Archive for the 'Alfred Marshall' Category

An Austrian Tragedy

It was hardly predictable that the New York Review of Books would take notice of Marginal Revolutionaries by Janek Wasserman, marking the susquicentenial of the publication of Carl Menger’s Grundsätze (Principles of Economics) which, along with Jevons’s Principles of Political Economy and Walras’s Elements of Pure Economics ushered in the marginal revolution upon which all of modern economics, for better or for worse, is based. The differences among the three founding fathers of modern economic theory were not insubstantial, and the Jevonian version was largely superseded by the work of his younger contemporary Alfred Marshall, so that modern neoclassical economics is built on the work of only one of the original founders, Leon Walras, Jevons’s work having left little impression on the future course of economics.

Menger’s work, however, though largely, but not totally, eclipsed by that of Marshall and Walras, did leave a more enduring imprint and a more complicated legacy than Jevons’s — not only for economics, but for political theory and philosophy, more generally. Judging from Edward Chancellor’s largely favorable review of Wasserman’s volume, one might even hope that a start might be made in reassessing that legacy, a process that could provide an opportunity for mutually beneficial interaction between long-estranged schools of thought — one dominant and one marginal — that are struggling to overcome various conceptual, analytical and philosophical problems for which no obvious solutions seem available.

In view of the failure of modern economists to anticipate the Great Recession of 2008, the worst financial shock since the 1930s, it was perhaps inevitable that the Austrian School, a once favored branch of economics that had made a specialty of booms and busts, would enjoy a revival of public interest.

The theme of Austrians as outsiders runs through Janek Wasserman’s The Marginal Revolutionaries: How Austrian Economists Fought the War of Ideas, a general history of the Austrian School from its beginnings to the present day. The title refers both to the later marginalization of the Austrian economists and to the original insight of its founding father, Carl Menger, who introduced the notion of marginal utility—namely, that economic value does not derive from the cost of inputs such as raw material or labor, as David Ricardo and later Karl Marx suggested, but from the utility an individual derives from consuming an additional amount of any good or service. Water, for instance, may be indispensable to humans, but when it is abundant, the marginal value of an extra glass of the stuff is close to zero. Diamonds are less useful than water, but a great deal rarer, and hence command a high market price. If diamonds were as common as dewdrops, however, they would be worthless.

Menger was not the first economist to ponder . . . the “paradox of value” (why useless things are worth more than essentials)—the Italian Ferdinando Galiani had gotten there more than a century earlier. His central idea of marginal utility was simultaneously developed in England by W. S. Jevons and on the Continent by Léon Walras. Menger’s originality lay in applying his theory to the entire production process, showing how the value of capital goods like factory equipment derived from the marginal value of the goods they produced. As a result, Austrian economics developed a keen interest in the allocation of capital. Furthermore, Menger and his disciples emphasized that value was inherently subjective, since it depends on what consumers are willing to pay for something; this imbued the Austrian school from the outset with a fiercely individualistic and anti-statist aspect.

Menger’s unique contribution is indeed worthy of special emphasis. He was more explicit than Jevons or Walras, and certainly more than Marshall, in explaining that the value of factors of production is derived entirely from the value of the incremental output that could be attributed (or imputed) to their services. This insight implies that cost is not an independent determinant of value, as Marshall, despite accepting the principle of marginal utility, continued to insist – famously referring to demand and supply as the two blades of the analytical scissors that determine value. The cost of production therefore turns out to be nothing but the value the output foregone when factors are used to produce one output instead of the next most highly valued alternative. Cost therefore does not determine, but is determined by, equilibrium price, which means that, in practice, costs are always subjective and conjectural. (I have made this point in an earlier post in a different context.) I will have more to say below about the importance of Menger’s specific contribution and its lasting imprint on the Austrian school.

Menger’s Principles of Economics, published in 1871, established the study of economics in Vienna—before then, no economic journals were published in Austria, and courses in economics were taught in law schools. . . .

The Austrian School was also bound together through family and social ties: [his two leading disciples, [Eugen von] Böhm-Bawerk and Friedrich von Wieser [were brothers-in-law]. [Wieser was] a close friend of the statistician Franz von Juraschek, Friedrich Hayek’s maternal grandfather. Young Austrian economists bonded on Alpine excursions and met in Böhm-Bawerk’s famous seminars (also attended by the Bolshevik Nikolai Bukharin and the German Marxist Rudolf Hilferding). Ludwig von Mises continued this tradition, holding private seminars in Vienna in the 1920s and later in New York. As Wasserman notes, the Austrian School was “a social network first and last.”

After World War I, the Habsburg Empire was dismantled by the victorious Allies. The Austrian bureaucracy shrank, and university placements became scarce. Menger, the last surviving member of the first generation of Austrian economists, died in 1921. The economic school he founded, with its emphasis on individualism and free markets, might have disappeared under the socialism of “Red Vienna.” Instead, a new generation of brilliant young economists emerged: Schumpeter, Hayek, and Mises—all of whom published best-selling works in English and remain familiar names today—along with a number of less well known but influential economists, including Oskar Morgenstern, Fritz Machlup, Alexander Gerschenkron, and Gottfried Haberler.

Two factual corrections are in order. Menger outlived Böhm-Bawerk, but not his other chief disciple von Wieser, who died in 1926, not long after supervising Hayek’s doctoral dissertation, later published in 1927, and, in 1933, translated into English and published as Monetary Theory and the Trade Cycle. Moreover, a 16-year gap separated Mises and Schumpeter, who were exact contemporaries, from Hayek (born in 1899) who was a few years older than Gerschenkron, Haberler, Machlup and Morgenstern.

