bad Paul Krugman bad bad

What Does Crowding Out Even Mean?

Paul Krugman is taking some guff for this column where he argues that the US economy is now at potential, or full employment, so any shift in the federal budget toward deficit will just crowd out private demand.

Whether higher federal spending (or lower taxes) could, in present conditions, lead to higher output is obviously a factual question, on which people may read the evidence in different ways. As it happens, I don’t agree that current output is close to the limits of current productive capacity. But that’s not what I want to write about right now. Instead I want to ask: What concretely would crowding out even mean right now?

Below, I run through six possible meanings of crowding out, and then ask if any of them gives us a reason, even in principle, to worry about over-expansionary policy today. (Another possibility, suggested by Jared Bernstein, is that while we don’t need to worry about supply constraints for the economy as a whole, tax cuts could crowd out useful spending due to some unspecified financial constraint on the federal government. I don’t address that here.) Needless to say, doubts about the economic case for crowding-out are in no way an argument for the specific deficit-boosting policies favored by the new administration.

The most straightforward crowding-out story starts from a fixed supply of private savings. These savings can either be lent to the government, or to business. The more the former takes, the less is left for the latter. But as Keynes pointed out long ago, this simple loanable-funds story assumes what it sets out to prove. The total quantity of saving is fixed only if total income is fixed. If higher government spending can in fact raise total income, it will raise total saving as well. We can only tell a story about government and business competing for a given pool of saving if we have already decided for some other reason that GDP can’t change.

The more sophisticated version, embodied in the textbook ISLM model, postulates a fixed supply of money, rather than saving. [1] In Hicks’ formulation, money is used both for transactions and as the maximally liquid store of wealth. The higher is output, the more money is needed for transactions, and the less is available to be held as wealth. By the familiar logic of supply and demand, this means that wealthholders must be paid more to part with their remaining stock of money. The price wealthholders receive to give up their money is interest; so as GDP rises, so does the interest rate.

Unlike the loanable funds story with fixed saving, this second story does give a logically coherent account of crowding out. In a world of commodity money, if such ever was, it might even be literally true. But in a world of bank-created credit money, it’s at best a metaphor. Is it a useful metaphor? That would require two things. First, that the interest rate (whichever one we are interested in) is set by the financial system. And second, that the process by which this happens causes rates to systematically rise with demand. The first premise is immediately rejected by the textbooks, which tell us that “the central bank sets the interest rate.” But we needn’t take this at face value. There are many interest rates, not just one, and the spreads between them vary quite a bit; logically it is possible that strong demand could lead to wider spreads, as banks stretch must their liquidity further to make more loans. But in reality, the opposite seems more likely. Government debt is a source of liquidity for private banks, not a use of it; lending more to the government makes it easier, not harder, for them to also lend more to private borrowers. Also, a booming economy is one in which business borrowers are more profitable; marginal borrowers look safer and are likely to get better terms. And rising inflation, obviously, reduces the real value of outstanding debt; however annoying this is to bankers, rationally it makes them more willing to lend more to their now less-indebted clients. Wicksell, the semi-acknowledged father of modern central banking theory, built his big book around the premise that in a credit-money system, inflation would give private banks no reason to raise interest rates.

And in fact this is what we see. Interest rate spreads are narrow in booms; they widen in crises and remain wide in downturns.

So crowding out mark two, the ISLM version, requires us to accept both that central banks cannot control the economically relevant interest rates, and that private banks systematically raise interest rates when times are good. Again, in a strict gold standard world there might something to this — banks have to raise rates, their gold reserves are running low — but if we ever lived in that world it was 150 or 200 years ago or more.

