The Passage of Time, Capital, and Investment in Traditional and in Recent Neoclassical Value Theory

New paper by Fabio Petri published in Œconomia. From the abstract:

With the shift from traditional analyses where capital is a single value factor of variable ‘form’ to the neo-Walrasian versions, general equilibrium theory has encountered new problems pointed out by P. Garegnani (1976, 1990): impermanence problem, price-change problem, substitutability problem radically question the right to consider neo-Walrasian equilibria as approximating the actual path of real economies. The paper briefly summarizes these problems and then concentrates on a fourth problem, the savings-investment problem, arguing that neo-Walrasian general equilibrium theory assumes that investment is adjusted to full-employment savings but cannot justify this assumption. The attempt to justify it in intertemporal general equilibrium through the tâtonnement is subjected to a new criticism: it is shown that the tâtonnement assumes Says’ Law all along the adjustments, and determines investment in a way that would crumble if it were not assumed that consumers determine their demands for consumption goods on the basis of an assumption of full employment incomes, which is not justified outside equilibrium, and was not assumed in traditional analyses. This reinforces the absence of reasons to view neo-Walrasian equilibrium paths as sufficiently approaching actual paths. It is concluded that behind the reference to intertemporal equilibrium as the microfoundation of macro analyses there is a continuing faith in traditional neoclassical time-consuming adjustment mechanisms, based on the old and untenable conception of capital that the shift to neo-Walrasian equilibria intended to do without.

Full paper available here.

Lars Syll on Loanable Funds Theory

By Lars Syll

The classical theory of the rate of interest [the loanable funds theory] seems to suppose that, if the demand curve for capital shifts or if the curve relating the rate of interest to the amounts saved out of a given income shifts or if both these curves shift, the new rate of interest will be given by the point of intersection of the new positions of the two curves. But this is a nonsense theory. For the assumption that income is constant is inconsistent with the assumption that these two curves can shift independently of one another. If either of them shift, then, in general, income will change; with the result that the whole schematism based on the assumption of a given income breaks down … In truth, the classical theory has not been alive to the relevance of changes in the level of income or to the possibility of the level of income being actually a function of the rate of the investment.

There are always (at least) two parts in an economic transaction. Savers and investors have different liquidity preferences and face different choices — and their interactions usually only take place intermediated by financial institutions. This, importantly, also means that there is no “direct and immediate” automatic interest mechanism at work in modern monetary economies. What this ultimately boils done to is — iter — that what happens at the microeconomic level — both in and out of equilibrium — is not always compatible with the macroeconomic outcome. The fallacy of composition has many faces — loanable funds is one of them.

Read the rest here.

On the state of macroeconomics: fashion versus logic and evidence

Yes there is something rotten in the kingdom of Denmark, and it is macroeconomics; pretty much as in every other country. There has been an ongoing debate on the blogosphere on the topic (see Krugman, Smith, Thoma, Williamson and Wren-Lewis, not in chronological order, by the way). The New Classical versus New Keynesian debate tends to be on two issues the relevance of microfoundations on the theoretical level, and the importance of price rigidities on the empirical side.

Scientists, as Mankiw put it, are the New Classicals that emphasize the microfundations. They have intertemporal maximization models based on rational representative agents. The New Keynesians are the engineers, again using Mankiw's dichotomy, that strive for economic realism. Or so is what you are expected to believe if you read their posts. Of course all of these presumptions are bogus.

Noah Smith correctly points out that they all use the same DSGE models. But Krugman notes that on policy debates the whole difference is based on the assumption of sticky prices. So they use the same models, but reach very different conclusions. Of course the tools are not neutral though. Using DSGE models has hurt the positions that New Keynesian want to take. For example, Krugman has been forced to argue that the reason for the poor recovery is that the natural rate of interest is negative (and hence the current rate is too high to bring investment and savings into equilibrium).

