Archive for the 'Say’s Law' Category

Welcome to Uneasy Money, aka the Hawtreyblog

UPDATE: I’m re-upping my introductory blog post, which I posted ten years ago toady. It’s been a great run for me, and I hope for many of you, whose interest and responses have motivated to keep it going. So thanks to all of you who have read and responded to my posts. I’m adding a few retrospective comments and making some slight revisions along the way. In addition to new posts, I will be re-upping some of my old posts that still seem to have relevance to the current state of our world.

What the world needs now, with apologies to the great Burt Bachrach and Hal David, is, well, another blog.  But inspired by the great Ralph Hawtrey and the near great Scott Sumner, I decided — just in time for Scott’s return to active blogging — to raise another voice on behalf of a monetary policy actively seeking to promote recovery from what I call the Little Depression, instead of the monetary policy we have now:  waiting for recovery to arrive on its own.  Just like the Great Depression, our Little Depression was caused mainly by overly tight money in an environment of over-indebtedness and financial fragility, and was then allowed to deepen and become entrenched by monetary authorities unwilling to commit themselves to a monetary expansion aimed at raising prices enough to make business expansion profitable.

That was the lesson of the Great Depression.  Unfortunately that lesson, for reasons too complicated to go into now, was never properly understood, because neither Keynesians nor Monetarists had a fully coherent understanding of what happened in the Great Depression.  Although Ralph Hawtrey — called by none other than Keynes “his grandparent in the paths of errancy,” and an early, but unacknowledged, progenitor of Chicago School Monetarism — had such an understanding,  Hawtrey’s contributions were overshadowed and largely ignored, because of often irrelevant and misguided polemics between Keynesians and Monetarists and Austrians.  One of my goals for this blog is to bring to light the many insights of this perhaps most underrated — though competition for that title is pretty stiff — economist of the twentieth century.  I have discussed Hawtrey’s contributions in my book on free banking and in a paper published years ago in Encounter and available here.  Patrick Deutscher has written a biography of Hawtrey.

What deters businesses from expanding output and employment in a depression is lack of demand; they fear that if they do expand, they won’t be able to sell the added output at prices high enough to cover their costs, winding up with redundant workers and having to engage in costly layoffs.  Thus, an expectation of low demand tends to be self-fulfilling.  But so is an expectation of rising prices, because the additional output and employment induced by expectations of rising prices will generate the demand that will validate the initial increase in output and employment, creating a virtuous cycle of rising income, expenditure, output, and employment.

The insight that “the inactivity of all is the cause of the inactivity of each” is hardly new.  It was not the discovery of Keynes or Keynesian economics; it is the 1922 formulation of Frederick Lavington, another great, but underrated, pre-Keynesian economist in the Cambridge tradition, who, in his modesty and self-effacement, would have been shocked and embarrassed to be credited with the slightest originality for that statement.  Indeed, Lavington’s dictum might even be understood as a restatement of Say’s Law, the bugbear of Keynes and object of his most withering scorn.  Keynesian economics skillfully repackaged the well-known and long-accepted idea that when an economy is operating with idle capacity and high unemployment, any increase in output tends to be self-reinforcing and cumulative, just as, on the way down, each reduction in output is self-reinforcing and cumulative.

But at least Keynesians get the point that, in a depression or deep recession, individual incentives may not be enough to induce a healthy expansion of output and employment. Aggregate demand can be too low for an expansion to get started on its own. Even though aggregate demand is nothing but the flip side of aggregate supply (as Say’s Law teaches), if resources are idle for whatever reason, perceived effective demand is deficient, diluting incentives to increase production so much that the potential output expansion does not materialize, because expected prices are too low for businesses to want to expand. But if businesses can be induced to expand output, more than likely, they will sell it, because (as Say’s Law teaches) supply usually does create its own demand.

[Comment after 10 years: In a comment, Rowe asked why I wrote that Say’s Law teaches that supply “usually” creates its own demand. At that time, I responded that I was just using “usually” as a weasel word. But I subsequently realized (and showed in a post last year) that the standard proofs of both Walras’s Law and Say’s Law are defective for economies with incomplete forward and state-contingent markets. We actually know less than we once thought we did!] 

Keynesians mistakenly denied that, by creating price-level expectations consistent with full employment, monetary policy could induce an expansion of output even in a depression. But at least they understood that the private economy can reach an impasse with price-level expectations too low to sustain full employment. Fiscal policy may play a role in remedying a mismatch between expectations and full employment, but fiscal policy can only be as effective as monetary policy allows it to be. Unfortunately, since the downturn of December 2007, monetary policy, except possibly during QE1 and QE2, has consistently erred on the side of uneasiness.

With some unfortunate exceptions, however, few Keynesians have actually argued against monetary easing. Rather, with some honorable exceptions, it has been conservatives who, by condemning a monetary policy designed to provide incentives conducive to business expansion, have helped to hobble a recovery led by the private sector rather than the government which  they profess to want. It is not my habit to attribute ill motives or bad faith to people whom I disagree with. One of the finest compliments ever paid to F. A. Hayek was by Joseph Schumpeter in his review of The Road to Serfdom who chided Hayek for “politeness to a fault in hardly ever attributing to his opponents anything but intellectual error.” But it is a challenge to come up with a plausible explanation for right-wing opposition to monetary easing.

