Tag: capital controversies

Piketty Post at Crooked Timber

Crooked Timber is having a book event on Piketty’s Capital in the 21st Century. My contribution is here. A few supplemental bits:

First, I need to point out a problem in my post. I write: “It’s striking, for instance, that the book does not contain a table or figure comparing r and g historically.” But of course, as David Rosnick points out in email, this is not true. There are three figures in chapter 10 that purport to give historical values for r and g. The inadequacy of these figures to bear the weight put on the r > g apparatus is, I think, evident. Why are there no cross-country comparisons? Why the odd periodizations? Why so much emphasis on the data-free values invented for the distant past and future? Perhaps most damningly, what about the fact that r > g is no more true in the increasingly unequal second half of the 20th century than in the increasingly equal first half? But none of that changes the fact that my sentence, as I wrote it, is wrong.

Some people may be interested in other things I’ve written relating to Piketty on this blog over the past couple years:

A Quick Point on Models

Posts in Three Lines

Piketty and the Money View: A Reply to MisterMR

Piketty and the Money View

Wealth Distribution and the Puzzle of Germany

Mehrling on Black on Capital

Three Ways of Looking at alpha = r k

With respect to the Crooked Timber piece, I should say — should have acknowledged in the post itself — that it all comes out of conversations I’ve been having with Suresh Naidu over the past year or so. Suresh himself has written various things about Piketty; he’s working on a piece now on these same themes of capital, Piketty and the money view that should move the conversation significantly forward.

I should also have pointed out the Real World Economic Review’s superb special issue on Piketty. Jamie Galbraith’s, Merijn Knibbe’s, and Yanis Varoufakis’ contributions made many of the same points I tried to make in the Crooked Timber post. Knibbe’s piece in particular is a tour de force, everyone interested in these debates should read it.

Finally, I should say: I’ve been reading Crooked Timber since it began, in 2003. For a long while I was a regular commenter there, most of that time pseudonymously as Lemuel Pitkin. Now twelve years is a long time in internet time. Not so long in real life but still long enough  for me to go back to graduate school, get my PhD and various teaching jobs, and to start this blog. Crooked Timber was probably my main inspiration to try to write in this format. So I can’t deny it, I’m thrilled to finally have a post up there.

 

 

A Quick Point on Models

According to Keynes the purpose of economics is “to provide ourselves with an organised and orderly method of thinking out particular problems”; it is “a way of thinking … in terms of models joined to the art of choosing models which are relevant to the contemporary world.” (Quoted here.)

I want to amplify on that just a bit. The test of a good model is not whether it corresponds to the true underlying structure of the world, but whether it usefully captures some of the regularities in the concrete phenomena we observe. There are lots of different regularities, more or less bounded in time, space and other dimensions, so we are going to need lots of different models, depending on the questions we are asking and the setting we are asking them in. Thus the need for the “art of choosing”.

I don’t think this point is controversial in the abstract. But people often lose sight of it. Obvious case: Piketty and “capital”. A lot of the debate between Piketty and his critics on the left has focused on whether there really is, in some sense, a physical quantity of capital, or not. I don’t think we need to have this argument.

We observe “capital” as a set of money claims, whose aggregate value varies in relation to other observable monetary aggregates (like income) over time and across space. There is a component of that variation that corresponds to the behavior of a physical stock — increasing based on identifiable inflows (investment) and decreasing based on identifiable outflows (depreciation). Insofar as we are interested in that component of the observed variation, we can describe it using models of capital as a physical stock. The remaining components (the “residual” from the point of view of a model of physical K) will require a different set of models or stories. So the question is not, is there such a thing as a physical capital stock? It’s not even, is it in general useful to think about capital as a physical stock? The question is, how much of the particular variation we are interested is accounted for by the component corresponding to the evolution of a physical stock? And the answer will depend on which variation we are interested in.