All the surviving members or associates of the Austrian school wound up either in the US or Britain after World War II, and Hayek, who had taken a position in London in 1931, moved to the US in 1950, taking a position in the Committee on Social Thought at the University of Chicago after having been refused a position in the economics department. Through the intervention of wealthy sponsors, Mises obtained an academic appointment of sorts at the NYU economics department, where he succeeded in training two noteworthy disciples who wrote dissertations under his tutelage, Murray Rothbard and Israel Kirzner. (Kirzner wrote his dissertation under Mises at NYU, but Rothbard did his graduate work at Colulmbia.) Schumpeter, Haberler and Gerschenkron eventually took positions at Harvard, while Machlup (with some stops along the way) and Morgenstern made their way to Princeton. However, Hayek’s interests shifted from pure economic theory to deep philosophical questions. While Machlup and Haberler continued to work on economic theory, the Austrian influence on their work after World War II was barely recognizable. Morgenstern and Schumpeter made major contributions to economics, but did not hide their alienation from the doctrines of the Austrian School.

So there was little reason to expect that the Austrian School would survive its dispersal when the Nazis marched unopposed into Vienna in 1938. That it did survive is in no small measure due to its ideological usefulness to anti-socialist supporters who provided financial support to Hayek, enabling his appointment to the Committee on Social Thought at the University of Chicago, and Mises’s appointment at NYU, and other forms of research support to Hayek, Mises and other like-minded scholars, as well as funding the Mont Pelerin Society, an early venture in globalist networking, started by Hayek in 1947. Such support does not discredit the research to which it gave rise. That the survival of the Austrian School would probably not have been possible without the support of wealthy benefactors who anticipated that the Austrians would advance their political and economic interests does not invalidate the research thereby enabled. (In the interest of transparency, I acknowledge that I received support from such sources for two books that I wrote.)

Because Austrian School survivors other than Mises and Hayek either adapted themselves to mainstream thinking without renouncing their earlier beliefs (Haberler and Machlup) or took an entirely different direction (Morgenstern), and because the economic mainstream shifted in two directions that were most uncongenial to the Austrians: Walrasian general-equilibrium theory and Keynesian macroeconomics, the Austrian remnant, initially centered on Mises at NYU, adopted a sharply adversarial attitude toward mainstream economic doctrines.

Despite its minute numbers, the lonely remnant became a house divided against itself, Mises’s two outstanding NYU disciples, Murray Rothbard and Israel Kirzner, holding radically different conceptions of how to carry on the Austrian tradition. An extroverted radical activist, Rothbard was not content just to lead a school of economic thought, he aspired to become the leader of a fantastical anarchistic revolutionary movement to replace all established governments under a reign of private-enterprise anarcho-capitalism. Rothbard’s political radicalism, which, despite his Jewish ancestry, even included dabbling in Holocaust denialism, so alienated his mentor, that Mises terminated all contact with Rothbard for many years before his death. Kirzner, self-effacing, personally conservative, with no political or personal agenda other than the advancement of his own and his students’ scholarship, published hundreds of articles and several books filling 10 thick volumes of his collected works published by the Liberty Fund, while establishing a robust Austrian program at NYU, training many excellent scholars who found positions in respected academic and research institutions. Similar Austrian programs, established under the guidance of Kirzner’s students, were started at other institutions, most notably at George Mason University.

One of the founders of the Cato Institute, which for nearly half a century has been the leading avowedly libertarian think tank in the US, Rothbard was eventually ousted by Cato, and proceeded to set up a rival think tank, the Ludwig von Mises Institute, at Auburn University, which has turned into a focal point for extreme libertarians and white nationalists to congregate, get acquainted, and strategize together.

Isolation and marginalization tend to cause a subspecies either to degenerate toward extinction, to somehow blend in with the members of the larger species, thereby losing its distinctive characteristics, or to accentuate its unique traits, enabling it to find some niche within which to survive as a distinct sub-species. Insofar as they have engaged in economic analysis rather than in various forms of political agitation and propaganda, the Rothbardian Austrians have focused on anarcho-capitalist theory and the uniquely perverse evils of fractional-reserve banking.

Rejecting the political extremism of the Rothbardians, Kirznerian Austrians differentiate themselves by analyzing what they call market processes and emphasizing the limitations on the knowledge and information possessed by actual decision-makers. They attribute this misplaced focus on equilibrium to the extravagantly unrealistic and patently false assumptions of mainstream models on the knowledge possessed by economic agents, which effectively make equilibrium the inevitable — and trivial — conclusion entailed by those extreme assumptions. In their view, the focus of mainstream models on equilibrium states with unrealistic assumptions results from a preoccupation with mathematical formalism in which mathematical tractability rather than sound economics dictates the choice of modeling assumptions.

Skepticism of the extreme assumptions about the informational endowments of agents covers a range of now routine assumptions in mainstream models, e.g., the ability of agents to form precise mathematical estimates of the probability distributions of future states of the world, implying that agents never confront decisions about which they are genuinely uncertain. Austrians also object to the routine assumption that all the information needed to determine the solution of a model is the common knowledge of the agents in the model, so that an existing equilibrium cannot be disrupted unless new information randomly and unpredictably arrives. Each agent in the model having been endowed with the capacity of a semi-omniscient central planner, solving the model for its equilibrium state becomes a trivial exercise in which the optimal choices of a single agent are taken as representative of the choices made by all of the model’s other, semi-omnicient, agents.

Although shreds of subjectivism — i.e., agents make choices based own preference orderings — are shared by all neoclassical economists, Austrian criticisms of mainstream neoclassical models are aimed at what Austrians consider to be their insufficient subjectivism. It is this fierce commitment to a robust conception of subjectivism, in which an equilibrium state of shared expectations by economic agents must be explained, not just assumed, that Chancellor properly identifies as a distinguishing feature of the Austrian School.

Menger’s original idea of marginal utility was posited on the subjective preferences of consumers. This subjectivist position was retained by subsequent generations of the school. It inspired a tradition of radical individualism, which in time made the Austrians the favorite economists of American libertarians. Subjectivism was at the heart of the Austrians’ polemical rejection of Marxism. Not only did they dismiss Marx’s labor theory of value, they argued that socialism couldn’t possibly work since it would lack the means to allocate resources efficiently.