[Comment after 10 years: By 2011 when this post was written, right-wing bad faith had already become too obvious to ignore, but who could then have imagined where the willingness to resort to bad faith arguments without the slightest trace of compunction would lead them and lead us.] 

In condemning monetary easing, right-wing opponents claim to be following the good old conservative tradition of supporting sound money and resisting the inflationary proclivities of Democrats and liberals. But how can claims of principled opposition to inflation be taken seriously when inflation, by every measure, is at its lowest ebb since the 1950s and early 1960s? With prices today barely higher than they were three years ago before the crash, scare talk about currency debasement and future hyperinflation reminds me of Ralph Hawtrey’s famous remark that warnings that leaving the gold standard during the Great Depression would cause runaway inflation were like crying “fire, fire” in Noah’s flood.

The groundlessness of right-wing opposition to monetary easing becomes even plainer when one recalls the attacks on Paul Volcker during the first Reagan administration. In that episode President Reagan and Volcker, previously appointed by Jimmy Carter to replace the feckless G. William Miller as Fed Chairman, agreed to make bringing double-digit inflation under control their top priority, whatever the short-term economic and political costs. Reagan, indeed, courageously endured a sharp decline in popularity before the first signs of a recovery became visible late in the summer of 1982, too late to save Reagan and the Republicans from a drubbing in the mid-term elections, despite the drop in inflation to 3-4 percent. By early 1983, with recovery was in full swing, the Fed, having abandoned its earlier attempt to impose strict Monetarist controls on monetary expansion, allowed the monetary aggregates to grow at unusually rapid rates.

However, in 1984 (a Presidential election year) after several consecutive quarters of GDP growth at annual rates above 7 percent, the Fed, fearing a resurgence of inflation, began limiting the rate of growth in the monetary aggregates. Reagan’s secretary of the Treasury, Donald Regan, as well as a variety of outside Administration supporters like Arthur Laffer, Larry Kudlow, and the editorial page of the Wall Street Journal, began to complain bitterly that the Fed, in its preoccupation with fighting inflation, was deliberately sabotaging the recovery. The argument against the Fed’s tightening of monetary policy in 1984 was not without merit. But regardless of the wisdom of the Fed tightening in 1984 (when inflation was significantly higher than it is now), holding up the 1983-84 Reagan recovery as the model for us to follow now, while excoriating Obama and Bernanke for driving inflation all the way up to 1 percent, supposedly leading to currency debauchment and hyperinflation, is just a bit rich. What, I wonder, would Hawtrey have said about that?

In my next posting I will look a little more closely at some recent comparisons between the current non-recovery and recoveries from previous recessions, especially that of 1983-84.

A Primer on Say’s Law and Walras’s Law

Say’s Law, often paraphrased as “supply creates its own demand,” is one of oldest “laws” in economics. It is also one of the least understood and most contentious propositions in economics. I am now in the process of revising my current draft of my paper “Say’s Law and the Classical Theory of Depressions,” which surveys and clarifies various interpretations, disputes and misunderstandings about Say’s Law. I thought that a brief update of my section discussing the relationship between Say’s Law and Walras’s Law might make for a useful blogpost. Not only does it discuss the meaning of Say’s Law and its relationship to Walras’s Law, it expands the narrow understanding of Say’s Law and corrects the mistaken view that Say’s Law does not hold in a monetary economy, because, given a demand to hold a pure medium of exchange, real goods may be supplied only to accumulate cash not to obtain real goods and services. IOW, supply may be a demand for cash not for goods. Under this interpretation, Say’s Law is valid only when the economy is in a macro or monetary equilibrium with no excess demand for money.

Here’s my discussion of that logically incorrect belief. (Let me add as a qualification that not only Say’s Law, but Walras’s Law, as I explained elsewhere in my paper, is not valid when there is not a complete set of forward and contingent markets. That’s because to prove Walras’s Law all agents must be optimizing on the same set of prices, whether actual observed prices or expected, but currently unobserved, prices. See also an earlier post about this paper in which I included the relevant excerpt from the paper.)

The argument that a demand to hold cash invalidates Say’s Law, because output may be produced for the purpose of accumulating cash rather than to buy other goods and services is an argument that had been made by nineteenth-century critics of Say’s Law. The argument did not go without response, but the nature and import of the response was not well, or widely, understood, and the criticism was widely credited. Thus, in his early writings on business-cycle theory, F. A. Hayek, making no claim to originality, maintained, matter of factly, that money involves a disconnect between aggregate supply and aggregate demand, describing money as a “loose joint” in the theory of general equilibrium, creating the central theoretical problem to be addressed by business-cycle theory. So, even Hayek in 1927 did not accept the validity of Say’s Law

Oskar Lange (“Say’s Law a Restatement and Criticism”) subsequently formalized the problem, introducing his distinction between Say’s Law and Walras’s Law. Lange defined Walras’s Law as the proposition that the sum of excess demands, corresponding to any price vector announced by a Walrasian auctioneer, must identically equal zero.[1] In a barter model, individual optimization, subject to the budget constraint corresponding to a given price vector, implies that the value of the planned purchases and planned sales by each agent must be exactly equal; if the value of the excess demands of each individual agent is zero the sum of the values of the excess demands of all individuals must also be zero. In a barter model, Walras’s Law and Say’s Law are equivalent: demand is always sufficient to absorb supply.