For example, Piketty could say “It’s true that my model, which treats K as a physical stock, does not explain much of the historical variation in capital-output ratios at decadal frequencies, like the fall and rise over the course of the 20th century. But I believe it does explain very long-frequency variation, and in particular captures important long-run possibilities for the future.” (I think he has in fact said something like this, though I can’t find the quote at the moment.) You don’t have to agree with him — you could dispute that his model is a good fit for even the longest-frequency historical variation, or you could argue that the shorter frequency variation is more interesting (and is what his book often seems to be about). But it would be pointless to criticize him on the grounds that there isn’t “really” such a thing as a physical capital stock, or that there is no consistent way in principle to measure it. That, to me, would show a basic misunderstanding of what models are.

An example of good scientific practice along these lines is biologists’ habit of giving genes names for what happens when gross mutations are induced in them experimentally. Names like eyeless or shaggy or buttonhead: the fly lacks eyes, grows extra hair, or has a head without segments if the gene is removed. It might seem weird to describe genes in terms of what goes wrong when they are removed, as opposed to what they do normally, but I think this practice shows good judgement about what we do and don’t know. In particular, it avoids any claim about what the gene is “for.” There are many many relationships between a given locus in the genome and the phenotype, and no sense in which any of them is more or less important in an absolute sense. Calling it the “eye gene” would obscure that, make it sound like this is the relationship that exists out in the world, when for all we know the variation in eye development in wild populations is driven by variation in entirely other locuses. Calling it eyeless makes it clear that it’s referring to what you observe in a particular experimental context.

EDIT: I hate discussions of methodology. I should not have written this post. (I only did because I liked the gene-naming analogy.)  That said, if you, unlike me, enjoy this sort of thing, Tom Hickey wrote a long and thoughtful response to it. He mentions among others, Tony Lawson, who I would certainly want to read more of if I were going to write about this stuff.

Piketty and the Money View: A Reply to MisterMR

The last post got some very helpful comments from MisterMR (the regular commenter formerly known as Random Lurker) and Kevin Donoghue. Both of them raise issues that are worth posts of their own. I’ll reply to MisterMR now, and perhaps to Kevin Donoghue later. Or perhaps not — the biggest thing I’ve learned in four years of blogging is: Never make promises about future posts.

* * *

MisterMR is coming from what I hope he won’t mind my calling a classical Marxian perspective — a perspective I’m simpatico with, tho I haven’t been taking it here. One aspect of this perspective is the idea that capital can be understood in physical terms, as embodied labor. Now I agree that Marx does clearly say this, but I think this can be seen as a concession he is making to the orthodoxy of the day for the sake of the argument. Capital is subtitled “A Critique of Political Economy,” and I think we should take that subtitle seriously. In effect, he is saying to Ricardo: OK, let’s accept your way of thinking about capital, the system based on it is still conflictual, exploitative and in contradiction with its own conditions of existence.

I’m not sure how widely this view is held — that Marx adopts the labor theory of value ironically. Anyway, that’s not the argument I want to have here. What I want to do is clarify the perspective I’m offering in place of the labor theory. It’s more in the spirit of the other core Marxian idea about capital, that it is a social relation between people.

MisterMR writes:

I think that there are 4 different kinds of capital assets (though in reality most capital assets are a mix of the four kinds). 

1) There are some capital goods that are stuff that is materially produced, such as factories. This stuff has a cost of production, that arguably has some relationship with its “value”. This is what I would call “real” capital. The ambiguity in Piketty comes from the fact that he speaks as if all capital is “real” capital, and as if every money flow translates in “real” capital. 

2) There are some assets that are a finite resource that someone controls, like land. In fact, classical economists distinguished between “capital” and “land”. The value of land can’t be linked to the “cost of production” of land, because said cost doesn’t exist. So arguably the value is just the cashflow derived from the asset divided by the normal rate of profit. I’d call this kind of assets simply “land”. 

3) While land is certainly something that exists, there are some assets that have an economic value but that don’t relate to something that clearly exists or that can be produced: for example, ownership on patents, or a famous brand that has an high market penetration and visibility etc. I think that these assets have dinamics that are similar to land, although they are mostly non material. 