The problem with central planning, according to Hayek, is that so much of the knowledge that people act upon is specific knowledge that individuals acquire in the course of their daily activities and life experience, knowledge that is often difficult to articulate – mere intuition and guesswork, yet more reliable than not when acted upon by people whose livelihoods depend on being able to do the right thing at the right time – much less communicate to a central planner.

Chancellor attributes Austrian mistrust of statistical aggregates or indices, like GDP and price levels, to Austrian subjectivism, which regards such magnitudes as abstractions irrelevant to the decisions of private decision-makers, except perhaps in forming expectations about the actions of government policy makers. (Of course, this exception potentially provides full subjectivist license and legitimacy for macroeconomic theorizing despite Austrian misgivings.) Observed statistical correlations between aggregate variables identified by macroeconomists are dismissed as irrelevant unless grounded in, and implied by, the purposeful choices of economic agents.

But such scruples about the use of macroeconomic aggregates and inferring causal relationships from observed correlations are hardly unique to the Austrian school. One of the most important contributions of the 20th century to the methodology of economics was an article by T. C. Koopmans, “Measurement Without Theory,” which argued that measured correlations between macroeconomic variables provide a reliable basis for business-cycle research and policy advice only if the correlations can be explained in terms of deeper theoretical or structural relationships. The Nobel Prize Committee, in awarding the 1975 Prize to Koopmans, specifically mentioned this paper in describing Koopmans’s contributions. Austrians may be more fastidious than their mainstream counterparts in rejecting macroeconomic relationships not based on microeconomic principles, but they aren’t the only ones mistrustful of mere correlations.

Chancellor cites mistrust about the use of statistical aggregates and price indices as a factor in Hayek’s disastrous policy advice warning against anti-deflationary or reflationary measures during the Great Depression.

Their distrust of price indexes brought Austrian economists into conflict with mainstream economic opinion during the 1920s. At the time, there was a general consensus among leading economists, ranging from Irving Fisher at Yale to Keynes at Cambridge, that monetary policy should aim at delivering a stable price level, and in particular seek to prevent any decline in prices (deflation). Hayek, who earlier in the decade had spent time at New York University studying monetary policy and in 1927 became the first director of the Austrian Institute for Business Cycle Research, argued that the policy of price stabilization was misguided. It was only natural, Hayek wrote, that improvements in productivity should lead to lower prices and that any resistance to this movement (sometimes described as “good deflation”) would have damaging economic consequences.

The argument that deflation stemming from economic expansion and increasing productivity is normal and desirable isn’t what led Hayek and the Austrians astray in the Great Depression; it was their failure to realize the deflation that triggered the Great Depression was a monetary phenomenon caused by a malfunctioning international gold standard. Moreover, Hayek’s own business-cycle theory explicitly stated that a neutral (stable) monetary policy ought to aim at keeping the flow of total spending and income constant in nominal terms while his policy advice of welcoming deflation meant a rapidly falling rate of total spending. Hayek’s policy advice was an inexcusable error of judgment, which, to his credit, he did acknowledge after the fact, though many, perhaps most, Austrians have refused to follow him even that far.

Considered from the vantage point of almost a century, the collapse of the Austrian School seems to have been inevitable. Hayek’s long-shot bid to establish his business-cycle theory as the dominant explanation of the Great Depression was doomed from the start by the inadequacies of the very specific version of his basic model and his disregard of the obvious implication of that model: prevent total spending from contracting. The promising young students and colleagues who had briefly gathered round him upon his arrival in England, mostly attached themselves to other mentors, leaving Hayek with only one or two immediate disciples to carry on his research program. The collapse of his research program, which he himself abandoned after completing his final work in economic theory, marked a research hiatus of almost a quarter century, with the notable exception of publications by his student, Ludwig Lachmann who, having decamped in far-away South Africa, labored in relative obscurity for most of his career.

The early clash between Keynes and Hayek, so important in the eyes of Chancellor and others, is actually overrated. Chancellor, quoting Lachmann and Nicholas Wapshott, describes it as a clash of two irreconcilable views of the economic world, and the clash that defined modern economics. In later years, Lachmann actually sought to effect a kind of reconciliation between their views. It was not a conflict of visions that undid Hayek in 1931-32, it was his misapplication of a narrowly constructed model to a problem for which it was irrelevant.

Although the marginalization of the Austrian School, after its misguided policy advice in the Great Depression and its dispersal during and after World War II, is hardly surprising, the unwillingness of mainstream economists to sort out what was useful and relevant in the teachings of the Austrian School from what is not was unfortunate not only for the Austrians. Modern economics was itself impoverished by its disregard for the complexity and interconnectedness of economic phenomena. It’s precisely the Austrian attentiveness to the complexity of economic activity — the necessity for complementary goods and factors of production to be deployed over time to satisfy individual wants – that is missing from standard economic models.

That Austrian attentiveness, pioneered by Menger himself, to the complementarity of inputs applied over the course of time undoubtedly informed Hayek’s seminal contribution to economic thought: his articulation of the idea of intertemporal equilibrium that comprehends the interdependence of the plans of independent agents and the need for them to all fit together over the course of time for equilibrium to obtain. Hayek’s articulation represented a conceptual advance over earlier versions of equilibrium analysis stemming from Walras and Pareto, and even from Irving Fisher who did pay explicit attention to intertemporal equilibrium. But in Fisher’s articulation, intertemporal consistency was described in terms of aggregate production and income, leaving unexplained the mechanisms whereby the individual plans to produce and consume particular goods over time are reconciled. Hayek’s granular exposition enabled him to attend to, and articulate, necessary but previously unspecified relationships between the current prices and expected future prices.