But in a model in which agents hold cash, which they use when transacting, they may supply real goods in order to add to their cash holdings. Because individual agents may seek to change their cash holdings, Lange argued that the equivalence between Walras’s Law and Say’s Law in a barter model does not carry over to a model in which agents hold money. Say’s Law cannot hold in such an economy unless excess demands in the markets for real goods sum to zero. But if agents all wish to add to their holdings of cash, their excess demand for cash will be offset by an excess supply of goods, which is precisely what Say’s Law denies.

It is only when an equilibrium price vector is found at which the excess demand in each market is zero that Say’s Law is satisfied. Say’s Law, according to Lange, is a property of a general equilibrium, not a necessary property of rational economic conduct, as Say and his contemporaries and followers had argued. When our model is extended from a barter to a monetary setting, Say’s Law must be restated in the generalized form of Walras’s Law. But, unlike Say’s Law, Walras’s Law does not exclude the possibility of an aggregate excess supply of all goods. Aggregate demand can be deficient, and it can result in involuntary unemployment.

At bottom, this critique of Say’s Law depends on the assumption that the quantity of money is exogenously fixed, so that individuals can increase or decrease their holdings of money only by spending either less or more than their incomes. However, as noted above, if there is a market mechanism that allows an increased demand for cash balances to elicit an increased quantity of cash balances, so that the public need not reduce expenditures to finance additions to their holdings of cash, Lange’s critique may not invalidate Say’s Law.

A competitive monetary system based on convertibility into gold or some other asset[2] has precisely this property. In particular, with money privately supplied by a set of traders (let’s call them banks), money is created when a bank accepts a money-backing asset (IOU) supplied by a customer in exchange for issuing its liability (a banknote or a deposit), which is widely acceptable as a medium of exchange. As first pointed out by Thompson (1974), Lange’s analytical oversight was to assume that in a Walrasian model with n real goods and money, there are only (n+1) goods or assets. In fact, there are really (n+2) goods or assets; there are n real goods and two monetary assets (i.e., the money issued by the bank and the money-backing asset accepted by the bank in exchange for the money that it issues). Thus, an excess demand for money need not, as Lange assumed, be associated with, or offset by, an excess supply of real commodities; it may be offset by a supply of money-backing assets supplied by those seeking to increase their cash holdings.

Properly specifying the monetary model relevant to macroeconomic analysis eliminates a misconception that afflicted monetary and macroeconomic theory for a very long time, and provides a limited rehabilitation of Say’s Law. But that rehabilitation doesn’t mean that all would be well if we got rid of central banks, abandoned all countercyclical policies and let private banks operate without restrictions. None of those difficult and complicated questions can be answered by invoking or rejecting Say’s Law.

[1] Excess supplies are recorded as negative excess demands.

[2] The classical economists generally regarded gold or silver as the appropriate underlying asset into which privately issued monies would be convertible, but the possibility of a fiat standard was not rejected on analytical principle.

Say’s (and Walras’s) Law Revisited

Update (6/18/2019): The current draft of my paper is now available on SSRN. Here is a link.

The annual meeting of the History of Economics Society is coming up in two weeks. It will be held at Columbia University at New York, and I will be presenting an unpublished paper of mine “Say’s Law and the Classical Theory of Depressions.” I began writing this paper about 20 years ago, but never finished it. My thinking about Say’s Law goes back to my first paper on classical monetary theory, and I have previously written blog-posts about Say’s Law (here and here). And more recently I realized that in a temporary-equilibrium framework, both Say’s Law and Walras’s Law, however understood, may be violated.

Here’s the abstract from my paper:

Say’s Law occupies a prominent, but equivocal, position in the history of economics, having been the object of repeated controversies about its meaning and significance since it was first propounded early in the nineteenth century. It has been variously defined, and arguments about its meaning and validity have not reached consensus about what was being attacked or defended. This paper proposes a unifying interpretation of Say’s Law based on the idea that the monetary sector of an economy with a competitively supplied money involves at least two distinct markets not just one. Thus, contrary to the Lange-Patinkin interpretation of Say’s Law, an excess supply or demand for money does not necessarily imply an excess supply or demand for goods in a Walrasian GE model. Beyond modifying the standard interpretation of the inconsistency between Say’s Law and a monetary economy, the paper challenges another standard interpretation of Say’s Law as being empirically refuted by the existence of lapses from full employment and economic depressions. Under the alternative interpretation, originally suggested by Clower and Leijonhufvud and by Hutt, Say’s Law provides a theory whereby disequilibrium in one market, causing the amount actually supplied to fall short of what had been planned to be supplied, reduces demand in other markets, initiating a cumulative process of shrinking demand and supply. This cumulative process of contracting supply is analogous to the Keynesian multiplier whereby a reduction in demand initiates a cumulative process of declining demand. Finally, it is shown that in a temporary-equilibrium context, Walras’s Law (and a fortiori Say’ Law) may be violated.