4) Finally, there is credit. Credit also is a non material thing, and is different from all the 3 previous classes of capital for these reasons: 

4.1) It doesn’t have a “cost of production”;
4.2) It isn’t related to any fixed resource, something that differentiates credit from both 2 and 3;
4.3) It has a fixed nominal value (which implies that the currency provider can literally print it out of existence).
4.4) It usually has a nominally fixed interest rate, something that can obviously cause chain bankruptcies. 

My problem with the “monetary view” is that it sounds like if assets of the 2 and 3 classes all are just a “montary” thing, as opposed to a “real stuff view” that sees all assets as if they were of the 1 class.

My response is that the money view is not a substantive claim about the nature of particular assets, but a way of looking at assets in general — “real” capital goods as much as the more vaporous claims in categories 2 through 4. It does imply some kind of ontology, but in itself, the money view is just a choice to focus on money payments.

But I do want to explain the broader view of social reality that, for me at least, lies behind the money view.  Here’s the way I want to look at things.

* * *

On the one hand, there is the human productive activity of collectively transforming the world and maintaining our conditions of existence, along with the conditions that make that activity possible. When you sit down and write a blog post, you are engaged in creative activity with the goal of building up our collective knowledge of the world, and you are also maintaining the network of social ties through which this kind of activity is carried out. Your ability to engage in this activity depends on a great number of objective conditions, ranging from your physical health to the infrastructure that communicates your words to the rest of the world. Many of these conditions are the result of past human activity.

Under capitalism, a subset of human productive activity gets marked off as “labor.” Labor has a number of special characteristics, most obviously that it is carried out at the direction of a boss. But for current purposes, the most important distinctive characteristics of the activity that we call “labor”  are (a) it carries a price tag, the “wage,” with labor that is somehow similar carrying a similar wage. And (b) labor becomes substantively more similar over time, with the disappearance of specific skills and increasing interchangeability among the human beings performing it; it follows from this that the wage also become uniform. To the extent that (a) is true, we can attribute a “cost” to some particular set of conditions and to the extent (b) is also true, that cost will correspond to the hours of labor expended maintaining those conditions. Of course all productive activity additionally requires many conditions, both natural and social, that are not reflected in labor hours. In particular, a great deal of passive social cooperation is required for any productive activity, especially when there is an extensive division of labor.

Even in the pure case, where labor is completely homogeneous and all production is carried out for profit, under identical conditions and with no barriers to competition, there will not in general be a unique mapping from labor hours to costs or relative prices. The best we can do is to reduce all the infinite possible sets of relative prices to variation along a single dimension, with one set of relative prices corresponding to each possible profit rate. (I think this is Sraffa’s point.)

So the description of assets in group 1 is correct — but only with respect to one particular way of describing one particular way of organizing production, not as statements about reality in general. The productive activity that takes place in a factory does, of course, require the past activity that resulted in the existence of the factory. But it requires lots of other activity as well, much of which is not counted as “labor.” And the fact that “labor” is a measurable input at all only holds to the extent that the productive activity has been deskilled and homogenized, a sociological fact that is never completely true and is not true at all in most historical contexts.

The think you have to avoid is believing that quantities like “value” or “cost” have any existence outside the specific social relations of capitalism.

The next question is what it means to “own” some conditions for productive activity, like a factory. The beginning of wisdom here is to recognize that ownership is a legal relationship between persons, not a relationship with a physical object. To own a piece of land means you have certain legal rights with respect to other people — to exclude them from the use of that land, to receive some equivalent from them if you do permit use of the land, to transfer those rights to someone else — and that no one else has those rights with respect to you. However, that’s only the first step. Next, we have to recognize that what constitutes “use” of piece of an asset is not a physical fact, but a social one. (As in the old story, the baker can exclude others from eating his rolls, but not from enjoying the smell of them.) So it would be more accurate to say that ownership of a piece of property is simply a form of social authority — a bundle of rights over other people. Indeed, if we want to relate the world of money flows to broader social reality, the most fundamental fact is probably this: The person who receives a money payment labeled “profit” gives orders, and the people who receive money payments labeled “wages” have to follow them. To say you own a piece of property is simply to say there is a set of commands that, if you issue them, other people are compelled to obey. Those rights are metonymously referred to by a label which bears a picture of some tangible good, just like the insignia on an officer’s uniform bear a picture of a leaf or a bird.