This is a much weaker position than the one taken by heterodox authors that suggest that the crisis is due to lack of demand associated to worsening income distribution over the last three decades, and the consequent expansion of unsustainable private debt to allow for consumption. So the poor recovery is associated to lack of demand, since wages are stagnant and private debt cannot increase (and the GOP is bent in not allowing public demand to grow).

Note that the Godley type models, which follow the heterodox perspective, were much better for understanding and foreseeing the crisis (see here). There is no reason for intertemporal maximization models, and their kind of microeconomics (Sraffians have better stuff for that). New Classicals, Mankiw notwithstanding, are not scientists (or at least not good ones), since their models do have significant logical problems, and you cannot be a good engineer, somebody concerned with practical applications of scientific knowledge, if you share a model that is flawed.

On an interesting note, Krugman's main complain about Noah Smith's position is that he doesn't understand that the New Classicals have basically treated New Keynesians as outcasts. In his words:

"the freshwater [New Classical] types simply didn’t accept the legitimacy of what the New Keynesians were doing — in fact, didn’t even bother to read any of it, because anyone who actually worked with that kind of model would know that fiscal policy can indeed have an effect in that framework."

The problem is that they don't think he is legitimate. In fact, that is true. Williamson says:

"It doesn't surprise me that Paul Krugman isn't up on what is going on in macroeconomic research. Why should we expect him to go to macro conferences, spend time in seminars, and talk to his colleagues at Princeton? He has plenty on his plate, what with delivering two NYT columns per week, blogging, talking to pundits, and giving speeches. But if he's not up on the field, what purpose does it serve to make up outlandish stuff for people to read?"

Indeed Williamson's critique is that Krugman is not up to date, on the cutting edge, Colander would say. So he has missed the last fashion season in macroeconomics. And Wren-Lewis makes a point that he is a Karl Lagerfeld of macroeconomics (not sure if that is a correct fashion quote). Wren-Lewis points out that:

PK [yes, Paul Krugman] was very much at the forefront of analysing the Zero Lower Bound problem, before that problem hit most of the world. While many point to Mike Woodford’s Jackson Hole paper as being the intellectual inspiration behind recent changes at the Fed, the technical analysis can be found in Eggertsson and Woodford, 2003. That paper’s introduction first mentions Keynes, and then Krugman’s 1998 paper on Japan. Subsequently we have Eggertsson and Krugman (2010), which is part of a flourishing research programme that adds ‘financial frictions’ into the New Keynesian model. You would not think of suggesting that PK is out of touch unless you are in effect dismissing or marginalising this whole line of research.

So he is pretty much au courant, according to his New Keynesian friends (and that sounds right to me too, by the way). No fashion problem with Krugman and New Keynesians. They are trendy too. Good for them.

Yet, what it is expected of science is not fashion, but relevance following logic and evidence. And yes Krugman is right, there is evidence for price rigidity, and also no evidence for the sort of theory of distribution implicit in the mainstream neoclassical DSGE models (productivity equals remuneration of factors of production), or for a natural rate for that matter. And that is the problem with Krugman and his New Keynesian friends, too much preoccupation with fashion, not enough with logic and evidence. If the profession remains concerned with fashionable models it will continue to be irrelevant and impractical.

Ramblings on 21st century macroeconomics

Guillermo Calvo wrote a post on what he thinks is the new macroeconomics. Minsky gets cited, but that's pretty much the only concession to heterodox macroeconomics. The interpretation of what the "new" macro for the 21st century should be is basically New Keynesian price/wage rigidities models cum debt-deflation (the finance and Minsky part). But even the understanding of debt-deflation is limited to the notion of sudden stops (slowdown or reversal of capital inflows).

According to him:

"many of us have been involved in developing and testing theories in which imperfections in financial markets play a central role – and coining new terms like Sudden Stop and Phoenix Miracles. The dominant view, however, was that financial crises in EMs reflected weak institutions in that part of the world, and could not possibly take place in advanced economies. Unfortunately, the subprime crisis revealed, to the dismay of many in advanced economies, especially in Europe, that the world is more uniform than we thought!"