Here is the Introduction of my paper.

I. Introduction

Say’s Law occupies a prominent, but uncertain, position in the history of economics, having been the object of repeated controversies since the early nineteenth century. Despite a formidable secondary literature, the recurring controversies still demand a clear resolution. Say’s Law has been variously defined, and arguments about its meaning and validity have failed to achieve any clear consensus about just what is being defended or attacked. So, I propose in this paper to reconsider Say’s Law in a way that is faithful in spirit to how it was understood by its principal architects, J. B. Say, James Mill, and David Ricardo as well as their contemporary critics, and to provide a conceptual framework within which to assess the views of subsequent commentators.

In doing so, I hope to dispel perhaps the oldest and certainly the most enduring misunderstanding about Say’s Law: that it somehow was meant to assert that depressions cannot occur, or that they are necessarily self-correcting if market forces are allowed to operate freely. As I have tried to suggest with the title of this paper, Say’s Law was actually an element of Classical insights into the causes of depressions. Indeed, a version of the same idea expressed by Say’s Law implicitly underlies those modern explanations of depressions that emphasize coordination failures, though Say’s Law actually conveys an additional insight missing from most modern explanations.

The conception of Say’s Law articulated in this paper bears a strong resemblance to what Clower (1965, 1967) and Leijonhufvud (1968, 1981) called Say’s Principle. However, their artificial distinction between Say’s Law and Say’s Principle suggests a narrower conception and application of Say’s principle than, I believe, is warranted.  Moreover, their apparent endorsement of the idea that the validity of Say’s Law somehow depends in a critical way on the absence of money implied a straightforward misinterpretation of Say’s Law earlier propounded by, among other, Hayek, Lange and Patinkin in which only what became known as Walras’s Law and not Say’s Law is a logically necessary property of a general-equilibrium system. Finally, it is appropriate to note at the outset that, in most respects, the conception of Say’s Law for which I shall be arguing was anticipated in a quirky, but unjustly neglected, work by Hutt (1975) and by the important, and similarly neglected, work of Earl Thompson (1974).

In the next section, I offer a restatement of the Classical conception of Say’s Law. That conception was indeed based on the insight that, in the now familiar formulation, supply creates its own demand. But to grasp how this insight was originally understood, one must first understand the problem for which Say’s Law was proposed as a solution. The problem concerns the relationship between a depression and a general glut of all goods, but it has two aspects. First, is a depression in some sense caused by a general glut of all goods? Second, is a general glut of all goods logically conceivable in a market economy? In section three, I shall consider the Classical objections to Say’s Law and the responses offered by the Classical originators of the doctrine in reply to those objections. In section four, I discuss the modern objections offered to Say’s Law, their relation to the earlier objections, and the validity of the modern objections to the doctrine. In section five, I re-examine the Classical doctrine, relating it explicitly to a theory of depressions characterized by “inadequate aggregate demand.” I also elaborate on the subtle, but important, differences between my understanding of Say’s Law and what Clower and Leijonhufvud have called Say’s Principle. In section six, I show that when considered in the context of a temporary-equilibrium model in there is an incomplete set of forward and state-contingent markets, not even Walras’s Law, let alone Say’s Law, is logically necessary property of the model. An understanding of the conditions in which neither Walras’s Law nor Say’s Law is satisfied provides an important insight into financial crises and the systemic coordination failures that are characteristic of the deep depression to which they lead.

And here are the last two sections of the paper.

VI. Say’s Law Violated

            I have just argued that Clower, Leijonhufvud and Hutt explained in detail how the insight provided by Say’s Law into the mechanism whereby disturbances causing disequilibrium in one market or sector can be propagated and amplified into broader and deeper economy-wide disturbances and disequilibria. I now want to argue that by relaxing the strict Walrasian framework in which since Lange (1942) articulated Walras’s Law and Say’s Law, it is possible to show conditions under which neither Walras’s Law nor Say’s Law is satisfied.

            I relax the Walrasian framework by assuming that there is not a complete set of forward and state-contingent markets in which future transactions can be undertaken in the present. Because there a complete set of markets in which future prices are determined and visible to everyone, economic agents must formulate their intertemporal plans for production and consumption relying not only on observed current prices, but also on their expectations of currently unobservable future prices. As already noted, the standard proof of Walras’s Law and a fortiori of Say’s Law (or Identity) are premised on the assumption that all agents make their decisions about purchases and sales on their common knowledge of all prices.

            Thus, in the temporary-equilibrium framework, economic agents make their production and consumption decisions not on the basis of their common knowledge of future market prices common, but on their own conjectural expectations of those prices, expectations that may, or may not, be correct, and may, or may not, be aligned with the expectations of other agents. Unless the agents’ expectations of future prices are aligned, the expectations of some, or all, agents must be disappointed, and the plans to buy and sell formulated based on those expectations will have to be revised, or abandoned, once agents realize that their expectations were incorrect.