A more natural interpretation of the claim that the economy is at potential, is that any further increase in demand would just lead to inflation. This is the version of crowding out in better textbooks, and also the version used by MMT folks. On a certain level, it’s obviously correct. Suppose the amount of money-spending in an economy increases. Then either the quantity of goods and services increases, or their prices do. There is no third option: The total percent increase in money spending, must equal the sum of the percent increase in “real” output and the percent increase in average prices. But how does the balance between higher output and higher prices play out in real life? One possibility is that potential output is a hard line: each dollar of spending up to there increases real output one for one, and leaves prices unchanged; each dollar of spending above there increases prices one for one and leaves output unchanged. Alternatively, we might imagine a smooth curve where as spending increases, a higher fraction of each marginal dollar translates into higher prices rather than higher output. [2] This is certainly more realistic, but it invites the question of which point exactly on this curve we call “potential”. And it awakens the great bane of postwar macro – an inflation-output tradeoff, where the respective costs and benefits must be assessed politically.

Crowding out mark three, the inflation version, is definitely right in some sense — you can’t produce more concrete use values without limit simply by increasing the quantity of money borrowed by the government (or some other entity). But we have to ask first, positively, when we will see this inflation, and second, normatively, how we value lower inflation vs higher output and income.

In the post-1980s orthodoxy, we as society are never supposed to face these questions. They are settled for us by the central bank. This is the fourth, and probably most politically salient, version of crowding out: higher government spending will cause the central bank to raise interest rates. This is the practical content of the textbook story, and in fact newer textbooks replace the LM curve — where the interest rate is in some sense endogenous — with a straight line at whatever interest rate is chosen by the central bank. In the more sophisticated textbooks, this becomes a central bank reaction function — the central bank’s actions change from being policy choices, to a fundamental law of the economic universe. The master parable for this story is the 1990s, when the Clinton administration came in with big plans for stimulus, only to be slapped down by Alan Greenspan, who warned that any increase in public spending would be offset by a contractionary shift by the federal reserve. But once Clinton made the walk to Canossa and embraced deficit reduction, Greenspan’s fed rewarded him with low rates, substituting private investment in equal measure for the foregone public spending. In the current contest, this means: Any increase in federal borrowing will be offset one for one by a fall in private investment — because the Fed will raise rates enough to make it happen.

This story is crowding out mark four. It depends, first, on what the central bank reaction function actually is — how confident are we that monetary policy will respond in a direct, predictable way to changes in the federal budget balance or to shifts in demand? (The more attention we pay to how the monetary sausage gets made, the less confident we are likely to be.) And second, on whether the central bank really has the power to reliably offset shifts in fiscal policy. In the textbooks this is taken for granted but there are reasons for doubt. It’s also not clear why the actions of the central bank should be described as crowding out by fiscal policy. The central bank’s policy rule is not a law of nature. Unless there is some other reason to think expansionary policy can’t work, it’s not much of an argument to say the Fed won’t allow it. We end up with something like: “Why can’t we have deficit-financed nice things?” “Because the economy is at potential – any more public spending will just crowd out private spending.” “How will it be crowded out exactly?” “Interest rates will rise.” “Why will they rise?” “Because the federal reserve will tighten.” “Why will they tighten?” “Because the economy is at potential.”

Suppose we take the central bank out of the picture. Suppose we allow supply constraints to bind on their own, instead of being anticipated by the central planners at the Fed. What would happen as demand pushed up against the limits of productive capacity? One answer, again, is rising inflation. But we shouldn’t expect prices to all rise in lockstep. Supply constraints don’t mean that production growth halts at once; rather, bottlenecks develop in specific areas. So we should expect inflation to begin with rising prices for inputs in inelastic supply — land, oil, above all labor. Textbook models typically include a Phillips curve, with low unemployment leading to rising wages, which in turn are passed on to higher prices.

But why should they be passed on completely? It’s easy to imagine reasons why prices don’t respond fully or immediately to changes in wages. In which case, as I’ve discussed before, rising wages will result in an increase in the wage share. Some people will object that such effects can only be temporary. I’m not sure this makes sense — why shouldn’t labor, like anything else, be relatively more expensive in a world where it is relatively more scarce? But even if you think that over the long-term the wage share is entirely set on the supply side, the transition from one “fundamental” wage share to another still has to involve a period of wages rising faster or slower than productivity growth — which in a Phillips curve world, means a period above or below full employment.