Moreover, neither mainstream nor Austrian economists have ever explained how prices are adjust in non-equilibrium settings. The focus of mainstream analysis has always been the determination of equilibrium prices, with the implicit understanding that “market forces” move the price toward its equilibrium value. The explanatory gap has been filled by the mainstream New Classical School which simply posits the existence of an equilibrium price vector, and, to replace an empirically untenable tâtonnement process for determining prices, posits an equally untenable rational-expectations postulate to assert that market economies typically perform as if they are in, or near the neighborhood of, equilibrium, so that apparent fluctuations in real output are viewed as optimal adjustments to unexplained random productivity shocks.

Alternatively, in New Keynesian mainstream versions, constraints on price changes prevent immediate adjustments to rationally expected equilibrium prices, leading instead to persistent reductions in output and employment following demand or supply shocks. (I note parenthetically that the assumption of rational expectations is not, as often suggested, an assumption distinct from market-clearing, because the rational expectation of all agents of a market-clearing price vector necessarily implies that the markets clear unless one posits a constraint, e.g., a binding price floor or ceiling, that prevents all mutually beneficial trades from being executed.)

Similarly, the Austrian school offers no explanation of how unconstrained price adjustments by market participants is a sufficient basis for a systemic tendency toward equilibrium. Without such an explanation, their belief that market economies have strong self-correcting properties is unfounded, because, as Hayek demonstrated in his 1937 paper, “Economics and Knowledge,” price adjustments in current markets don’t, by themselves, ensure a systemic tendency toward equilibrium values that coordinate the plans of independent economic agents unless agents’ expectations of future prices are sufficiently coincident. To take only one passage of many discussing the difficulty of explaining or accounting for a process that leads individuals toward a state of equilibrium, I offer the following as an example:

All that this condition amounts to, then, is that there must be some discernible regularity in the world which makes it possible to predict events correctly. But, while this is clearly not sufficient to prove that people will learn to foresee events correctly, the same is true to a hardly less degree even about constancy of data in an absolute sense. For any one individual, constancy of the data does in no way mean constancy of all the facts independent of himself, since, of course, only the tastes and not the actions of the other people can in this sense be assumed to be constant. As all those other people will change their decisions as they gain experience about the external facts and about other people’s actions, there is no reason why these processes of successive changes should ever come to an end. These difficulties are well known, and I mention them here only to remind you how little we actually know about the conditions under which an equilibrium will ever be reached.

In this theoretical muddle, Keynesian economics and the neoclassical synthesis were abandoned, because the key proposition of Keynesian economics was supposedly the tendency of a modern economy toward an equilibrium with involuntary unemployment while the neoclassical synthesis rejected that proposition, so that the supposed synthesis was no more than an agreement to disagree. That divided house could not stand. The inability of Keynesian economists such as Hicks, Modigliani, Samuelson and Patinkin to find a satisfactory (at least in terms of a preferred Walrasian general-equilibrium model) rationalization for Keynes’s conclusion that an economy would likely become stuck in an equilibrium with involuntary unemployment led to the breakdown of the neoclassical synthesis and the displacement of Keynesianism as the dominant macroeconomic paradigm.

But perhaps the way out of the muddle is to abandon the idea that a systemic tendency toward equilibrium is a property of an economic system, and, instead, to recognize that equilibrium is, as Hayek suggested, a contingent, not a necessary, property of a complex economy. Ludwig Lachmann, cited by Chancellor for his remark that the early theoretical clash between Hayek and Keynes was a conflict of visions, eventually realized that in an important sense both Hayek and Keynes shared a similar subjectivist conception of the crucial role of individual expectations of the future in explaining the stability or instability of market economies. And despite the efforts of New Classical economists to establish rational expectations as an axiomatic equilibrating property of market economies, that notion rests on nothing more than arbitrary methodological fiat.

Chancellor concludes by suggesting that Wasserman’s characterization of the Austrians as marginalized is not entirely accurate inasmuch as “the Austrians’ view of the economy as a complex, evolving system continues to inspire new research.” Indeed, if economics is ever to find a way out of its current state of confusion, following Lachmann in his quest for a synthesis of sorts between Keynes and Hayek might just be a good place to start from.

What’s Wrong with DSGE Models Is Not Representative Agency

The basic DSGE macroeconomic model taught to students is based on a representative agent. Many critics of modern macroeconomics and DSGE models have therefore latched on to the representative agent as the key – and disqualifying — feature in DSGE models, and by extension, with modern macroeconomics. Criticism of representative-agent models is certainly appropriate, because, as Alan Kirman admirably explained some 25 years ago, the simplification inherent in a macoreconomic model based on a representative agent, renders the model entirely inappropriate and unsuitable for most of the problems that a macroeconomic model might be expected to address, like explaining why economies might suffer from aggregate fluctuations in output and employment and the price level.

While altogether fitting and proper, criticism of the representative agent model in macroeconomics had an unfortunate unintended consequence, which was to focus attention on representative agency rather than on the deeper problem with DSGE models, problems that cannot be solved by just throwing the Representative Agent under the bus.

Before explaining why representative agency is not the root problem with DSGE models, let’s take a moment or two to talk about where the idea of representative agency comes from. The idea can be traced back to F. Y. Edgeworth who, in his exposition of the ideas of W. S. Jevons – one of the three marginal revolutionaries of the 1870s – introduced two “representative particulars” to illustrate how trade could maximize the utility of each particular subject to the benchmark utility of the counterparty. That analysis of two different representative particulars, reflected in what is now called the Edgeworth Box, remains one of the outstanding achievements and pedagogical tools of economics. (See a superb account of the historical development of the Box and the many contributions to economic theory that it facilitated by Thomas Humphrey). But Edgeworth’s analysis and its derivatives always focused on the incentives of two representative agents rather than a single isolated representative agent.