            Consider a simple two-person, two-good, two-period model in which agents make plans based on current prices observed in period 1 and their expectations of what prices will be in period 2. Given price expectations for period 2, period-1 prices are determined in a tatonnement process, so that no trading occurs until a temporary- equilibrium price vector for period 1 is found. Assume, further, that price expectations for period 2 do not change in the course of the tatonnement. Once a period-1 equilibrium price vector is found, the two budget constraints subject to which the agents make their optimal decisions, need not have the same values for expected prices in period 2, because it is not assumed that the period-2 price expectations of the two agents are aligned. Because the proof of Walras’s Law depends on agents basing their decisions to buy and sell each commodity on prices for each commodity in each period that are common to both agents, Walras’s Law cannot be proved unless the period-2 price expectations of both agents are aligned.

            The implication of the potential violation of Walras’s Law is that when actual prices turn out to be different from what they were expected to be, economic agents who previously assumed obligations that are about to come due may be unable to discharge those obligations. In standard general-equilibrium models, the tatonnement process assures that no trading takes place unless equilibrium prices have been identified. But in a temporary-equilibrium model, when decisions to purchase and sell are based not on equilibrium prices, but on actual prices that may not have been expected, the discharge of commitments is not certain.

            Of course, if Walras’s Law cannot be proved, neither can Say’s Law. Supply cannot create demand when the insolvency of economic agents obstructs mutually advantageous transactions between agents when some agents have negative net worth. The negative net worth of some agents can be transmitted to other agents holding obligations undertaken by agents whose net worth has become negative.

            Moreover, because the private supply of a medium of exchange by banks depends on the value of money-backing assets held by banks, the monetary system may cease to function in an economy in which the net worth of agents whose obligations are held banks becomes negative. Thus, the argument made in section IV.A for the validity of Say’s Law in the Identity sense breaks down once a sufficient number of agents no longer have positive net worth.

VII.      Conclusion

            My aim in this paper has been to explain and clarify a number of the different ways in which Say’s Law has been understood and misunderstood. A fair reading of the primary and secondary literature allows one to understand that many of the criticisms of Say’s Law have been not properly understood the argument that Say’s Law was either intended or could be reasonably interpreted to have said. Indeed, Say’s Law, properly understood, can actually help one understand the cumulative process of economic contraction whose existence supposedly proved its invalidity. However, I have also been able to show that there are plausible conditions in which a sufficiently serious financial breakdown, associated with financial crises in which substantial losses of net worth lead to widespread and contagious insolvency, when even Walras’s Law, and a fortiori Say’s Law, no longer hold. Understanding how Say’s Law may be violated may thus help in understanding the dynamics of financial crises and the cumulative systemic coordination failures of deep depressions.

I will soon be posting the paper on SSRN. When it’s posted I will post a link to an update to this post.

 

Hayek and Intertemporal Equilibrium

I am starting to write a paper on Hayek and intertemporal equilibrium, and as I write it over the next couple of weeks, I am going to post sections of it on this blog. Comments from readers will be even more welcome than usual, and I will do my utmost to reply to comments, a goal that, I am sorry to say, I have not been living up to in my recent posts.

The idea of equilibrium is an essential concept in economics. It is an essential concept in other sciences as well, its meaning in economics is not the same as in other disciplines. The concept having originally been borrowed from physics, the meaning originally attached to it by economists corresponded to the notion of a system at rest, and it took a long time for economists to see that viewing an economy as a system at rest was not the only, or even the most useful, way of applying the equilibrium concept to economic phenomena.

What would it mean for an economic system to be at rest? The obvious answer was to say that prices and quantities would not change. If supply equals demand in every market, and if there no exogenous change introduced into the system, e.g., in population, technology, tastes, etc., it would seem that would be no reason for the prices paid and quantities produced to change in that system. But that view of an economic system was a very restrictive one, because such a large share of economic activity – savings and investment — is predicated on the assumption and expectation of change.

The model of a stationary economy at rest in which all economic activity simply repeats what has already happened before did not seem very satisfying or informative, but that was the view of equilibrium that originally took hold in economics. The idea of a stationary timeless equilibrium can be traced back to the classical economists, especially Ricardo and Mill who wrote about the long-run tendency of an economic system toward a stationary state. But it was the introduction by Jevons, Menger, Walras and their followers of the idea of optimizing decisions by rational consumers and producers that provided the key insight for a more robust and fruitful version of the equilibrium concept.

If each economic agent (household or business firm) is viewed as making optimal choices based on some scale of preferences subject to limitations or constraints imposed by their capacities, endowments, technology and the legal system, then the equilibrium of an economy must describe a state in which each agent, given his own subjective ranking of the feasible alternatives, is making a optimal decision, and those optimal decisions are consistent with those of all other agents. The optimal decisions of each agent must simultaneously be optimal from the point of view of that agent while also being consistent, or compatible, with the optimal decisions of every other agent. In other words, the decisions of all buyers of how much to purchase must be consistent with the decisions of all sellers of how much to sell.