We don’t hear as much about the labor share as the fundamental supply constraint, compared with savings, inflation or interest rates. But it comes right out of the logic of standard models. To get to crowding out mark five, though, we have to take one more step. We have to also postulate that demand in the economy is profit-led — that a distributional shift from profits toward wages reduces desired investment by more than it increases desired consumption. Whether (or which) real economies display wage-led or profit-led demand is a subject of vigorous debate in heterodox macro. But there’s no need to adjudicate that now. Right now I’m just interested in what crowding out could possibly mean.

Demand can affect distribution only if wage increases are not fully passed on to prices. One reason this might happen is that in an open economy, businesses lack pricing power; if they try to pass on increased costs, they’ll lose market share to imports. Follow that logic to its endpoint and there are no supply constraints — any increase in spending that can’t be satisfied by domestic production is met by imports instead. For an ideal small, open economy potential output is no more relevant than the grocery store’s inventory is for an individual household when we go shopping. Instead, like the household, the small open economy faces a budget constraint or a financing constraint — how much it can buy depends on how much it can pay for.

Needless to say, we needn’t go to that extreme to imagine a binding external constraint. It’s quite reasonable to suppose that, thanks to dependence on imported inputs and/or demand for imported consumption goods, output can’t rise without higher imports. And a country may well run out of foreign exchange before it runs out of domestic savings, finance or productive capacity. This is the idea behind multiple gap models in development economics, or balance of payments constrained growth. It also seems like the direction orthodoxy is heading in the eurozone, where competitiveness is bidding to replace inflation as the overriding concern of macro policy.

Crowding out mark six says that any increase in demand from the government sector will absorb scarce foreign exchange that will no longer be available to private sector. How relevant it is depends on how inelastic import demand is, the extent to which the country as a whole faces a binding budget or credit constraint and, what concrete form that constraint faces — what actually happens if international creditors are stiffed, or worry they might be? But the general logic is that higher spending will lead to a higher trade deficit, which at some point can no longer be financed.

So now we have six forms of crowding out:

1. Government competes with business for fixed saving.

2. Government competes with business for scarce liquidity.

3. Increased spending would lead to higher inflation.

4. Increased spending would cause the central bank to raise interest rates.

5. Overfull employment would lead to overfast wage increases.

6. Increased spending would lead to a higher trade deficit.

The next question is: Is there any reason, even in principle, to worry about any of these outcomes in the US today? We can decisively set aside the first, which is logically incoherent, and confidently set aside the second, which doesn’t fit a credit-money economy in which government liabilities are the most liquid asset. But the other four certainly could, in principle, reflect real limits on expansionary policy. The question is: In the US in 2017, are higher inflation, higher interest rates, higher wages or a weaker balance of payments position problems we need to worry about? Are they even problems at all?

First, higher inflation. This is the most natural place to look for the costs of demand pushing up against capacity limits. In some situations you’d want to ask how much inflation, exactly, would come from erring on the side of overexpansion, and how costly that higher inflation would be against the benefits of lower unemployment. But we don’t have to ask that question right now, because inflation is by conventional measures, too low; so higher inflation isn’t a cost of expansionary policy, but an additional benefit. The problem is even worse for Krugman, who has been calling for years now for a higher inflation target, usually 4 percent. You can’t support higher inflation without supporting the concrete action needed to bring it about, namely, a period of aggregate spending in excess of potential. [2] Now you might say that changing the inflation target is the responsibility of the Fed, not the fiscal authorities. But even leaving aside the question of democratic accountability, it’s hard to take this response seriously when we’ve spent the last eight years watching the Fed miss its existing target; setting a new higher target isn’t going to make a difference unless something else happens to raise demand. I just don’t see how you can write “What do we want? Four percent! When do we want it? Now!” and then turn around and object to expansionary fiscal policy on the grounds that it might be inflationary.