Only a few years later, Alfred Marshall in his Principles of Economics, offered an analysis of how the equilibrium price for the product of a competitive industry is determined by the demand for (derived from the marginal utility accruing to consumers from increments of the product) and the supply of that product (derived from the cost of production). The concepts of the marginal cost of an individual firm as a function of quantity produced and the supply of an individual firm as a function of price not yet having been formulated, Marshall, in a kind of hand-waving exercise, introduced a hypothetical representative firm as a stand-in for the entire industry.

The completely ad hoc and artificial concept of a representative firm was not well-received by Marshall’s contemporaries, and the young Lionel Robbins, starting his long career at the London School of Economics, subjected the idea to withering criticism in a 1928 article. Even without Robbins’s criticism, the development of the basic theory of a profit-maximizing firm quickly led to the disappearance of Marshall’s concept from subsequent economics textbooks. James Hartley wrote about the short and unhappy life of Marshall’s Representative Firm in the Journal of Economic Perspectives.

One might have thought that the inauspicious career of Marshall’s Representative Firm would have discouraged modern macroeconomists from resurrecting the Representative Firm in the barely disguised form of a Representative Agent in their DSGE models, but the convenience and relative simplicity of solving a DSGE model for a single agent was too enticing to be resisted.

Therein lies the difference between the theory of the firm and a macroeconomic theory. The gain in convenience from adopting the Representative Firm was radically reduced by Marshall’s Cambridge students and successors who, without the representative firm, provided a more rigorous, more satisfying and more flexible exposition of the industry supply curve and the corresponding partial-equilibrium analysis than Marshall had with it. Providing no advantages of realism, logical coherence, analytical versatility or heuristic intuition, the Representative Firm was unceremoniously expelled from the polite company of economists.

However, as a heuristic device for portraying certain properties of an equilibrium state — whose existence is assumed not derived — even a single representative individual or agent proved to be a serviceable device with which to display the defining first-order conditions, the simultaneous equality of marginal rates of substitution in consumption and production with the marginal rate of substitution at market prices. Unlike the Edgeworth Box populated by two representative agents whose different endowments or preference maps result in mutually beneficial trade, the representative agent, even if afforded the opportunity to trade, can find no gain from engaging in it.

An excellent example of this heuristic was provided by Jack Hirshleifer in his 1970 textbook Investment, Interest, and Capital, wherein he adapted the basic Fisherian model of intertemporal consumption, production and exchange opportunities, representing the canonical Fisherian exposition in a single basic diagram. But the representative agent necessarily represents a state of no trade, because, for a single isolated agent, production and consumption must coincide, and the equilibrium price vector must have the property that the representative agent chooses not to trade at that price vector. I reproduce Hirshleifer’s diagram (Figure 4-6) in the attached chart.

Here is how Hirshleifer explained what was going on.

Figure 4-6 illustrates a technique that will be used often from now on: the representative-individual device. If one makes the assumption that all individuals have identical tastes and are identically situated with respect to endowments and productive opportunities, it follows that the individual optimum must be a microcosm of the social equilibrium. In this model the productive and consumptive solutions coincide, as in the Robinson Crusoe case. Nevertheless, market opportunities exist, as indicated by the market line M’M’ through the tangency point P* = C*. But the price reflected in the slope of M’M’ is a sustaining price, such that each individual prefers to hold the combination attained by productive transformations rather than engage in market transactions. The representative-individual device is helpful in suggesting how the equilibrium will respond to changes in exogenous data—the proviso being that such changes od not modify the distribution of wealth among individuals.

While not spelling out the limitations of the representative-individual device, Hirshleifer makes it clear that the representative-agent device is being used as an expository technique to describe, not as an analytical tool to determine, intertemporal equilibrium. The existence of intertemporal equilibrium does not depend on the assumptions necessary to allow a representative individual to serve as a stand-in for all other agents. The representative-individual is portrayed only to provide the student with a special case serving as a visual aid with which to gain an intuitive grasp of the necessary conditions characterizing an intertemporal equilibrium in production and consumption.

But the role of the representative agent in the DSGE model is very different from the representative individual in Hirshleifer’s exposition of the canonical Fisherian theory. In Hirshleifer’s exposition, the representative individual is just a special case and a visual aid with no independent analytical importance. In contrast to Hirshleifer’s deployment of the representative-individual, representative-agent in the DSGE model is used as an assumption whereby an analytical solution to the DSGE model can be derived, allowing the modeler to generate quantitative results to be compared with existing time-series data, to generate forecasts of future economic conditions, and to evaluate the effects of alternative policy rules.

The prominent and dubious role of the representative agent in DSGE models provided a convenient target for critics of DSGE models to direct their criticisms. In Congressional testimony, Robert Solow famously attacked DSGE models and used their reliance on the representative-agents to make them seem, well, simply ridiculous.

Most economists are willing to believe that most individual “agents” – consumers investors, borrowers, lenders, workers, employers – make their decisions so as to do the best that they can for themselves, given their possibilities and their information. Clearly they do not always behave in this rational way, and systematic deviations are well worth studying. But this is not a bad first approximation in many cases. The DSGE school populates its simplified economy – remember that all economics is about simplified economies just as biology is about simplified cells – with exactly one single combination worker-owner-consumer-everything-else who plans ahead carefully and lives forever. One important consequence of this “representative agent” assumption is that there are no conflicts of interest, no incompatible expectations, no deceptions.

This all-purpose decision-maker essentially runs the economy according to its own preferences. Not directly, of course: the economy has to operate through generally well-behaved markets and prices. Under pressure from skeptics and from the need to deal with actual data, DSGE modellers have worked hard to allow for various market frictions and imperfections like rigid prices and wages, asymmetries of information, time lags, and so on. This is all to the good. But the basic story always treats the whole economy as if it were like a person, trying consciously and rationally to do the best it can on behalf of the representative agent, given its circumstances. This cannot be an adequate description of a national economy, which is pretty conspicuously not pursuing a consistent goal. A thoughtful person, faced with the thought that economic policy was being pursued on this basis, might reasonably wonder what planet he or she is on.