The idea of an equilibrium as a set of independently conceived, mutually consistent optimal plans was latent in the earlier notions of equilibrium, but it could not be articulated until a concept of optimality had been defined. That concept was utility maximization and it was further extended to include the ideas of cost minimization and profit maximization. Once the idea of an optimal plan was worked out, the necessary conditions for the mutual consistency of optimal plans could be articulated as the necessary conditions for a general economic equilibrium. Once equilibrium was defined as the consistency of optimal plans, the path was clear to define an intertemporal equilibrium as the consistency of optimal plans extending over time. Because current goods and services and otherwise identical goods and services in the future could be treated as economically distinct goods and services, defining the conditions for an intertemporal equilibrium was formally almost equivalent to defining the conditions for a static, stationary equilibrium. Just as the conditions for a static equilibrium could be stated in terms of equalities between marginal rates of substitution of goods in consumption and in production to their corresponding price ratios, an intertemporal equilibrium could be stated in terms of equalities between the marginal rates of intertemporal substitution in consumption and in production and their corresponding intertemporal price ratios.

The only formal adjustment required in the necessary conditions for static equilibrium to be extended to intertemporal equilibrium was to recognize that, inasmuch as future prices (typically) are unobservable, and hence unknown to economic agents, the intertemporal price ratios cannot be ratios between actual current prices and actual future prices, but, instead, ratios between current prices and expected future prices. From this it followed that for optimal plans to be mutually consistent, all economic agents must have the same expectations of the future prices in terms of which their plans were optimized.

The concept of an intertemporal equilibrium was first presented in English by F. A. Hayek in his 1937 article “Economics and Knowledge.” But it was through J. R. Hicks’s Value and Capital published two years later in 1939 that the concept became more widely known and understood. In explaining and applying the concept of intertemporal equilibrium and introducing the derivative concept of a temporary equilibrium in which current markets clear, but individual expectations of future prices are not the same, Hicks did not claim originality, but instead of crediting Hayek for the concept, or even mentioning Hayek’s 1937 paper, Hicks credited the Swedish economist Erik Lindahl, who had published articles in the early 1930s in which he had articulated the concept. But although Lindahl had published his important work on intertemporal equilibrium before Hayek’s 1937 article, Hayek had already explained the concept in a 1928 article “Das intertemporale Gleichgewichtasystem der Priese und die Bewegungen des ‘Geltwertes.'” (English translation: “Intertemporal price equilibrium and movements in the value of money.“)

Having been a junior colleague of Hayek’s in the early 1930s when Hayek arrived at the London School of Economics, and having come very much under Hayek’s influence for a few years before moving in a different theoretical direction in the mid-1930s, Hicks was certainly aware of Hayek’s work on intertemporal equilibrium, so it has long been a puzzle to me why Hicks did not credit Hayek along with Lindahl for having developed the concept of intertemporal equilibrium. It might be worth pursuing that question, but I mention it now only as an aside, in the hope that someone else might find it interesting and worthwhile to try to find a solution to that puzzle. As a further aside, I will mention that Murray Milgate in a 1979 article “On the Origin of the Notion of ‘Intertemporal Equilibrium’” has previously tried to redress the failure to credit Hayek’s role in introducing the concept of intertemporal equilibrium into economic theory.

What I am going to discuss in here and in future posts are three distinct ways in which the concept of intertemporal equilibrium has been developed since Hayek’s early work – his 1928 and 1937 articles but also his 1941 discussion of intertemporal equilibrium in The Pure Theory of Capital. Of course, the best known development of the concept of intertemporal equilibrium is the Arrow-Debreu-McKenzie (ADM) general-equilibrium model. But although it can be thought of as a model of intertemporal equilibrium, the ADM model is set up in such a way that all economic decisions are taken before the clock even starts ticking; the transactions that are executed once the clock does start simply follow a pre-determined script. In the ADM model, the passage of time is a triviality, merely a way of recording the sequential order of the predetermined production and consumption activities. This feat is accomplished by assuming that all agents are present at time zero with their property endowments in hand and capable of transacting – but conditional on the determination of an equilibrium price vector that allows all optimal plans to be simultaneously executed over the entire duration of the model — in a complete set of markets (including state-contingent markets covering the entire range of contingent events that will unfold in the course of time whose outcomes could affect the wealth or well-being of any agent with the probabilities associated with every contingent event known in advance).

Just as identical goods in different physical locations or different time periods can be distinguished as different commodities that cn be purchased at different prices for delivery at specific times and places, identical goods can be distinguished under different states of the world (ice cream on July 4, 2017 in Washington DC at 2pm only if the temperature is greater than 90 degrees). Given the complete set of state-contingent markets and the known probabilities of the contingent events, an equilibrium price vector for the complete set of markets would give rise to optimal trades reallocating the risks associated with future contingent events and to an optimal allocation of resources over time. Although the ADM model is an intertemporal model only in a limited sense, it does provide an ideal benchmark describing the characteristics of a set of mutually consistent optimal plans.

The seminal work of Roy Radner in relaxing some of the extreme assumptions of the ADM model puts Hayek’s contribution to the understanding of the necessary conditions for an intertemporal equilibrium into proper perspective. At an informal level, Hayek was addressing the same kinds of problems that Radner analyzed with far more powerful analytical tools than were available to Hayek. But the were both concerned with a common problem: under what conditions could an economy with an incomplete set of markets be said to be in a state of intertemporal equilibrium? In an economy lacking the full set of forward and state contingent markets describing the ADM model, intertemporal equilibrium cannot predetermined before trading even begins, but must, if such an equilibrium obtains, unfold through the passage of time. Outcomes might be expected, but they would not be predetermined in advance. Echoing Hayek, though to my knowledge he does not refer to Hayek in his work, Radner describes his intertemporal equilibrium under uncertainty as an equilibrium of plans, prices, and price expectations. Even if it exists, the Radner equilibrium is not the same as the ADM equilibrium, because without a full set of markets, agents can’t fully hedge against, or insure, all the risks to which they are exposed. The distinction between ex ante and ex post is not eliminated in the Radner equilibrium, though it is eliminated in the ADM equilibrium.

