Posts Tagged 'Samuelson'

The Neoclassical Synthesis and the Mind-Body Problem

The neoclassical synthesis that emerged in the early postwar period aimed at reconciling the macroeconomic (IS-LM) analysis derived from Keynes via Hicks and others with the neoclassical microeconomic analysis of general equilibrium derived from Walras. The macroeconomic analysis was focused on an equilibrium of income and expenditure flows while the Walrasian analysis was focused on the equilibrium between supply and demand in individual markets. The two types of analysis seemed to be incommensurate inasmuch as the conditions for equilibrium in the two analysis did not seem to match up against each other. How does an analysis focused on the equality of aggregate flows of income and expenditure get translated into an analysis focused on the equality of supply and demand in individual markets? The two languages seem to be different, so it is not obvious how a statement formulated in one language gets translated into the other. And even if a translation is possible, does the translation hold under all, or only under some, conditions? And if so, what are those conditions?

The original neoclassical synthesis did not aim to provide a definitive answer to those questions, but it was understood to assert that if the equality of income and expenditure was assured at a level consistent with full employment, one could safely assume that market forces would take care of the allocation of resources, so that markets would be cleared and the conditions of microeconomic general equilibrium satisfied, at least as a first approximation. This version of the neoclassical synthesis was obviously ad hoc and an unsatisfactory resolution of the incommensurability of the two levels of analysis. Don Patinkin sought to provide a rigorous reconciliation of the two levels of analysis in his treatise Money, Interest and Prices. But for all its virtues – and they are numerous – Patinkin’s treatise failed to bridge the gap between the two levels of analysis.

As I mentioned recently in a post on Romer and Lucas, Kenneth Arrow in a 1967 review of Samuelson’s Collected Works commented disparagingly on the neoclassical synthesis of which Samuelson was a leading proponent. The widely shared dissatisfaction expressed by Arrow motivated much of the work that soon followed on the microfoundations of macroeconomics exemplified in the famous 1970 Phelps volume. But the motivation for the search for microfoundations was then (before the rational expectations revolution) to specify the crucial deviations from the assumptions underlying the standard Walrasian general-equilibrium model that would generate actual or seeming price rigidities, which a straightforward – some might say superficial — understanding of neoclassical microeconomic theory suggested were necessary to explain why, after a macro-disturbance, equilibrium was not rapidly restored by price adjustments. Two sorts of explanations emerged from the early microfoundations literature: a) search and matching theories assuming that workers and employers must expend time and resources to find appropriate matches; b) institutional theories of efficiency wages or implicit contracts that explain why employers and workers prefer layoffs to wage cuts in response to negative demand shocks.

Forty years on, the search and matching theories do not seem capable of accounting for the magnitude of observed fluctuations in employment or the cyclical variation in layoffs, and the institutional theories are still difficult to reconcile with the standard neoclassical assumptions, remaining an ad hoc appendage to New Keynesian models that otherwise adhere to the neoclassical paradigm. Thus, although the original neoclassical synthesis in which the Keynesian income-expenditure model was seen as a pre-condition for the validity of the neoclassical model was rejected within a decade of Arrow’s dismissive comment about the neoclassical synthesis, Tom Sargent has observed in a recent review of Robert Lucas’s Collected Papers on Monetary Theory that Lucas has implicitly adopted a new version of the neoclassical synthesis dominated by an intertemporal neoclassical general-equilibrium model, but with the proviso that substantial shocks to aggregate demand and the price level are prevented by monetary policy, thereby making the neoclassical model a reasonable approximation to reality.

Ok, so you are probably asking what does all this have to do with the mind-body problem? A lot, I think in that both the neoclassical synthesis and the mind-body problem involve a disconnect between two kinds – two levels – of explanation. The neoclassical synthesis asserts some sort of connection – but a problematic one — between the explanatory apparatus – macroeconomics — used to understand the cyclical fluctuations of what we are used to think of as the aggregate economy and the explanatory apparatus – microeconomics — used to understand the constituent elements of the aggregate economy — households and firms — and how those elements are related to, and interact with, each other.