An obvious example is that the DSGE story has no real room for unemployment of the kind we see most of the time, and especially now: unemployment that is pure waste. There are competent workers, willing to work at the prevailing wage or even a bit less, but the potential job is stymied by a market failure. The economy is unable to organize a win-win situation that is apparently there for the taking. This sort of outcome is incompatible with the notion that the economy is in rational pursuit of an intelligible goal. The only way that DSGE and related models can cope with unemployment is to make it somehow voluntary, a choice of current leisure or a desire to retain some kind of flexibility for the future or something like that. But this is exactly the sort of explanation that does not pass the smell test.

While Solow’s criticism of the representative agent was correct, he left himself open to an effective rejoinder by defenders of DSGE models who could point out that the representative agent was adopted by DSGE modelers not because it was an essential feature of the DSGE model but because it enabled DSGE modelers to simplify the task of analytically solving for an equilibrium solution. With enough time and computing power, however, DSGE modelers were able to write down models with a few heterogeneous agents (themselves representative of particular kinds of agents in the model) and then crank out an equilibrium solution for those models.

Unfortunately for Solow, V. V. Chari also testified at the same hearing, and he responded directly to Solow, denying that DSGE models necessarily entail the assumption of a representative agent and identifying numerous examples even in 2010 of DSGE models with heterogeneous agents.

What progress have we made in modern macro? State of the art models in, say, 1982, had a representative agent, no role for unemployment, no role for Financial factors, no sticky prices or sticky wages, no role for crises and no role for government. What do modern macroeconomic models look like? The models have all kinds of heterogeneity in behavior and decisions. This heterogeneity arises because people’s objectives dier, they differ by age, by information, by the history of their past experiences. Please look at the seminal work by Rao Aiyagari, Per Krusell and Tony Smith, Tim Kehoe and David Levine, Victor Rios Rull, Nobu Kiyotaki and John Moore. All of them . . . prominent macroeconomists at leading departments . . . much of their work is explicitly about models without representative agents. Any claim that modern macro is dominated by representative-agent models is wrong.

So on the narrow question of whether DSGE models are necessarily members of the representative-agent family, Solow was debunked by Chari. But debunking the claim that DSGE models must be representative-agent models doesn’t mean that DSGE models have the basic property that some of us at least seek in a macro-model: the capacity to explain how and why an economy may deviate from a potential full-employment time path.

Chari actually addressed the charge that DSGE models cannot explain lapses from full employment (to use Pigou’s rather anodyne terminology for depressions). Here is Chari’s response:

In terms of unemployment, the baseline model used in the analysis of labor markets in modern macroeconomics is the Mortensen-Pissarides model. The main point of this model is to focus on the dynamics of unemployment. It is specifically a model in which labor markets are beset with frictions.

Chari’s response was thus to treat lapses from full employment as “frictions.” To treat unemployment as the result of one or more frictions is to take a very narrow view of the potential causes of unemployment. The argument that Keynes made in the General Theory was that unemployment is a systemic failure of a market economy, which lacks an error-correction mechanism that is capable of returning the economy to a full-employment state, at least not within a reasonable period of time.

The basic approach of DSGE is to treat the solution of the model as an optimal solution of a problem. In the representative-agent version of a DSGE model, the optimal solution is optimal solution for a single agent, so optimality is already baked into the model. With heterogeneous agents, the solution of the model is a set of mutually consistent optimal plans, and optimality is baked into that heterogenous-agent DSGE model as well. Sophisticated heterogeneous-agent models can incorporate various frictions and constraints that cause the solution to deviate from a hypothetical frictionless, unconstrained first-best optimum.

The policy message emerging from this modeling approach is that unemployment is attributable to frictions and other distortions that don’t permit a first-best optimum that would be achieved automatically in their absence from being reached. The possibility that the optimal plans of individuals might be incompatible resulting in a systemic breakdown — that there could be a failure to coordinate — does not even come up for discussion.

One needn’t accept Keynes’s own theoretical explanation of unemployment to find the attribution of cyclical unemployment to frictions deeply problematic. But, as I have asserted in many previous posts (e.g., here and here) a modeling approach that excludes a priori any systemic explanation of cyclical unemployment, attributing instead all cyclical unemployment to frictions or inefficient constraints on market pricing, cannot be regarded as anything but an exercise in question begging.

 

Phillips Curve Musings: Second Addendum on Keynes and the Rate of Interest

In my two previous posts (here and here), I have argued that the partial-equilibrium analysis of a single market, like the labor market, is inappropriate and not particularly relevant, in situations in which the market under analysis is large relative to other markets, and likely to have repercussions on those markets, which, in turn, will have further repercussions on the market under analysis, violating the standard ceteris paribus condition applicable to partial-equilibrium analysis. When the standard ceteris paribus condition of partial equilibrium is violated, as it surely is in analyzing the overall labor market, the analysis is, at least, suspect, or, more likely, useless and misleading.

I suggested that Keynes in chapter 19 of the General Theory was aiming at something like this sort of argument, and I think he was largely right in his argument. But, in all modesty, I think that Keynes would have done better to have couched his argument in terms of the distinction between partial-equilibrium and general-equilibrium analysis. But his Marshallian training, which he simultaneously embraced and rejected, may have made it difficult for him to adopt the Walrasian general-equilibrium approach that Marshall and the Marshallians regarded as overly abstract and unrealistic.

In my next post, I suggested that the standard argument about the tendency of public-sector budget deficits to raise interest rates by competing with private-sector borrowers for loanable funds is fundamentally misguided, because it, too, inappropriately applies the partial-equilibrium analysis of a narrow market for government securities, or even a more broadly defined market for loanable funds in general.