In other words, he seems to think that market imperfections are pervasive and that developed countries are vulnerable to sudden stops, like emerging markets (a terrible name popularized in the 1990s for developing countries, as if the only thing were the 'markets'). Note that while developing countries have not experienced sudden stops with the financial crash of 2008, and have used international reserves to insure against the volatility of financial markets (and often introduced capital controls too, when those were not already in place), no significant sudden stop affected the US, the epicenter of the crisis.

As noted by several heterodox economists the crisis in the US the deep causes of the crisis were associated to wage stagnation (worsening income distribution) and the associated increase in private debt, which led to a collapse of spending in the aftermath of the Lehman crisis. Mind you, at that point capital flows went into Treasury bonds, and no sudden stop affected the American economy (in contrast to say Argentina in 2002). So no, the world is not flat or "more uniform" that Calvo thought.

Just for those that might not remember, on dollarization this is what Calvo (paper with Carmen Reinhart) used to say back in 2000 (a few years before the Argentinean crisis; he was rumored as a possible finance minister at the time in Argentina, and the notion was that he was for dollarization):

"Exchange rate movements are costly in this environment. If policymakers take a hard look at the options for exchange rate regimes in emerging economies, they may find that floating regimes may be more of an illusion and that fixed rates--particularly, full dollarization--might emerge as a sensible choice for some countries, especially in Latin America or in the transition economies in the periphery of Euroland."

The sensible choice was dollarization (sic)! Note that his point was that with sufficient fiscal austerity, credibility would be restored, and capital would flow in the right direction (if you are from Greece, you should be afraid if this is the 'new' macro).

But back to sudden stops, which is the basis of his claim to have introduced financial markets into modern macro, here is what he had to say in his post, about the puzzles ahead:

"As recent empirical research has amply demonstrated, financial crisis follows credit boom; this is somewhat of a puzzle, but the most challenging puzzle in my opinion is that credit flows (both gross and net) increase in the run up of crisis, only to crash precipitously after the crisis' onset. ... In other words, if herding is the key word, forget about microfoundations of macroeconomics. I must confess that I am not ready to take such a radical stance. My view is that perhaps this very puzzling phenomenon is linked to liquidity and, more to the point, endogenous liquidity, a phenomenon that has been largely ignored in 20th century macroeconomics."

In other words, sudden stops are associated with collapse of liquidity, and those might be associated to herding behavior, which is irrational and is not amenable to formalizing microfoundations along conventional lines. There are so many misconceptions in this quote that one wonders when is he going to get the Sveriges Riksbank Prize (the often referred to as Nobel).

Endogenous liquidity, or endogenous money is no puzzle, and in fact, mainstream models that accept a Taylor rule have basically incorporated it, like Wicksell. Herding is not that complicated to understand, and is NOT the main problem with microfoundations. The problem with microfoundations is not lack of rationality of economic agents, but the fact that even with very rational (even by the limited mainstream standards) you cannot prove that markets lead to full utilization of resources, with flexible prices and full information (yes please go read on the capital debates).

Note that the effects of debt-deflation on demand are not discussed by Calvo. Or income distribution for that matter. Let alone the recognition that the idea of a natural rate is very difficult to defend, and I don't even mean logically, just empirically after this crisis. The essential information out of this piece is about the degree of confusion of the mainstream. It is increasingly clear that that we are living in a period of decadence of economics as a science, in which the profession is dominated by Vulgar economics.

Teaching macro after the crisis

Wendy Carlin and David Soskice have an interesting post at Voxeu.org on "How should macroeconomics be taught to undergraduates in the post-crisis era." They explicitly follow, as in their manual, a New Keynesian framework. Which is an ISMP model with price rigidities, which are incorporated in a slow adjusting Phillips curve with imperfections (they refer to it as the ISPCMR model). Also, they add the financial system. I should make clear that in many respects it is an improvement on some of the newer manuals around, which since the 1990s have given less attention to the possibilities of crises, and have emphasized long term growth (presenting the Solow model in the initial chapters).