The mind-body problem concerns the relationship between the mental – our direct experience of a conscious inner life of thoughts, emotions, memories, decisions, hopes and regrets — and the physical – matter, atoms, neurons. A basic postulate of science is that all phenomena have material causes. So the existence of conscious states that seem to us, by way of our direct experience, to be independent of material causes is also highly problematic. There are a few strategies for handling the problem. One is to assert that the mind truly is independent of the body, which is to say that consciousness is not the result of physical causes. A second is to say that mind is not independent of the body; we just don’t understand the nature of the relationship. There are two possible versions of this strategy: a) that although the nature of the relationship is unknown to us now, advances in neuroscience could reveal to us the way in which consciousness is caused by the operation of the brain; b) although our minds are somehow related to the operation of our brains, the nature of this relationship is beyond the capacity of our minds or brains to comprehend owing to considerations analogous to Godel’s incompleteness theorem (a view espoused by the philosopher Colin McGinn among others); in other words, the mind-body problem is inherently beyond human understanding. And the third strategy is to deny the existence of consciousness, because a conscious state is identical with the physical state of a brain, so that consciousness is just an epiphenomenon of a brain state; we in our naivete may think that our conscious states have a separate existence, but those states are strictly identical with corresponding brain states, so that whatever conscious state that we think we are experiencing has been entirely produced by the physical forces that determine the behavior of our brains and the configuration of its physical constituents.

The first, and probably the last, thing that one needs to understand about the third strategy is that, as explained by Colin McGinn (see e.g., here), its validity has not been demonstrated by neuroscience or by any other branch of science; it is, no less than any of the other strategies, strictly a metaphysical position. The mind-body problem is a problem precisely because science has not even come close to demonstrating how mental states are caused by, let alone that they are identical to, brain states, despite some spurious misinterpretations of research that purport to show such an identity.

Analogous to the scientific principle that all phenomena have material or physical causes, there is in economics and social science a principle called methodological individualism, which roughly states that explanations of social outcomes should be derived from theories about the conduct of individuals, not from theories about abstract social entities that exist independently of their constituent elements. The underlying motivation for methodological individualism (as opposed to political individualism with which it is related but from which it is distinct) was to counter certain ideas popular in the nineteenth and twentieth centuries asserting the existence of metaphysical social entities like “history” that are somehow distinct from yet impinge upon individual human beings, and that there are laws of history or social development from which future states of the world can be predicted, as Hegel, Marx and others tried to do. This notion gave rise to a two famous books by Popper: The Open Society and its Enemies and The Poverty of Historicism. Methodological individualism as articulated by Popper was thus primarily an attack on the attribution of special powers to determine the course of future events to abstract metaphysical or mystical entities like history or society that are supposedly things or beings in themselves distinct from the individual human beings of which they are constituted. Methodological individualism does not deny the existence of collective entities like society; it simply denies that such collective entities exist as objective facts that can be observed as such. Our apprehension of these entities must be built up from more basic elements — individuals and their plans, beliefs and expectations — that we can apprehend directly.

However, methodological individualism is not the same as reductionism; methodological individualism teaches us to look for explanations of higher-level phenomena, e.g., a pattern of social relationships like the business cycle, in terms of the basic constituents forming the pattern: households, business firms, banks, central banks and governments. It does not assert identity between the pattern of relationships and the constituent elements; it says that the pattern can be understood in terms of interactions between the elements. Thus, a methodologically individualistic explanation of the business cycle in terms of the interactions between agents – households, businesses, etc. — would be analogous to an explanation of consciousness in terms of the brain if an explanation of consciousness existed. A methodologically individualistic explanation of the business cycle would not be analogous to an assertion that consciousness exists only as an epiphenomenon of brain states. The assertion that consciousness is nothing but the epiphenomenon of a corresponding brain state is reductionist; it asserts an identity between consciousness and brain states without explaining how consciousness is caused by brain states.