That is a gross mistake, because the rate of interest is determined in a general-equilibrium system along with markets for all long-lived assets, embodying expected flows of income that must be discounted to the present to determine an estimated present value. Some assets are riskier than others and that risk is reflected in those valuations. But the rate of interest is distilled from the combination of all of those valuations, not prior to, or apart from, those valuations. Interest rates of different duration and different risk are embeded in the entire structure of current and expected prices for all long-lived assets. To focus solely on a very narrow subset of markets for newly issued securities, whose combined value is only a small fraction of the total value of all existing long-lived assets, is to miss the forest for the trees.

What I want to point out in this post is that Keynes, whom I credit for having recognized that partial-equilibrium analysis is inappropriate and misleading when applied to an overall market for labor, committed exactly the same mistake that he condemned in the context of the labor market, by asserting that the rate of interest is determined in a single market: the market for money. According to Keynes, the market rate of interest is that rate which equates the stock of money in existence with the amount of money demanded by the public. The higher the rate of interest, Keynes argued, the less money the public wants to hold.

Keynes, applying the analysis of Marshall and his other Cambridge predecessors, provided a wonderful analysis of the factors influencing the amount of money that people want to hold (usually expressed in terms of a fraction of their income). However, as superb as his analysis of the demand for money was, it was a partial-equilibrium analysis, and there was no recognition on his part that other markets in the economy are influenced by, and exert influence upon, the rate of interest.

What makes Keynes’s partial-equilibrium analysis of the interest rate so difficult to understand is that in chapter 17 of the General Theory, a magnificent tour de force of verbal general-equilibrium theorizing, explained the relationships that must exist between the expected returns for alternative long-lived assets that are held in equilibrium. Yet, disregarding his own analysis of the equilibrium relationship between returns on alternative assets, Keynes insisted on explaining the rate of interest in a one-period model (a model roughly corresponding to IS-LM) with only two alternative assets: money and bonds, but no real capital asset.

A general-equilibrium analysis of the rate of interest ought to have at least two periods, and it ought to have a real capital good that may be held in the present for use or consumption in the future, a possibility entirely missing from the Keynesian model. I have discussed this major gap in the Keynesian model in a series of posts (here, here, here, here, and here) about Earl Thompson’s 1976 paper “A Reformulation of Macroeconomic Theory.”

Although Thompson’s model seems to me too simple to account for many macroeconomic phenomena, it would have been a far better starting point for the development of macroeconomics than any of the models from which modern macroeconomic theory has evolved.

Price Stickiness Is a Symptom not a Cause

In my recent post about Nick Rowe and the law of reflux, I mentioned in passing that I might write a post soon about price stickiness. The reason that I thought it would be worthwhile writing again about price stickiness (which I have written about before here and here), because Nick, following a broad consensus among economists, identifies price stickiness as a critical cause of fluctuations in employment and income. Here’s how Nick phrased it:

An excess demand for land is observed in the land market. An excess demand for bonds is observed in the bond market. An excess demand for equities is observed in the equity market. An excess demand for money is observed in any market. If some prices adjust quickly enough to clear their market, but other prices are sticky so their markets don’t always clear, we may observe an excess demand for money as an excess supply of goods in those sticky-price markets, but the prices in flexible-price markets will still be affected by the excess demand for money.

Then a bit later, Nick continues:

If individuals want to save in the form of money, they won’t collectively be able to if the stock of money does not increase.There will be an excess demand for money in all the money markets, except those where the price of the non-money thing in that market is flexible and adjusts to clear that market. In the sticky-price markets there will nothing an individual can do if he wants to buy more money but nobody else wants to sell more. But in those same sticky-price markets any individual can always sell less money, regardless of what any other individual wants to do. Nobody can stop you selling less money, if that’s what you want to do.

Unable to increase the flow of money into their portfolios, each individual reduces the flow of money out of his portfolio. Demand falls in stick-price markets, quantity traded is determined by the short side of the market (Q=min{Qd,Qs}), so trade falls, and some traders that would be mutually advantageous in a barter or Walrasian economy even at those sticky prices don’t get made, and there’s a recession. Since money is used for trade, the demand for money depends on the volume of trade. When trade falls the flow of money falls too, and the stock demand for money falls, until the representative individual chooses a flow of money out of his portfolio equal to the flow in. He wants to increase the flow in, but cannot, since other individuals don’t want to increase their flows out.

The role of price stickiness or price rigidity in accounting for involuntary unemployment is an old and complicated story. If you go back and read what economists before Keynes had to say about the Great Depression, you will find that there was considerable agreement that, in principle, if workers were willing to accept a large enough cut in their wages, they could all get reemployed. That was a proposition accepted by Hawtry and by Keynes. However, they did not believe that wage cutting was a good way of restoring full employment, because the process of wage cutting would be brutal economically and divisive – even self-destructive – politically. So they favored a policy of reflation that would facilitate and hasten the process of recovery. However, there also those economists, e.g., Ludwig von Mises and the young Lionel Robbins in his book The Great Depression, (which he had the good sense to disavow later in life) who attributed high unemployment to an unwillingness of workers and labor unions to accept wage cuts and to various other legal barriers preventing the price mechanism from operating to restore equilibrium in the normal way that prices adjust to equate the amount demanded with the amount supplied in each and every single market.

But in the General Theory, Keynes argued that if you believed in the standard story told by microeconomics about how prices constantly adjust to equate demand and supply and maintain equilibrium, then maybe you should be consistent and follow the Mises/Robbins story and just wait for the price mechanism to perform its magic, rather than support counter-cyclical monetary and fiscal policies. So Keynes then argued that there is actually something wrong with the standard microeconomic story; price adjustments can’t ensure that overall economic equilibrium is restored, because the level of employment depends on aggregate demand, and if aggregate demand is insufficient, wage cutting won’t increase – and, more likely, would reduce — aggregate demand, so that no amount of wage-cutting would succeed in reducing unemployment.

To those upholding the idea that the price system is a stable self-regulating system or process for coordinating a decentralized market economy, in other words to those upholding microeconomic orthodoxy as developed in any of the various strands of the neoclassical paradigm, Keynes’s argument was deeply disturbing and subversive.