From a methodological point of view I would also agree with the notion that "undergraduates need a unified integrated model through which they can understand the major business cycle events of the past century and see how economic theories and policy regimes have evolved in response to these events." Mind you I would go further, it's not just the undergrads, but the profession that needs a unified integrated model to understand the functioning of the macroeconomy. The ad hoc nature of much of the macroeconomic field has been caused by the wrongheaded search for neoclassical microfoundations for macroeconomics. And the authors should be more forceful in denying the relevance of microfoundations.

Having said that, there are significant problems with their way of teaching macro, from my point of view. Carlin and Soskice suggest that "the most glaring absence in macroeconomic models and courses, [is] that of the financial sector." Mind you I would disagree, even if the financial sector is often an afterthought in most macro discussions for undergrads. The most glaring problem is the presence of a natural rate, which implies that in the absence of imperfections markets would produce full utilization of resources. Note that, in their model, Carlin and Soskice have a level of the rate of interest that equilibrates the goods market (IS) with stable inflation, and note that this would be for Woodford "the Wicksellian or natural rate of interest."

They think that they avoid the problem because in their model the equilibrium rate "changes whenever the IS curve shifts," which is of course a confusion, since that would be true of the Wicksellian rate of interest too. With changes in investment and savings (IS) behavior, that is, productivity and thrift the neoclassical natural rate must shift. The role of the central bank is to adjust the rate of interest to its natural level. Note that Carlin and Soskice confuse the fact that monetary and real shocks affect the economy with the notion that the economy described by their model is "an economy which is not self-stabilising."

In their view, the monetary authority can move the economy to the equilibrium rate, but the equilibrium rate is not controlled by the authorities. I would suggest that the central bank actually has control of the key variable, which is not natural at all, and as Keynes suggested is conventional, the normal rate of interest. And that could be set at a level which will not lead to full employment, particularly for distributive reasons. In my view the essential feature of a more relevant macro model would be the elimination of the natural rate, the idea that the system has a tendency to bounce back to the trend, and the notion still in the Carlin and Soskice model that the output gap, the deviation from optimal output, has significant impact on inflation.

Further, in order to introduce the effects of the financial system, while it is welcome that the behavior of banking is introduced, the most important development of the last three decades, the increased financialization, and the shadow banking system, would be better incorporated by introducing the effects of debt and income distribution on the consumption function, which remains based on the permanent income in their model. And by the way, the model says nothing about how income distribution affects spending.Yet, the main reason behind the crisis has been the fact that workers had to get indebted, since income has stagnated. So income distribution has to be brought back to macroeconomics. Not enough Kalecki, with their New (but still neoclassical) version of Keynesianism, that is the problem with Carlin and Soskice.

Microfoundations and the capital debates

Steve has commented on the ongoing debates about microfoundations of macroeconomics, mainly between Paul Krugman and Simon Wren-Lewis (for my comments and Simon's reply on his blog go here, and scroll down to the last comments). I just want to further clarify what I think is, from the point of view of the history of ideas, a significant confusion in the debates about microfoundations, and one (oh yes, here he comes again) that is ultimately related to the capital debates (the Rosetta Stone of the history of economics ideas; if you prefer Sraffa's PCMC, as I tell my students, is the Rosetta Stone. To get an idea of what is the meaning of the capital debates go here).

Microfoundations are first and foremost about the determination of relative prices, the core of what we now call microeconomics, and used to be called before the theory of value. Individual behavior, rational or otherwise, is relevant to the extent that one thinks that behavior of individual agents is central for price determination, and that was at the core of the Marginalist Revolution.