In business-cycle theory, the analogue of such a reductionist assertion of identity between higher-level and lower level phenomena is the assertion that the business cycle is not the product of the interaction of individual agents, but is simply the optimal plan of a representative agent. On this account, the business cycle becomes an epiphenomenon; apparent fluctuations being nothing more than the optimal choices of the representative agent. Of course, everyone knows that the representative agent is merely a convenient modeling device in terms of which a business-cycle theorist tries to account for the observed fluctuations. But that is precisely the point. The whole exercise is a sham; the representative agent is an as-if device that does not ground business-cycle fluctuations in the conduct of individual agents and their interactions, but simply asserts an identity between those interactions and the supposed decisions of the fictitious representative agent. The optimality conditions in terms of which the model is solved completely disregard the interactions between individuals that might cause an unintended pattern of relationships between those individuals. The distinctive feature of methodological individualism is precisely the idea that the interactions between individuals can lead to unintended consequences; it is by way of those unintended consequences that a higher-level pattern might emerge from interactions among individuals. And those individual interactions are exactly what is suppressed by representative-agent models.

So the notion that any analysis premised on a representative agent provides microfoundations for macroeconomic theory seems to be a travesty built on a total misunderstanding of the principle of methodological individualism that it purports to affirm.

In Praise of Israel Kirzner

Over the holiday weekend, I stumbled across, to my pleasant surprise, the lecture given just a week ago by Israel Kirzner on being awarded the 2015 Hayek medal by the Hayek Gesellschaft in Berlin. The medal, it goes without saying, was richly deserved, because Kirzner’s long career spanning over half a century has produced hundreds of articles and many books elucidating many important concepts in various areas of economics, but especially on the role of competition and entrepreneurship (the title of his best known book) in theory and in practice. A student of Ludwig von Mises, when Mises was at NYU in the 1950s, Kirzner was able to recast and rework Mises’s ideas in a way that made them more accessible and more relevant to younger generations of students than were the didactic and dogmatic pronouncements so characteristic of Mises’s own writings. Not that there wasn’t and still isn’t a substantial market niche in which such didacticism and dogmatism is highly prized, but there are also many for whom those features of the Misesian style don’t go down quite so easily.

But it would be very unfair, and totally wrong, to think of Kirzner as a mere popularizer of Misesian doctrines. Although in his modesty and self-effacement, Kirzner made few, if any, claims of originality for himself, his application of ideas that he learned from, or, having developed them himself, read into, Mises, Kirzner’s contributions in their own way were not at all lacking originality and creativity. In a certain sense, his contribution was, in its own way, entrepreneurial, i.e., taking a concept or an idea or an analytical tool applied in one context and deploying that concept, idea, or tool in another context. It’s worth mentioning that a reverential attitude towards one’s teachers and intellectual forbears is not only very much characteristic of the Talmudic tradition of which Kirzner is also an accomplished master, but it’s also characteristic, or at least used to be, of other scholarly traditions, notably Cambridge, England, where such illustrious students of Alfred Marshall as Frederick Lavington and A. C. Pigou viewed themselves as merely elaborating on doctrines that had already been expounded by Marshall himself, Pigou having famously said of his own voluminous work, “it’s all in Marshall.”

But rather than just extol Kirzner’s admirable personal qualities, I want to discuss what Kirzner said in his Hayek lecture. His main point was to explain how, in his view, the Austrian tradition, just as it seemed to be petering out in the late 1930s and 1940s, evolved from just another variant school of thought within the broader neoclassical tradition that emerged late in the 19th century from the marginal revolution started almost simultaneously around 1870 by William Stanley Jevons in England, Carl Menger in Austria, and Leon Walras in France/Switzerland, into a completely distinct school of thought very much at odds with the neoclassical mainstream. In Kirzner’s view, the divergence between Mises and Hayek on the one hand and the neoclassical mainstream on the other was that Mises and Hayek went further in developing the subjectivist paradigm underlying the marginal-utility theory of value introduced by Jevons, Menger, and Walras in opposition to the physicalist, real-cost, theory of value inherited from Smith, Ricardo, Mill, and other economists of the classical school.