Additionally, because all trades in the ADM model have been executed before “time” begins, it seems impossible to rationalize holding any asset whose only use is to serve as a medium of exchange. In his early writings on business cycles, e.g., Monetary Theory and the Trade Cycle, Hayek questioned whether it would be possible to rationalize the holding of money in the context of a model of full equilibrium, suggesting that monetary exchange, by severing the link between aggregate supply and aggregate demand characteristic of a barter economy as described by Say’s Law, was the source of systematic deviations from the intertemporal equilibrium corresponding to the solution of a system of Walrasian equations. Hayek suggested that progress in analyzing economic fluctuations would be possible only if the Walrasian equilibrium method could be somehow be extended to accommodate the existence of money, uncertainty, and other characteristics of the real world while maintaining the analytical discipline imposed by the equilibrium method and the optimization principle. It proved to be a task requiring resources that were beyond those at Hayek’s, or probably anyone else’s, disposal at the time. But it would be wrong to fault Hayek for having had to insight to perceive and frame a problem that was beyond his capacity to solve. What he may be criticized for is mistakenly believing that he he had in fact grasped the general outlines of a solution when in fact he had only perceived some aspects of the solution and offering seriously inappropriate policy recommendations based on that seriously incomplete understanding.

In Value and Capital, Hicks also expressed doubts whether it would be possible to analyze the economic fluctuations characterizing the business cycle using a model of pure intertemporal equilibrium. He proposed an alternative approach for analyzing fluctuations which he called the method of temporary equilibrium. The essence of the temporary-equilibrium method is to analyze the behavior of an economy under the assumption that all markets for current delivery clear (in some not entirely clear sense of the term “clear”) while understanding that demand and supply in current markets depend not only on current prices but also upon expected future prices, and that the failure of current prices to equal what they had been expected to be is a potential cause for the plans that economic agents are trying to execute to be modified and possibly abandoned. In the Pure Theory of Capital, Hayek discussed Hicks’s temporary-equilibrium method a possible method of achieving the modification in the Walrasian method that he himself had proposed in Monetary Theory and the Trade Cycle. But after a brief critical discussion of the method, he dismissed it for reasons that remain obscure. Hayek’s rejection of the temporary-equilibrium method seems in retrospect to have been one of Hayek’s worst theoretical — or perhaps, meta-theoretical — blunders.

Decades later, C. J. Bliss developed the concept of temporary equilibrium to show that temporary equilibrium method can rationalize both holding an asset purely for its services as a medium of exchange and the existence of financial intermediaries (private banks) that supply financial assets held exclusively to serve as a medium of exchange. In such a temporary-equilibrium model with financial intermediaries, it seems possible to model not only the existence of private suppliers of a medium of exchange, but also the conditions – in a very general sense — under which the system of financial intermediaries breaks down. The key variable of course is vectors of expected prices subject to which the plans of individual households, business firms, and financial intermediaries are optimized. The critical point that emerges from Bliss’s analysis is that there are sets of expected prices, which if held by agents, are inconsistent with the existence of even a temporary equilibrium. Thus price flexibility in current market cannot, in principle, result in even a temporary equilibrium, because there is no price vector of current price in markets for present delivery that solves the temporary-equilibrium system. Even perfect price flexibility doesn’t lead to equilibrium if the equilibrium does not exist. And the equilibrium cannot exist if price expectations are in some sense “too far out of whack.”

Expected prices are thus, necessarily, equilibrating variables. But there is no economic mechanism that tends to cause the adjustment of expected prices so that they are consistent with the existence of even a temporary equilibrium, much less a full equilibrium.

Unfortunately, modern macroeconomics continues to neglect the temporary-equilibrium method; instead macroeconomists have for the most part insisted on the adoption of the rational-expectations hypothesis, a hypothesis that elevates question-begging to the status of a fundamental axiom of rationality. The crucial error in the rational-expectations hypothesis was to misunderstand the role of the comparative-statics method developed by Samuelson in The Foundations of Economic Analysis. The role of the comparative-statics method is to isolate the pure theoretical effect of a parameter change under a ceteris-paribus assumption. Such an effect could be derived only by comparing two equilibria under the assumption of a locally unique and stable equilibrium before and after the parameter change. But the method of comparative statics is completely inappropriate to most macroeconomic problems which are precisely concerned with the failure of the economy to achieve, or even to approximate, the unique and stable equilibrium state posited by the comparative-statics method.