OK, but what if the Fed does raise rates in response to any increase in the federal budget deficit, as many observers expect? Again, if you think that more expansionary policy is otherwise desirable, it would seem that your problem here is with the Fed. But set that aside, and assume our choice is between a baseline 2018-2020, and an alternative with the same GDP but with higher budget deficits and higher interest rates. (This is the worst case for crowding out.) Which do we prefer? In the old days, the low-deficit, low-interest world would have been the only respectable choice: Private investment is obviously preferable to whatever government deficits might finance. (And to be fair, in the actual 2018-2020, they will mostly be financing high-end tax cuts.) But as Brad DeLong points out, the calculation is different today. Higher interest rates are now a blessing, not a curse, because they create more running room for the Fed to respond to a downturn. [3] In the second scenario, there will be some help from conventional monetary policy in the next recession, for whatever it’s worth; in the first scenario there will be no help at all. And one thing we’ve surely learned since 2008 is the costs of cyclical downturns are much larger than previously believed. So here again, what is traditionally considered a costs of pushing past supply constraints turns out on closer examination to be a benefit.

Third, the danger of more expansionary policy is that it will lead to a rise in the wage share. You don’t hear this one as much. I’ve suggested elsewhere that something like this may often motivate actual central bank decisions to tighten. Presumably it’s not what someone like Krugman is thinking about. But regardless of what’s in people’s heads, there’s a serious problem here for the crowding-out position. Let’s say that we believe, as both common sense and the textbooks tells us, that the rate of wage growth depends on the level of unemployment. Suppose we define full employment in the conventional way as the level of unemployment that leads to nominal wage growth just equal to productivity growth plus the central bank’s inflation target. Then by definition, any increase in the wage share requires a period of overfull employment — of unemployment below the full employment level. This holds even if you think the labor share in the long run is entirely technologically determined. A forteori it holds if you think that the wage share is in some sense political, the result of the balance of forces between labor and capital.

Again, I’m simply baffled how someone can believe at the same time that the rising share of capital in national income is a problem, and that there is no space for expansionary policy once full employment is reached. [4] Especially since the unemployment target is missed so often from the other side. If you have periods of excessively high unemployment but no periods of excessively low unemployment, you get a kind of ratchet effect where the labor share can only go down, never up. I think this sort of cognitive dissonance happens because economics training puts aggregate demand in one box and income distribution in another. But this sort of hermetic separation isn’t really sustainable. The wage share can only be higher in the long run if there is some short-run period in which it rises.

Finally, the external constraint. It is probably true that more expansionary fiscal policy will lead to bigger trade deficits. But this only counts as crowding out if those deficits are in some sense unsustainable. Is this the case for the US? There are a lot of complexities here but the key point is that almost all our foreign liabilities (and all of the government’s) are denominated in dollars, and almost all our imports are invoiced in dollars. Personally, I think the world is still more likely to encounter a scarcity of dollar liquidity than a surfeit, so the problem of an external constraint doesn’t even arise. But let’s say I’m wrong and we get the worst-case scenario where the world is no longer willing to hold more dollar liabilities. What happens? Well, the value of the dollar falls. At a stroke, US foreign liabilities decline relative to foreign assets (which are almost all denominated in their home currencies), improving the US net international investment position; and US exports get cheaper for the rest of the world, improving US competitiveness. The problem solves itself.

Imagine a corporation with no liabilities except its stock, and that also paid all its employers and supplies in its own stock and sold its goods for its own stock. How could this business go bankrupt? Any bad news would instantly mean its debts were reduced and its goods became cheaper relative to its competitors’. The US is in a similar position internationally. And if you think that over the medium term the US should be improving its trade balance then, again, this cost of over-expansionary policy looks like a benefit — by driving down the value of the dollar, “irresponsible” policy will set the stage for a more sustainable recovery. The funny thing is that in other contexts Krugman understands this perfectly.