The marginal revolution shifted the focus of economics from the objective physical and technological forces that supposedly determine cost, which, in turn, supposedly determines value, to subjective, not objective, mental states or opinions that characterize preferences, which, in turn, determine value. And, as soon became evident, the new subjective marginalist theory of value implied that cost, at bottom, is nothing other than a foregone value (opportunity cost), so that the classical doctrine that cost determines value has it exactly backwards: it is really value that determines cost (though it is usually a mistake to suppose that in complex systems causation runs in only one direction).

However, as the neoclassical research program evolved, the subjective character of the underlying theory was increasingly de-emphasized, a de-emphasis that was probably driven by two factors: 1) the profoundly paradoxical nature of the idea that value determines cost, not the reverse, and b) the mathematicization of economics and the increasing adoption, in the Walrasian style, of functional representations of utility and production, leading to the construction of models of economic equilibrium that, under appropriate continuity and convexity assumptions, could be shown to have a theoretically determinate and unique solution. The false impression was created that economics was an objective science like physics, and that economics should aim to create objective and deterministic scientific representations (models) of complex economic systems that could then yield quantitatively precise predictions, in the same way that physics produced models of planetary motion yielding quantitatively precise predictions.

What Hayek and Mises objected to was the idea, derived from the functional approach to economic theory, that economics is just a technique of optimization subject to constraints, that all economic problems can be reduced to optimization problems. And it is a historical curiosum that one of the chief contributors to this view of economics was none other than Lionel Robbins in his seminal methodological work An Essay on the Nature and Significance of Economic Science, written precisely during that stage of his career when he came under the profound influence of Mises and Hayek, but before Mises and Hayek adopted the more radically subjective approach that characterizes their views in the late 1930s and 1940s. The critical works are Hayek’s essays reproduced as The Counterrevolution of Science and his essays “Economics and Knowledge,” “The Facts of the Social Sciences,” “The Use of Knowledge in Society,” and “The Meaning of Competition,” all contained in the remarkable volume Individualism and Economic Order.

What neoclassical economists who developed this deterministic version of economic theory, a version wonderfully expounded in Samuelson Foundations of Economic Analysis and ultimately embodied in the Arrow-Debreu general-equilibrium model, failed to see is that the model could not incorporate in an intellectually satisfying or empirically fruitful way the process of economic growth and development. The fundamental characteristic of the Arrow-Debreu model is its perfection. The solution of the model is Pareto-optimal, and cannot be improved upon; the entire unfolding of the model from beginning to end proceeds entirely according to a plan (actually a set of perfectly consistent and harmonious individual plans) with no surprises and no disappointments relative to what was already foreseen and planned — in detail — at the outset. Nothing is learned in the unfolding and execution of those detailed, perfectly harmonious plans that was not already known at the beginning, whatever happens having already been foreseen. If something truly new would have been learned in the course of the unfolding and execution of those plans, the new knowledge would necessarily have been surprising, and a surprise would necessarily have generated some disappointment and caused some revision of a previously formulated plan of action. But that is precisely what the Arrow-Debreu model, in its perfection, disallows. And that is what, from the perspective of Mises, Hayek, and Kirzner, is exactly wrong with the entire development of neoclassical theory for the past 80 years or more.

The specific point of the neoclassical paradigm on which Kirzner has focused his criticism is the inability of the neoclassical paradigm to find a place for the entrepreneur and entrepreneurial activity in its theoretical apparatus. Profit is what is earned by the entrepreneur, but in full general equilibrium, all income is earned by factors of production, so profits have been exhausted and the entrepreneur euthanized.