In one of the first of his many important publications, “Liquidity Preference and the Theory of Money and Interest,” Franco Modigliani argued that, despite Keynes’s attempt to prove that unemployment could persist even if prices and wages were perfectly flexible, the assumption of wage rigidity was in fact essential to arrive at Keynes’s result that there could be an equilibrium with involuntary unemployment. Modigliani did so by positing a model in which the supply of labor is a function of real wages. It was not hard for Modigliani to show that in such a model an equilibrium with unemployment required a rigid real wage.

Modigliani was not in favor of relying on price flexibility instead of counter-cyclical policy to solve the problem of involuntary unemployment; he just argued that the rationale for such policies had to be that prices and wages were not adjusting immediately to clear markets. But the inference that Modigliani drew from that analysis — that price flexibility would lead to an equilibrium with full employment — was not valid, there being no guarantee that price adjustments would necessarily lead to equilibrium, unless all prices and wages instantaneously adjusted to their new equilibrium in response to any deviation from a pre-existing equilibrium.

All the theory of general equilibrium tells us is that if all trading takes place at the equilibrium set of prices, the economy will be in equilibrium as long as the underlying “fundamentals” of the economy do not change. But in a decentralized economy, no one knows what the equilibrium prices are, and the equilibrium price in each market depends in principle on what the equilibrium prices are in every other market. So unless the price in every market is an equilibrium price, none of the markets is necessarily in equilibrium.

Now it may well be that if all prices are close to equilibrium, the small changes will keep moving the economy closer and closer to equilibrium, so that the adjustment process will converge. But that is just conjecture, there is no proof showing the conditions under which a simple rule that says raise the price in any market with an excess demand and decrease the price in any market with an excess supply will in fact lead to the convergence of the whole system to equilibrium. Even in a Walrasian tatonnement system, in which no trading at disequilibrium prices is allowed, there is no proof that the adjustment process will eventually lead to the discovery of the equilibrium price vector. If trading at disequilibrium prices is allowed, tatonnement is hopeless.

So the real problem is not that prices are sticky but that trading takes place at disequilibrium prices and there is no mechanism by which to discover what the equilibrium prices are. Modern macroeconomics solves this problem, in its characteristic fashion, by assuming it away by insisting that expectations are “rational.”

Economists have allowed themselves to make this absurd assumption because they are in the habit of thinking that the simple rule of raising price when there is an excess demand and reducing the price when there is an excess supply inevitably causes convergence to equilibrium. This habitual way of thinking has been inculcated in economists by the intense, and largely beneficial, training they have been subjected to in Marshallian partial-equilibrium analysis, which is built on the assumption that every market can be analyzed in isolation from every other market. But that analytic approach can only be justified under a very restrictive set of assumptions. In particular it is assumed that any single market under consideration is small relative to the whole economy, so that its repercussions on other markets can be ignored, and that every other market is in equilibrium, so that there are no changes from other markets that are impinging on the equilibrium in the market under consideration.

Neither of these assumptions is strictly true in theory, so all partial equilibrium analysis involves a certain amount of hand-waving. Nor, even if we wanted to be careful and precise, could we actually dispense with the hand-waving; the hand-waving is built into the analysis, and can’t be avoided. I have often referred to these assumptions required for the partial-equilibrium analysis — the bread and butter microeconomic analysis of Econ 101 — to be valid as the macroeconomic foundations of microeconomics, by which I mean that the casual assumption that microeconomics somehow has a privileged and secure theoretical position compared to macroeconomics and that macroeconomic propositions are only valid insofar as they can be reduced to more basic microeconomic principles is entirely unjustified. That doesn’t mean that we shouldn’t care about reconciling macroeconomics with microeconomics; it just means that the validity of proposition in macroeconomics is not necessarily contingent on being derived from microeconomics. Reducing macroeconomics to microeconomics should be an analytical challenge, not a methodological imperative.

So the assumption, derived from Modigliani’s 1944 paper that “price stickiness” is what prevents an economic system from moving automatically to a new equilibrium after being subjected to some shock or disturbance, reflects either a misunderstanding or a semantic confusion. It is not price stickiness that prevents the system from moving toward equilibrium, it is the fact that individuals are engaging in transactions at disequilibrium prices. We simply do not know how to compare different sets of non-equilibrium prices to determine which set of non-equilibrium prices will move the economy further from or closer to equilibrium. Our experience and out intuition suggest that in some neighborhood of equilibrium, an economy can absorb moderate shocks without going into a cumulative contraction. But all we really know from theory is that any trading at any set of non-equilibrium prices can trigger an economic contraction, and once it starts to occur, a contraction may become cumulative.

It is also a mistake to assume that in a world of incomplete markets, the missing markets being markets for the delivery of goods and the provision of services in the future, any set of price adjustments, however large, could by themselves ensure that equilibrium is restored. With an incomplete set of markets, economic agents base their decisions not just on actual prices in the existing markets; they base their decisions on prices for future goods and services which can only be guessed at. And it is only when individual expectations of those future prices are mutually consistent that equilibrium obtains. With inconsistent expectations of future prices, the adjustments in current prices in the markets that exist for currently supplied goods and services that in some sense equate amounts demanded and supplied, lead to a (temporary) equilibrium that is not efficient, one that could be associated with high unemployment and unused capacity even though technically existing markets are clearing.

So that’s why I regard the term “sticky prices” and other similar terms as very unhelpful and misleading; they are a kind of mental crutch that economists are too ready to rely on as a substitute for thinking about what are the actual causes of economic breakdowns, crises, recessions, and depressions. Most of all, they represent an uncritical transfer of partial-equilibrium microeconomic thinking to a problem that requires a system-wide macroeconomic approach. That approach should not ignore microeconomic reasoning, but it has to transcend both partial-equilibrium supply-demand analysis and the mathematics of intertemporal optimization.


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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