The point is that if individual workers (using the figure of a representative rational utility maximizing worker), for example, in the labor market, confronts rational individual profit maximizing firms (again a representative firm), the free play of the market would produce an optimal outcome. Krugman is very clear why he thinks microfoundations are important. He says:

“if the assumption of perfect rationality breaks down even in the most standard of micro settings — if consumers behave in a way inconsistent with full maximization even when doing something as mundane as choosing which type of gas to put in their tank — how absurd is it to insist that, say, Keynesian stories about the economy can’t be right because we can’t fully derive them from intertemporal maximization?”

In other words, if workers say are not concerned with maximizing utility in terms of higher real wages, but in terms of relative wages, or if firms have limited knowledge about the workers willingness to work, and have an incentive to pay wages above the reservation wage (the one that compensates workers for the trouble with parting with leisure time), then the imperfection implies that the labor market will not clear and you might have unemployment. This is basically the efficiency wage story that New Keynesians use to justify unemployment (note that unemployment does result from real wages above the equilibrium level, and not from lack of demand as in Keynes).*

The capital debates show that even if you have workers trying to maximize utility in the normal fashion, and firms too have full information, that is, in the absence of any imperfection, there is no guarantee that lower real wages would imply more intensive use of the labor ‘factor.’ It is actually quite simple, if commodities are produced with commodities, then a reduction in wages also reduces the price of all goods, since they are produced with labor too, and there is a possibility that the fall in the price of commodities that do not use too much labor falls more than proportionally, so the increase in their demand does not lead to an increase in the hiring of new workers. Also, as wages are central for the consumer’s demand, the income effect of any reduction in wages would trump any (if it is positive) substitution effect. In other words, why would a firm hire more workers (even cheap ones) if nobody buys their products?

Further, PCMC does provide a sound way of determining relative prices. Long term normal prices are determined by the technical conditions of production, given one distributive variable (either real wages or interest, or if one prefers, for a given wage-profit frontier). It does take long term patterns of demand as given obviously, since producers would not supply, in the long term, goods and services for which there is no demand. The analysis of the determinants of effectual demand, the long term patterns of demand, are at a lower level of abstraction, and include all the institutional factors associated to fashion, conspicuous display of power, the effects of marketing, etc., that Veblen, Galbraith (father) and other institutionalist authors suggested were relevant.

Also, workers are rationally trying to obtain a fair wage, and to consume according to their tastes and the other social and institutional factors that determine their behavior. But those are taken as given for the determination of long run prices. And firms do maximize profits, and this implies that they add a mark up on their full costs. These models were developed by the authors of the Full Cost Pricing School, and the literature on barriers to entry, e.g. Sylos-Labini, Steindl and others, and the empirical evidence tends to be favorable.

In that sense, heterodox (classical-Keynesian, by which I mean Sraffa’s prices cum Keynes/Kalecki’s effective demand) does have a coherent determination of long run prices, based on rational behavior, as the foundation of the macroeconomic theory. Markets do not produce optimal outcomes and unemployment of productive resources is the normal, long run, position of the economy. In fact, the capital debates not only say that classical political economy (the surplus approach) provides sound microfoundations, but also that it is NOT possible to do so within the neoclassical/marginalist paradigm.***

* Interestingly enough Krugman’s argument for the current recession is not a rigidity in the labor market, but one in the money market, that is, a rate of interest that does not allow for investment at the level of full employment savings, the so-called Liquidity Trap.

** And yes there is empirical evidence in favor of this view, since there is no support for the effect of lower real wages and higher employment. Real wages tend to be pro-cyclical, go down in a recession, and up in the boom.

*** Arrow-Debreu also does not provide a way out of this conundrum.

PS: For the implications of Sraffa's contribution for Keynesian economics see this paper, and this post.

A Critique of the Lucas Critique

The blogosphere, it seems recently, has been particularly rich in blogoyakking (sp?) concerning microfoundations. Wren-Lewis, Noah Smith, Krugman, Rowe, Plosser, and others just in the week prior to this post.