Joseph Schumpeter, who was torn between his admiration for the Walrasian general equilibrium system and his Austrian education in economics, tried to reintroduce the entrepreneur as the disruptive force behind the process of creative destruction, the role of the entrepreneur being to disrupt the harmonious equilibrium of the Walrasian system by innovating – introducing either new techniques of production or new consumer products. Kirzner, however, though not denying that disruptive Schumpeterian entrepreneurs may come on the scene from time to time, is focused on a less disruptive, but more pervasive and more characteristic type of entrepreneurship, the kind that is on the lookout for – that is alert to – the profit opportunities that are always latent in the existing allocation of resources and the current structure of input and output prices. Prices in some places or at some times may be high relative to other places and other times, so the entrepreneurial maxim is: buy cheap and sell dear.

Not so long ago, someone noticed that used book prices on Amazon are typically lower at the end of the semester or the school year, when students are trying to unload the books that they don’t want to keep, than they are at the beginning of the semester, when students are buying the books that they will have to read in the new semester. By buying the books students are selling at the end of the school year and selling them at the beginning of the school year, the insightful entrepreneur reduces the cost to students of obtaining the books they use during the school year. That bit of insight and alertness is classic Kirznerian entrepreneurship in action; it was rewarded by a profit, but the activity was equilibrating, not disruptive, reducing the spread between prices for the same, or very similar, commodities paid by buyers or received by sellers at different times of the year.

Sometimes entrepreneurship involves recognizing that a resource or a factor of production is undervalued in its current use. Shifting the resource from a relatively low-valued use to a higher-value use generates a profit for the alert entrepreneur. Here, again, the activity is equilibrating not disruptive. And as others start to catch on, the profit earned on the spread between the value of the resource in its old and new uses will be eroded by the competition of copy-cat entrepreneurs and of other entrepreneurs with an even better idea derived from an even more penetrating insight.

Here is another critical point. Rarely does a new idea come into existence and cause just one change. Every change creates a new and different situation, potentially creating further opportunities to be taken advantage of by other alert and insightful individuals. In an open competitive system, there is no reason why the process of discovery and adaptation should ever come to an end state in which new insights can no longer be made and change is no longer possible.

However, it also the case that knowledge or information is often imperfect and faulty, and that incentives are imperfectly aligned with actual benefits, so that changes can be profitable even though they lead to inferior outcomes. Margarine can be substituted for butter, and transfats for saturated fats. Big mistake. But who knew? And processed carbohydrates can replace fats in low-fat diets. Big mistake. But who knew?

I myself had the pleasure of experiencing first-hand, on a very small scale to be sure, but still in a very inspiring way, this sort of unplanned, serendipitous connection between my stumbling across Kirzner’s Hayek lecture and, then, after starting to write this post a couple of days ago, doing a Google search on Kirzner plus something else (can’t remember what) and seeing a link to Deirdre McCloskey’s paper “A Kirznerian Economic History of the Modern World” in which McCloskey, in somewhat over-the-top style, waxed eloquent about the long and circuitous evolution of her views from the strict neoclassicism in which she was indoctrinated at Harvard and later at Chicago to Kirznerian Austrianism. McCloskey observes in her wonderful paean to Kirzner that growth theory (which is now the core of modern macroeconomics) is utterly incapable of accounting for the historically unique period of economic growth over the past 200 years in what we now refer to as the developed world.

I had faced repeatedly 1964 to 2010 the failure of oomph in the routine, Samuelsonian arguments, such as accumulation inspired by the Protestant ethic, or trade as an engine of growth, or Marxian exploitation, or imperialism as the last stage of capitalism, or factor-biased induced technical change, or Unified Growth Theory. My colleagues at the University of Chicago in the 1970s, Al Harberger and Bob Fogel, pioneered the point that Harberger Triangles of efficiency gain are small (Harberger 1964; Fogel 1965). None of the allocative, capital-accumulation explanations of economic growth since Adam Smith have worked scientifically, which I show in depressing detail in Bourgeois Dignity. None of them have the quantitative force and the distinctiveness to the modern world and the West to explain the Great Fact. No oomph.

