everyone learns it. but it’s not strictly correct. What profit-maximizing bond traders do, is set long rates equal to the expected future value of long rates.

I went through this in that other post, but let’s do it again. Take a long bond — we’ll call it a perpetuity to keep the math simple, but the basic argument applies to any reasonably long bond. Say it has a coupon (annual payment) of $40 per year. If that bond is currently trading at $1000, that implies an interest rate of 4 percent. Meanwhile, suppose the current short rate is 2 percent, and you expect that short rate to be maintained indefinitely. Then the long bond is a good deal — you’ll want to buy it. And as you and people like you buy long bonds, their price will rise. It will keep rising until it reaches $2000, at which point the long interest rate is 2 percent, meaning that the expected return on holding the long bond and rolling over short bonds is identical, so there’s no incentive to trade one for the other. This is the arbitrage that is supposed to keep long rates equal to the expected future value of short rates. If bond traders don’t behave this way, they are missing out on profitable trades, right?

Not necessarily. Suppose the situation is as described above — 4 percent long rate, 2 percent short rate which you expect to continue indefinitely. So buying a long bond is a no-brainer, right? But suppose you also believe that the normal or usual long rate is 5 percent, and that it is likely to return to that level soon. Maybe you think other market participants have different expectations of short rates, maybe you think other market participants are irrational, maybe you think… something else, which we’ll come back to in a second. For whatever reason, you think that short rates will be 2 percent forever, but that long rates, currently 4 percent, might well rise back to 5 percent. If that happens, the long bond currently trading for $1000 will fall in price to $800. (Remember, the coupon is fixed at $40, and 5% = 40/800.) You definitely don’t want to be holding a long bond when that happens. That would be a capital loss of 20 percent. Of course every year that you hold short bonds rather than buying the long bond at its current price of $1000, you’re missing out on $20 of interest; but if you think there’s even a moderate chance of the long bond falling in value by $200, giving up $20 of interest to avoid that risk might not look like a bad deal.

Of course, even if you think the long bond is likely to fall in value to $800, that doesn’t mean you won’t buy it for anything above that. if the current price is only a bit above $800 (the current interest rate is only a bit below the “normal” level of 5 percent) you might think the extra interest you get from buying a long bond is enough to compensate you for the modest risk of a capital loss. So in this situation, the equilibrium price of the long bond won’t be at the normal level, but slightly below it. And if the situation continues long enough, people will presumably adjust their views of the “normal” level of the long bond to this equilibrium, allowing the new equilibrium to fall further. In this way, if short rates are kept far enough from long rates for long enough, long rates will eventually follow. We are seeing a bit of this process now. But adjusting expectations in this way is too slow to be practical for countercyclical policy. Starting in 1998, the Fed reduced rates by 4.5 points, and maintained them at this low level for a full six years. Yet this was only enough to reduce Aaa bond rates (which shouldn’t include any substantial default risk premium) by slightly over one point.

In my previous post, I pointed out that for policy to affect long rates, it must include (or be believed to include) a substantial permanent component, so stabilizing the economy this way will involve a secular drift in interest rates — upward in an economy facing inflation, downward in one facing unemployment. (As Steve Randy Waldman recently noted, Michal Kalecki pointed this out long ago.) That’s important, but I want to make another point here.

If the primary influence on current long rates is the expected future value of long rates, then there is no sense in which long rates are set by fundamentals. There are a potentially infinite number of self-fulfilling expected levels for long rates. And again, no one needs to behave irrationally for these conventions to sustain themselves. The more firmly anchored is the expected level of long rates, the more rational it is for individual market participants to act so as to maintain that level. That’s the “other thing” I suggested above. If people believe that long rates can’t fall below a certain level, then they have an incentive to trade bonds in a way that will in fact prevent rates from falling much below that level. Which means they are right to believe it. Just like driving on the right or left side of the street, if everyone else is doing it it is rational for you to do it as well, which ensures that everyone will keep doing it, even if it’s not the best response to the “fundamentals” in a particular context.

Needless to say, the idea that that long-term rate of interest is basically a convention straight from Keynes. As he puts it in Chapter 15 of The General Theory,

The rate of interest is a highly conventional … phenomenon. For its actual value is largely governed by the prevailing view as to what its value is expected to be. Any level of interest which is accepted with sufficient conviction as likely to be durable will be durable; subject, of course, in a changing society to fluctuations for all kinds of reasons round the expected normal.

You don’t have to take Keynes as gospel, of course. But if you’ve gotten as much mileage as Krugman has out of the particular extract of Keynes’ ideas embodied in the IS-LM mode, wouldn’t it make sense to at least wonder why the man thought this about interest rates, and if there might not be something to it.

Here’s one more piece of data. This table shows the average spread between various market rates and the Fed Funds rate.

Spreads over Fed Funds by decade
	10-Year Treasuries	Aaa Corporate Bonds	Baa Corporate Bonds	State & Local Bonds
1940s		2.2	3.3
1950s	1.0	1.3	2.0	0.7
1960s	0.5	0.8	1.5	-0.4
1970s	0.4	1.1	2.2	-1.1
1980s	0.6	1.4	2.9	-0.9
1990s	1.5	2.6	3.3	0.9
2000s	1.5	3.0	4.1	1.8

Treasuries carry no default risk; a given bond rating should imply a fixed level of default risk, with the default risk on Aaa bonds being practically negligible. [3] Yet the 10-year treasury spread has increased by a full point and the corporate bond rates by about two points, compared with the postwar era. (Municipal rates have risen by even more, but there may be an element of genuine increased risk there.) Brad DeLong might argue that society’s risk-bearing capacity has decline so catastrophically since the 1960s that even the tiny quantum of risk in Aaa bonds requires two full additional points of interest to compensate its quaking, terrified bearers. And that this has somehow happened without requiring any more compensation for the extra risk in Baa bonds relative to Aaa. I don’t think even DeLong would argue this, but when the honor of efficient markets is at stake, people have been known to do strange things.

Wouldn’t it be simpler to allow that maybe long rates are not, after all, set as “the sum of (a) an average of present and future short-term rates and (b) [relatively stable] term and risk premia,” but that they follow their own independent course, set by conventional beliefs that the central bank can only shift slowly, unreliably and against considerable resistance? That’s what Keynes thought. It’s what Alan Greenspan thinks. [4] And also it’s what seems to be true, so there’s that.

[1] Prof. T. asks what I’m working on. A blogpost, I say. “Let me guess — it says that Paul Krugman is great but he’s wrong about this one thing.” Um, as a matter of fact…

[2] There’s no risk premium on Treasuries, and it is not theoretically obvious why term premia should be positive on average, though in practice they generally are.

[3] Despite all the — highly deserved! — criticism the agencies got for their credulous ratings of mortgage-backed securities, they do seem to be good at assessing corporate default risk. The cumulative ten-year default rate for Baa bonds issued in the 1970s was 3.9 percent. Two decades later, the cumulative ten-year default rate for Baa bonds issued in the 1990s was … 3.9 percent. (From here, Exhibit 42.)

[4] Greenspan thinks that the economically important long rates “had clearly delinked from the fed funds rate in the early part of this decade.” I would only add that this was just the endpoint of a longer trend.