So as far as I can tell, even if we accept that the US economy has reached potential output/full employment, none of the costs for crossing this line are really costs today. Perhaps I’m wrong, perhaps I’m missing something. but it really is incumbent on anyone who argues there’s no space for further expansionary policy to explain what concretely would be the results of overshooting.

In short: When we ask how close the economy is to potential output, full employment or supply constraints, this is not just a factual question. We have to think carefully about what these terms mean, and whether they have the significance we’re used to in today’s conditions. This post has been more about Krugman than I intended, or than he deserves. A very large swathe of established opinion shares the view that the economy is close to potential in some sense, and that this is a serious objection to any policy that raises demand. What I’d like to ask anyone who thinks this is: Do you think higher inflation, a higher “natural” interest rate, a higher wage share or a weaker dollar would be bad things right now? And if not, what exactly is the supply constraint you are worried about?

[1] The LM in ISLM stands for liquidity-money. It’s supposed to be the combination of interest rates and output levels at which the demand for liquidity is satisfied by a given stock of money.

[2] OK, some people might say the Fed could bring about higher inflation just by announcing a different target. But they’re not who I’m arguing with here.

[3] Krugman himself says he’d “be a lot more comfortable … if interest rates were well clear of the ZLB.” How is that supposed to happen unless something else pushes demand above the full employment level at current rates?

[4] It would of course be defensible to say that the downward redistribution from lower unemployment would be outweighed by the upward redistribution from the package of tax cuts and featherbedding that delivered it. But that’s different from saying that a more expansionary stance is wrong in principle.

What Do People Need to Know About International Trade?

On the first day of my trade class, we read Paul Krugman’s article “What Do Undergrads Need to Know About Trade?” In an admirably succinct four pages, it captures all the important things that orthodox trade theory claims to tell us about trade policy. I don’t think orthodox views on trade policy have changed at all in the 20 years since it was written. [1]

So what’s Krugman’s answer? What undergrads need to know, he says, is just what Hume and Ricardo were saying, 200 years ago: If relative costs of production are different in two countries, then total world output, and consumption in each individual country, will always be greater with trade than without, and prices will adjust so that trade is balanced. Free trade is always beneficial for all countries involved.

Krugman’s additions to this Ricardo-Hume catechism are mostly negative — a list of things we don’t need to talk about when talk about trade.

Don’t worry about development. The idea that a country can benefit from changing the sectors or industries it specializes in is, he says “a silly concept.” Yes, we look around the world and see workers in rich countries producing things like airplanes and software, which are worth a lot, and workers in poor countries putting the same effort into producing agricultural goods and textiles, which are worth much less. But

Does this mean the rich country’s high standard of living the result of being in the right sector, or that the poorer country would be richer if it tried to emulate the other’s pattern of specialization? Of course not.

Of course not. This blanket dismissal is rather odd, since the work Krugman won the Nobel for explicitly supports an affirmative answer to both questions. [2] It’s a case of esoteric versus exoteric knowledge, I guess — some truths are not meant for everyone. Or as Krugman delicately puts it, “the innovative stuff is not a priority for undergrads.”

Don’t worry about demand. In debates over policy, “the central issue is employment” in the arguments on both sides. But this is wrong, he says:

The level of employment is a macroeconomic issue, depending in the short run on aggregate demand and depending in the long run on the natural rate of unemployment, with policies like tariffs having little net effect. Trade policy should be debated in terms of its impact on efficiency…

It’s not immediately obvious why the claim that employment depends on aggregate demand is inconsistent with the claim that trade flows have important employment effects. After all, net exports are a component of demand. The implicit assumption is evidently that the central bank (or some other domestic policymaker) is maintaining the level of demand at the full-employment level, and will offset any effects from trade. [3]

Don’t worry about trade deficits, and the financing they require. “The essential things to teach students are still the insights of Ricardo and Hume. That is, trade deficits are self-correcting…”

The whole piece is frankly polemical — it’s clear that the goal is not to educate in the normal sense, but to equip students to take a particular side in public debates. This is not specific to Krugman, of course. If anything, most contemporary textbooks are even worse. [4] One reason I am using Caves and Frankel in my class is that it has less obnoxious editorializing than other texts I looked at. But less is still a lot.