What works? Creativity. Innovation. Discovery. The Austrian core. And where did discovery come from? It came from the releasing of the West from ancient constraints on the dignity and liberty of the bourgeoisie, producing an intellectual and engineering explosion of ideas. As the banker and science writer Matt Ridley has recently described it (2010; compare Storr 2008), ideas started breeding, and having baby ideas, who bred further. The liberation of the Jews in the West is a good emblem for the wider story. A people of the book began to be allowed into commercial centers in Holland and then England, and allowed outside the shtetl and the ghetto, and into the universities of Berlin and Manchester. They commenced innovating on a massive, breeding-reactor scale, in good ways (Rothschild, Einstein) and in bad (Marx, Freud).

Ridley explains how the evolutionary biologist Leigh Van Valen proposed in 1973 a Red Queen Hypothesis that would explain why commercial and mechanical ideas, when first allowed to evolve, had to run faster and faster to stay in the same place. Economists would call it the dissipation of initial rents, in the second and third acts of the economic drama. Once breeding ideas were set free in the seventeenth century they created more and more opportunities for Kirznerian alertness. The opportunities were alertly taken up, and persuasively argued for, and at length routinized. The idea of the steam engine had babies with the idea of rails and the idea of wrought iron, and the result was the railroads. The new generation of ideas-in view of the continuing breeding of ideas going on in the background-created by their very routinization still more Kirznerian opportunities. Railroads once they were routine led to Sears, Roebuck and Montgomery Ward. And the routine then created prosperous people, such as my grandfather the freight conductor on the Milwaukee Road or my great-grandfather the postal clerk on the Chicago & Western Indiana or my other great-grandfather who invented the ring on telephones (which extended the telegraph, which itself had made tight scheduling of trains possible). Some became prosperous enough to take up the new ideas, and all became prosperous enough under the Great Fact to buy them. If there was no dissipation of the rents to alertness, and no ultimate gain of income to hoi polloi, no third act, no Red Queen effect, then innovation would not have a justification on egalitarian grounds-as in the historical event it surely did have. The Bosses would engorge all the income, as Ricardo in the early days of the Great Fact had feared. But in the event the discovery of which Kirzner and the Austrian tradition speaks enriched in the third act mainly the poor-your ancestors, and Israel’s, and mine.

It is the growth and diffusion of knowledge (both practical and theoretical, but especially the former), not the accumulation of capital, that accounts for the spectacular economic growth of the past two centuries. So, all praise to the Austrian economist par excellence, Israel Kirzner. But just to avoid any misunderstanding, I will state for the record, that my admiration for Kirzner does not mean that I have gone wobbly on the subject of Austrian Business Cycle Theory, a subject on which Kirzner has been, so far as I know, largely silent — yet further evidence – as if any were needed — of Kirzner’s impeccable judgment.

Franklin Fisher on the Stability(?) of General Equilibrium

The eminent Franklin Fisher, winner of the J. B. Clark Medal in 1973, a famed econometrician and antitrust economist, who was the expert economics witness for IBM in its long battle with the U. S. Department of Justice, and was later the expert witness for the Justice Department in the antitrust case against Microsoft, currently emeritus professor professor of microeconomics at MIT, visited the FTC today to give a talk about proposals the efficient sharing of water between Israel, Palestine, and Jordan. The talk was interesting and informative, but I must admit that I was more interested in Fisher’s views on the stability of general equilibrium, the subject of a monograph he wrote for the econometric society Disequilibrium Foundations of Equilibrium Economics, a book which I have not yet read, but hope to read before very long.

However, I did find a short paper by Fisher, “The Stability of General Equilibrium – What Do We Know and Why Is It Important?” (available here) which was included in a volume General Equilibrium Analysis: A Century after Walras edited by Pacal Bridel.

Fisher’s contribution was to show that the early stability analyses of general equilibrium, despite the efforts of some of the most best economists of the mid-twentieth century, e.g, Hicks, Samuelson, Arrow and Hurwicz (all Nobel Prize winners) failed to provide a useful analysis of the question whether the general equilibrium described by Walras, whose existence was first demonstrated under very restrictive assumptions by Abraham Wald, and later under more general conditions by Arrow and Debreu, is stable or not.