So:

When you say, here is a means of production, a factory, with a certain cost, you have already chosen: to ignore all the various conditions that make a certain form of collective productive activity possible, and let the existence of this one tangible object, the factory, stand in for all the rest; to ignore all the various forms of productive activity and social coordination that were necessary to bring the factory  (and the rest of the conditions of production) into existence, except for those we class as wage labor; to convert that wage labor to some common quantitative standard by measuring it in wage payments;  to assume some exogenously given profit rate, to give you the discount rate you need to add up wage payments made at different dates. Only then can you say the factory has a cost — and even then, this money cost is calculated by adding up a certain set of money payments.

At that point we have MisterMR’s category (1) as a concrete social reality. We still have to establish the profit rate, since it cannot be reduced to a marginal physical product. Only then do the issues specific to the other three categories come into play.

I should be clear: the money view is not a complete account of the sphere of social reality we call the economy. (And again, I’ve adopted the term from Perry Mehrling, it’s not my invention.) The money view is defined by making the atomic units of analysis bundles of money payments. I would argue that it is logically consistent to think of any capital good as simply a bundle of income streams contingent on different states of the world, in a way that it is not logically consistent to think of it as a physical object producing a stream of physical outputs.

The fact that this is a logically consistent account doesn’t mean it’s sufficient. Obviously the money view doesn’t give a complete story, since we don’t know why the income streams attached to different assets are what they are, or why they change over time, or why assets in the monetary sense are attached to tangible goods or production processes, or for that matter why anyone cares about money payments in the first place. But by adopting a consistent story about money payments and assets, we get a clearer view of these other questions. We distinguish the questions that can be addressed with the formal techniques of economics from other questions that require a different approach. This is a step forward from the perspective that mixes up questions about money flows with questions about tangible productive activities and so can’t give a coherent story about either.

Mehrling on Black on Capital

In a post last week, I suggested that an alternative to thinking of capital as quantity of means of production accumulated through past investment, is to think of it as the capitalized value of expected future profit flows. Instead of writing


α = r k

where α is the profit share of national income, r is the profit rate, and k is the capital-income ratio, we should write 
k = α / r
where r is now understood as the discount rate applied to future capital income. 
Are the two rs the same? Piketty says no: the discount rate is presumably (some) risk-free interest rate, while the return on capital is typically higher. But I’m not sure this position is logically sustainable. If there are no barriers to entry, why isn’t investment carried to the point where the return on capital falls to the interest rate? On the other hand, if there are barriers to entry, so that capital can continue to earn a return above the interest rate without being flooded by new investment with borrowed funds, then profits cannot all be attributed to measured capital; some is due to whatever privilege creates the barriers. Furthermore, in that case there will not be, even tendentially, a uniform economywide rate of profit. 
In any case, whether or not we have a coherent story of how there can be a profit rate distinct from the discount rate, it’s clearly the latter that matters for corporate equity, which is the main form of capital Piketty observes in modern economies. Verizon, to take an example at random, has current annual earnings of around $20 billion and is valued by the stock market at around $200 billion. Nobody, I hope, would interpret these numbers as meaning that Verizon has $200 billion of capital and, since the economy-wide profit rate is 10%, that capital generates $20 billion in profits. Rather, Verizon — the enterprise as a whole, its physical capital, its organization and corporate culture, its brand, its relationships with regulators, the skills and compliance (or not) of its workers — currently generates $20 billion a year of profits. And the markets — applying the economy-wide discount factor embodied in the interest rate, plus a judgement about the likely change in share of the social surplus Verizon will be able to claim in the future — assess the present value of that stream of profits from now til doomsday at $200 billion.  
Now it might so happen that the stock market capitalization of a corporation is close to the reported value of assets less liabilities — this corresponds to a Tobin’s q of 1. Verizon, with total assets of $225 billion and total liabilities of $50 billion, happens to fit this case fairly well. It might also be the case that a firm’s reported net assets, deflated by some appropriate price index, correspond to its accumulated investment; it might even also be the case that there is a stable relationship between reported net capital and earnings. But as far as market capitalization goes, it makes no difference if any of those things is true. All that matters is market expectations of future earnings, and the interest rate used to discount them.
I was thinking about this in relation to Piketty’s Capital in the 21st Century. But of course the point is hardly original. Fischer Black (of the Black-Scholes option-pricing formula) made a similar argument decades ago for thinking of capital as a claim on a discounted stream of future earnings, rather than as an accumulation of past investments. 
Here’s Perry Mehrling on Black’s view of capital:

As in Fisher, Black’s emphasis is on the market value of wealth calculated as the expected present value of future income flows, rather than on the quantity of wealth calculated as the historical accumulation of savings minus depreciation. This allows Black to treat knowledge and technology as forms of capital, since their expected effects are included when we measure capital at market value. As he says: “more effective capital is more capital” (1995a, 35). Also as in Fisher, capital grows over time without any restriction from fixed factors. 

… 

For Black, the standard aggregative neoclassical production function is inadequate because it obscures sectoral and temporal detail by attributing current output to current inputs of capital and labor, but he tries anyway to express his views in that framework in order to reach his intended audience. Most important, he accommodates the central idea of mismatch to the production function framework by introducing the idea that the “utilization” of physical capital and the “effort” of human capital can vary over time. This accommodation makes it possible to express his theory in the familiar Cobb-Douglas production function form: y = A(eh)^α(fk)^(1-α), where y is output, h and k are human and physical capital, e and f are effort and utilization, and A is a temporary shock (1995, eq. 5.3). 

It’s familiar math, but the meaning it expresses remains very far from familiar to the trained economist. For one, the labor input has been replaced by human capital so there is no fixed factor. For another, both physical and human capital are measured at market values, and so are supposed to include technological change. This means that the A coefficient is not the usual technology shift factor (the familiar “Solow residual”) but only a multiplier, indeed a kind of inverse price earnings ratio, that converts the stock of effective composite capital into a flow of composite output. In effect, and as he recognizes, Black’s production function is a reduced form, not a production function at all in the usual sense of a technical relation between inputs and outputs. What Black is after comes clearer when he groups terms and summarizes as Y=AEK (eq. 5.7), where Y is output, E is composite utilization, and K is composite capital. Here the effective capital stock is just a constant multiple of output, and vice versa. It’s just an aggregate version of Black’s conception of ideal accounting practice (1993c) wherein accountants at the level of the firm seek to report a measure of earnings that can be multiplied by a constant price- earnings ratio to get the value of the firm. 

… 

In retrospect, the most fundamental source of misunderstanding came (and comes still) from the difference between an economics and a finance vision of the nature of the economy. The classical economists habitually thought of the present as determined by the past. In Adam Smith, capital is an accumulation from the careful saving of past generations, and much of modern economics still retains this old idea of the essential scarcity of capital, and of the consequent virtue attached to parsimony. The financial point of view, by contrast, sees the present as determined by the future, or rather by our ideas about the future. Capital is less a thing than an idea about future income flows discounted back to the present, and the quantity of capital can therefore change without prior saving.

In comments, A H mentioned that Post Keynesian or structuralist economics seem much closer to the kind of analysis used by finance professionals than orthodox economics does. I think one reason is that we share what Mehrling calls the “money view” or, here, the “finance vision” of the economy. Orthodoxy sees the economy as a set of exchanges of goods; the finance vision sees  a set of contractual money payments. 
Mehrling continues:

In The Nature of Capital and Income, Irving Fisher (1906) straddled the older world view of economics and the emerging world view of finance by distinguishing physical capital goods (for which the past-determines-present view makes sense) from the value of those goods (for which the future-determines-present view makes sense). By following Fisher, Black wound up employing the same straddle. 

Piketty may be in a similarly awkward position.