Enough Krugman-bashing. What’s the alternative? What should people know about international trade? Matias Vernengo has one good alternative list. Here is mine.

There are three frameworks or perspectives in which we can productively think about international trade. The questions we ask in each case will depend on whether we are thinking of trade flows as the adjusting variable, or as reflecting an exogenous change to which some other variable(s) must adjust.

1. Trade flows are part of aggregate expenditure. On the one hand, a good way to predict trade flows is to assume that a fixed fraction of each dollar of spending goes to imported goods. As Joan Robinson and others have stressed, in the short run at least, adjustment of trade balances comes mainly or entirely through income changes. (This is also the perspective developed in Enno Schroeder’s work, which I’ve discussed here before.) On the other hand, if we can’t assume there is some level of full employment or potential output to which to which the economy always returns, then we have to be concerned with trade flows as one factor determining the level of aggregate income. This might be only a short-run phenomenon, as in mainstream Keynesian analysis, or it might be important to economic growth rates over the long run, as in models of balance of payments constrained growth.

2. Trade flows are part of the balance of payments. In a capitalist world economy, there are many different money payments and obligations between countries, of which trade flows are just part. In a world of liquidity constraints, certain configurations of money payments or money commitments are costly, or cannot be achieved at all. That is, a country in the aggregate cannot in general borrow unlimited amounts at “the” world interest rate. The tighter the constraints on a country’s financial position, the more positive a trade balance it must somehow achieve. On the other hand, for a given level of financing constraint, a more positive trade balance allows for more freedom on other dimensions. This interaction between trade flows and financial constraints is central to the balance of payments crises that are such a prominent feature of the modern world economy.

3. Trade flows involve specialization. Thinking now in terms of baskets of goods rather than money flows, the essential thing about international trade is that it allows a country’s consumption and production decisions to be made independently. Given that productive capacities vary more between countries than the mix of consumption goods chosen at a given income and prices, in practice this means that trade allows for specialization in production. If we take productive capacities as given, it follows that trade raises world output and income by allowing countries to specialize according to comparative costs. This is the essential (and genuine) insight of Ricardo. On the other hand, if we think that inherent differences between countries are small and that differences in productive capacity arise mainly through production itself, then international trade will lead to a historically contingent pattern of international specialization in which some positions are more advantageous than others. If causality runs from trade patterns to productive capacities and not just vice versa, then there is a case for including activity trade policy in any development strategy.

The orthodox trade theory has legitimate value and deserves a place in the curriculum. As we’ll discuss in the next post, simple textbook models of the Ricardo-Mill type can be used to tell stories with more interesting political implications than the usual free-trade morality tales. But they are only part of the picture. Much of what matters about trade depends on the fact that it involves flows of money and not just exchanges of goods.

[1] Have Krugman’s views changed since he wrote this? As reflected in his textbooks, no they have not. As reflected in his blog, seems like sometimes yes, sometimes no. Someone should ask him.

[2] For example, one of Krugman’s more widely cited articles is this one, which develops a model in which an innovating region (“the North”) develops new products, which it exports to a non-innovating region (“The South”). In the model,

Higher Northern per capita income depends on the quasi-rents from the Northern monopoly of new products, so the North must continually innovate not only to maintain its relative position but even to maintain its real income in absolute terms.

This is hard to distinguish from the arguments for industrial policy that Krugman dismisses as silly.

[3] What’s especially odd here is that orthodox theory says that in a world of mobile capital, the only tool the central bank has to maintain full employment is changes in the exchange rate. In standard textbooks (including Krugman’s own), it is impossible for monetary policy to boost employment unless it improves the trade balance.