Although we routinely apply comparative-statics exercises to derive what Samuelson mislabeled “meaningful theorems,” meaning refutable propositions about the directional effects of a parameter change on some observable economic variable(s), such as the effect of an excise tax on the price and quantity sold of the taxed commodity, those comparative-statics exercises are predicated on the assumption that the exercise starts from an initial position of equilibrium and that the parameter change leads, in a short period of time, to a new equilibrium. But there is no theory describing the laws of motion leading from one equilibrium to another, so the whole exercise is built on the mere assumption that a general equilibrium is sufficiently stable so that the old and the new equilibria can be usefully compared. In other words, microeconomics is predicated on macroeconomic foundations, i.e., the stability of a general equilibrium. The methodological demand for microfoundations for macroeconomics is thus a massive and transparent exercise in question begging.

In his paper on the stability of general equilibrium, Fisher observes that there are four important issues to be explored by general-equilibrium theory: existence, uniqueness, optimality, and stability. Of these he considers optimality to be the most important, as it provides a justification for a capitalistic market economy. Fisher continues:

So elegant and powerful are these results, that most economists base their conclusions upon them and work in an equilibrium framework – as they do in partial equilibrium analysis. But the justification for so doing depends on the answer to the fourth question listed above, that of stability, and a favorable answer to that is by no means assured.

It is important to understand this point which is generally ignored by economists. No matter how desirable points of competitive general equilibrium may be, that is of no consequence if they cannot be reached fairly quickly or maintained thereafter, or, as might happen when a country decides to adopt free markets, there are bad consequences on the way to equilibrium.

Milton Friedman remarked to me long ago that the study of the stability of general equilibrium is unimportant, first, because it is obvious that the economy is stable, and, second, because if it isn’t stable we are wasting our time. He should have known better. In the first place, it is not at all obvious that the actual economy is stable. Apart from the lessons of the past few years, there is the fact that prices do change all the time. Beyond this, however, is a subtler and possibly more important point. Whether or not the actual economy is stable, we largely lack a convincing theory of why that should be so. Lacking such a theory, we do not have an adequate theory of value, and there is an important lacuna in the center of microeconomic theory.

Yet economists generally behave as though this problem did not exist. Perhaps the most extreme example of this is the view of the theory of Rational Expectations that any disequilibrium disappears so fast that it can be ignored. (If the 50-dollar bill were really on the sidewalk, it would be gone already.) But this simply assumes the problem away. The pursuit of profits is a major dynamic force in the competitive economy. To only look at situations where the Invisible Hand has finished its work cannot lead to a real understanding of how that work is accomplished. (p. 35)

I would also note that Fisher confirms a proposition that I have advanced a couple of times previously, namely that Walras’s Law is not generally valid except in a full general equilibrium with either a complete set of markets or correct price expectations. Outside of general equilibrium, Walras’s Law is valid only if trading is not permitted at disequilibrium prices, i.e., Walrasian tatonnement. Here’s how Fisher puts it.

In this context, it is appropriate to remark that Walras’s Law no longer holds in its original form. Instead of the sum of the money value of all excess demands over all agents being zero, it now turned out that, at any moment of time, the same sum (including the demands for shares of firms and for money) equals the difference between the total amount of dividends that households expect to receive at that time and the amount that firms expect to pay. This difference disappears in equilibrium where expectations are correct, and the classic version of Walras’s Law then holds.


About Me

David Glasner
Washington, DC

I am an economist in the Washington DC area. My research and writing has been mostly on monetary economics and policy and the history of economics. In my book Free Banking and Monetary Reform, I argued for a non-Monetarist non-Keynesian approach to monetary policy, based on a theory of a competitive supply of money. Over the years, I have become increasingly impressed by the similarities between my approach and that of R. G. Hawtrey and hope to bring Hawtrey's unduly neglected contributions to the attention of a wider audience.

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