And this has caused a persistent itch of mine to clamor for scratching. Here goes.

The Lucas critique is fairly widely acknowledged to have at least exacerbated the trend toward insisting on microfoundations in macro theory, and thus the rise of New Keynesian Dynamic Stochastic General Equilibrium models. You know, representative agents showing rational expectations over generations, and all such things, reacting to policy changes. Which individual behaviors we can, more or less simply, just add up in order to understand the effects on the macro economy.

For those needing a brief review on "the" critique, Wikipedia is actually not bad, which I summarize. Lucas said:

"Given that the structure of an econometric model consists of optimal decision rules of economic agents, and that optimal decision rules vary systematically with changes in the structure of series relevant to the decision maker, it follows that any change in policy will systematically alter the structure of econometric models."

This is from his 1976 paper.

And the Wiki article summarizes the implications:

"The Lucas critique suggests that if we want to predict the effect of a policy experiment, we should model the "deep parameters" (relating to preferences, technology and resource constraints) that govern individual behavior. We can then predict what individuals will do, taking into account the change in policy, and then aggregate the individual decisions to calculate the macroeconomic effects of the policy change."

Thus, Bortis-style classical-Keynesianism was pretty much denuded: at best macro policy is effectively toothless, since that pesky agent will simply react to neutralize the policy actions;  and/or react so that the empirical regularities we were observing and making policy on will change. So we need to focus on micro and get that "right," the best we can do. The domination of Methodological Individualism on economic practice was on the rise.

I think Lucas got part of the diagnosis correct: individuals do react to macro policy changes but only indirectly. And he got most of it wrong. For the most part individual behaviors do not  directly change the  structure of the time series, but it is the change in the structure of the time series that changes individual behavior. Aggregate demand falls due to some shock - asset deflation, price shocks, war, pestilence, loss of income due to technology or offshoring. Producers then decrease output, and fire their workers.

This shock mechanism does induce individually optimizing behavior on the part of the business owner, given that what he optimizes is his profit function into which his production output enters.

For the newly unemployed person, since s/he no longer has a source of income, one can stretch and say that reducing consumption is individually optimizing at least of negative deviations from the budget. Of course this mechanism has it's own brutal zero lower bound - subsistence.  And does nothing to maximize utility.

Notice, no macro policy change is required here to start a recession or the recent depression; all we need is a sufficient shock to the system to start the negative feedback cycles rolling along.

We classical-Keynesian macroeconomists characterize these mechanisms as showing the fallacy of composition; the canonical principles of economics example is the paradox of thrift. You cannot use added-up individually optimizing behaviors to determine what is going to happen to the macro economy.

The reason is clear: emergent properties at the macro level have a life of their own. And its is these emergent properties like recessions and unemployment that directly affect the behavior of the economic person. I take here the strong version of emergent: a property or behavior at the aggregate level which cannot be observed or predicted at the individual level.

We do have methods that attempt to model this: the Keynesian aggregate expenditure model, but that is static. Dynamic macro econometric models, but those are difficult, and maybe it was because of these difficulties that the Lucas critique was so successful in attacking them.

I propose two things to restore the dominating importance of emergent macro properties on economic behavior. One is a recommitment to econometric modelling. Ever increasing data and increasingly better tools will continually improve modelling and forecasting results.

The other is a methodology that is vastly underused in economics, but widely used in various other sciences: network system analysis based on the mathematical theory of graphs. These methods lets us directly measure and model emergent dynamic behaviors from groups, like the individuals in an economy. No added up methodological individualism required; no agent-based model needed. Observe, model, and predict directly at the macro level.

While I believe empirical models, properly done, are fundamental to understanding and policy, network models provide us with a dynamic theory, emergent macro behaviors, that  support our correct Keynesian beliefs that it is the macro foundations of micro behavior that matter, not the other Lucasian way around.