[4] For example, David Colander’s generally undogmatic intro textbook includes a section titled “If trade is so good, why do so many people oppose it?”The answer turns out to be, they’re just confused.

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.

A Greek Myth

Most days, I’m a big fan of Paul Krugman’s columns.

Unlike his economics, which makes a few too many curtsies to orthodoxy, his political interventions are righteous in tone, right-on in content, and what’s more, strategic — unlike many leftish intellectuals, he clearly cares about being useful — about saying things that are not only true, but that contribute to the concrete political struggle of the moment. He’s so much better than almost of his peers it’s not even funny.

But — well, you knew there had to be a but.

But this time, he’s gotten his economics in his politics. And the results are not pretty.

In today’s column, he rightly dismisses arguments that the root of the Euro crisis is that workers in Greece and the other peripheral countries are lazy, or unproductive, or that those countries have excessive regulation and bloated welfare states. “So how did Greece get into so much trouble?” he asks. His answer:

Blame the euro. Fifteen years ago Greece was no paradise, but it wasn’t in crisis either. Unemployment was high but not catastrophic, and the nation more or less paid its way on world markets, earning enough from exports, tourism, shipping and other sources to more or less pay for its imports. Then Greece joined the euro, and a terrible thing happened: people started believing that it was a safe place to invest. Foreign money poured into Greece, some but not all of it financing government deficits; the economy boomed; inflation rose; and Greece became increasingly uncompetitive.

I’m sorry, but the bolded sentence just is not true. The rest of it is debatable, but that sentence is flat-out false. And it matters.

The analysis behind the “earning enough” claim is found on Krugman’s blog. He writes,

One of the things you keep hearing about Greece is that if it exits the euro one way or another there will be no gains, because Greece basically can’t export — so structural reform is the only way forward. But here’s the thing: if that were true, how did Greece pay its way before the big capital flows starting coming? The truth is that before the euro and the capital flow bubble it created, Greece ran only small current account deficits (the broad definition of the trade balance, including services and factor income)…

And he offers this graph from Eurostat:

The numbers in the graph are fine, as far as they go. And there is the first problem: how far they go. Here’s the same graph, but going back to 1980.

Starting the graph ten years earlier gives a different picture — now it seems that the near-balance on current account in 1993 and 1994 wasn’t the normal state before the euro, but an exceptional occurrence in just those two years. And note that that while Greek deficits in the 1980s are small relative to those of the mid-2000s, they are still very far from anything you could reasonably describe as “the country more or less paid its way.” They are, for instance, significantly larger than the contemporaneous US current account deficits that were a central political concern in the 1980s here.

That’s the small problem; there’s a bigger one. Because, what are we looking at? The current account balance. Krugman glosses this as “the broadest measure of the trade balance,” but that’s not correct. (If he taught undergraduate macro, I’m sure he’d mark someone writing that wrong.) It’s broad, yes, but it’s a different concept, covering all international payments other than asset purchases, including some (transfers and income flows) that are not trade by any possible definition. The current account includes, for example, remittances by foreign workers to their home countries. So by Krugman’s logic here, the fact that there are lots of Mexican migrant workers in the US sending money home is a sign that Mexico is able to export successfully to the US, when in the real world it’s precisely a sign that it isn’t.

Most seriously, the current account includes transfer between governments. In the European context these are quite large. To call the subsidies that Greece received under the European Common Agricultural Policy export earnings is obviously absurd. Yet that’s what Krugman is doing.

The following graph shows how big a difference it makes when you call development assistance exports.

The blue line is the current account balance, same as in Krugman’s graph, again extended back to 1980. The red line is the current account balance not counting intergovernmental transfers. And the green line is the current account not counting any transfers. [*] It’s clear from this picture that, contra Krugman, Greece was not earning enough money to pay for its imports before the creation of the euro, or at any time in the past 30 years. If the problem Greece has to solve is getting its foreign exchange payments in line with with its foreign exchange earnings, then the bulk of the problem existed long before Greece joined the euro. The central claim of the column is simply false.

Again, it is true that Greece’s deficits got much bigger in the mid-2000s. I agree with Krugman that this must have ben connected with the large capital flows from northern to peripheral Europe that followed the creation of the euro. It remains an open question, though, how much this was due to an increase in relative costs, and how much due to more rapid income growth. By assuming it was entirely the former, Krugman is implicitly, but characteristically, assuming that except in special circumstances economies can be assumed to be operating at full capacity.

But the key point is that the historical evidence does not support the view that current account imbalances only arise when governments interfere in the natural adjustment of foreign exchange markets. Fixed rates or floating, in the absence of very large flows of intergovernmental aid Greece has never come close to current account balance. According to Krugman, Greece’s

famous lack of competitiveness is a recent development, caused by massive post-euro inflows of capital that raised costs and prices. And that’s the kind of thing that currency devaluations can cure.

The historical evidence is not consistent with this claim. Or if it is, it’s only after you go well beyond normal massaging of the data, to something you’d see on The Client List.

* * *

So why does it matter? What’s at stake? I can’t very well go praising Krugman for writing not only what’s true but what is useful, and then justify a post criticizing him on the grounds of Someone Is Wrong On the Internet. No; but there’s something real at stake here.

The basic issue is, does price adjustment solve everything? Krugman won’t quite come out and say Yes, but clearly it’s what he believes. Is he being deliberately dishonest? No, I’m sure he’s not. But this is how ideology works. He’s committed to the idea that relative costs are the fundamental story when it comes to trade, so when he finds a bit of data that seems to conform to that, he repeats it, without giving five minutes of critical reflection to what it actually means.

The basic issue, again, is the need for structural as opposed to price adjustment. Now if “structural adjustment” means lower wages, then of course Godspeed to Krugman here. I’m against structural whatever in that sense too. But I can’t help feeling that he’s pulling in the wrong direction. Because if external devaluation cures the problem then internal devaluation does too, at least in principle.

The fundamental question remains how important are relative costs. The way I see it, look at what Greece imports, most of it Greece doesn’t produce at all. The textbook expenditure-switching vision implicitly endorsed by Krugman ignores that there are different kinds of goods, or accepts what Paul Davidson calls the axiom of gross substitution, that every good is basically (convexly) interchangeable with every other. Hey Greeks will have fewer computers and no oil, but they’ll spend more time at the beach, and in terms of utility it’s all the same. Except, you know, it’s not.

From where I’m sitting, the only way for Greece to achieve current account balance with income growth comparable to Germany is for Greece to develop new industries. This, not low wages, is the structural problem. This is the same problem faced by any developing country. And it raises the same problem that Krugman, I’m afraid, has never dealt with: how to you convince or compel the stratum that controls the social surplus to commit to the development of new industries? In the textbook world — which Krugman I’m afraid still occupies — a generic financial system channels savings to the highest-return available investment projects. In the real world, not so much. Figuring out how to get savings to investment is, on the contrary, an immensely challenging institutional problem.

So, first step dealing with it, you should read Gerschenkron. We know, anyway that probably the rich prefer to hold their wealth in liquid form, or overseas, or both. And we know that even if — unlikely — they want to invest in domestic industries, they’ll choose those that are already cost-competitive, when, we know, the whole point of development is to do stuff where you don’t, right now, have comparative advantage. So, again, it’s a problem.

There are solutions to this problem. Banks, the developmental state, even industrial dynasties. But it is a problem, and it needs to be solved. Relative prices are second order. Or so it seems to me.

[*] Unfortunately Eurostat doesn’t seem to have data breaking down nongovernmental transfer payments to Greece. I suspect that the main form of private transfers is remittances from Greek workers elsewhere in Europe, but perhaps not.