Moreover, the original empirical application of the rational-expectations hypothesis by Muth was in the context of the behavior of a single market in which the market was dominated by well-informed specialists who could be presumed to have well-founded expectations of future prices conditional on a relatively stable economic environment. Under conditions of macroeconomic instability, there is good reason to doubt that the accumulated knowledge and experience of market participants would enable agents to form accurate expectations of the future course of prices even in those markets about which they expert knowledge. Insofar as the rational expectations hypothesis has any claim to empirical relevance it is only in the context of stable market situations that can be assumed to be already operating in the neighborhood of an equilibrium. For the kinds of problems that macroeconomists are really trying to answer that assumption is neither relevant nor appropriate.

Krugman’s Second Best

A couple of days ago Paul Krugman discussed “Second-best Macroeconomics” on his blog. I have no real quarrel with anything he said, but I would like to amplify his discussion of what is sometimes called the problem of second-best, because I think the problem of second best has some really important implications for macroeconomics beyond the limited application of the problem that Krugman addressed. The basic idea underlying the problem of second best is not that complicated, but it has many applications, and what made the 1956 paper (“The General Theory of Second Best”) by R. G. Lipsey and Kelvin Lancaster a classic was that it showed how a number of seemingly disparate problems were really all applications of a single unifying principle. Here’s how Krugman frames his application of the second-best problem.

[T]he whole western world has spent years suffering from a severe shortfall of aggregate demand; in Europe a severe misalignment of national costs and prices has been overlaid on this aggregate problem. These aren’t hard problems to diagnose, and simple macroeconomic models — which have worked very well, although nobody believes it — tell us how to solve them. Conventional monetary policy is unavailable thanks to the zero lower bound, but fiscal policy is still on tap, as is the possibility of raising the inflation target. As for misaligned costs, that’s where exchange rate adjustments come in. So no worries: just hit the big macroeconomic That Was Easy button, and soon the troubles will be over.

Except that all the natural answers to our problems have been ruled out politically. Austerians not only block the use of fiscal policy, they drive it in the wrong direction; a rise in the inflation target is impossible given both central-banker prejudices and the power of the goldbug right. Exchange rate adjustment is blocked by the disappearance of European national currencies, plus extreme fear over technical difficulties in reintroducing them.

As a result, we’re stuck with highly problematic second-best policies like quantitative easing and internal devaluation.

I might quibble with Krugman about the quality of the available macroeconomic models, by which I am less impressed than he, but that’s really beside the point of this post, so I won’t even go there. But I can’t let the comment about the inflation target pass without observing that it’s not just “central-banker prejudices” and the “goldbug right” that are to blame for the failure to raise the inflation target; for reasons that I don’t claim to understand myself, the political consensus in both Europe and the US in favor of perpetually low or zero inflation has been supported with scarcely any less fervor by the left than the right. It’s only some eccentric economists – from diverse positions on the political spectrum – that have been making the case for inflation as a recovery strategy. So the political failure has been uniform across the political spectrum.

OK, having registered my factual disagreement with Krugman about the source of our anti-inflationary intransigence, I can now get to the main point. Here’s Krugman:

“[S]econd best” is an economic term of art. It comes from a classic 1956 paper by Lipsey and Lancaster, which showed that policies which might seem to distort markets may nonetheless help the economy if markets are already distorted by other factors. For example, suppose that a developing country’s poorly functioning capital markets are failing to channel savings into manufacturing, even though it’s a highly profitable sector. Then tariffs that protect manufacturing from foreign competition, raise profits, and therefore make more investment possible can improve economic welfare.

The problems with second best as a policy rationale are familiar. For one thing, it’s always better to address existing distortions directly, if you can — second best policies generally have undesirable side effects (e.g., protecting manufacturing from foreign competition discourages consumption of industrial goods, may reduce effective domestic competition, and so on). . . .

But here we are, with anything resembling first-best macroeconomic policy ruled out by political prejudice, and the distortions we’re trying to correct are huge — one global depression can ruin your whole day. So we have quantitative easing, which is of uncertain effectiveness, probably distorts financial markets at least a bit, and gets trashed all the time by people stressing its real or presumed faults; someone like me is then put in the position of having to defend a policy I would never have chosen if there seemed to be a viable alternative.

In a deep sense, I think the same thing is involved in trying to come up with less terrible policies in the euro area. The deal that Greece and its creditors should have reached — large-scale debt relief, primary surpluses kept small and not ramped up over time — is a far cry from what Greece should and probably would have done if it still had the drachma: big devaluation now. The only way to defend the kind of thing that was actually on the table was as the least-worst option given that the right response was ruled out.

That’s one example of a second-best problem, but it’s only one of a variety of problems, and not, it seems to me, the most macroeconomically interesting. So here’s the second-best problem that I want to discuss: given one distortion (i.e., a departure from one of the conditions for Pareto-optimality), reaching a second-best sub-optimum requires violating other – likely all the other – conditions for reaching the first-best (Pareto) optimum. The strategy for getting to the second-best suboptimum cannot be to achieve as many of the conditions for reaching the first-best optimum as possible; the conditions for reaching the second-best optimum are in general totally different from the conditions for reaching the first-best optimum.

So what’s the deeper macroeconomic significance of the second-best principle?

I would put it this way. Suppose there’s a pre-existing macroeconomic equilibrium, all necessary optimality conditions between marginal rates of substitution in production and consumption and relative prices being satisfied. Let the initial equilibrium be subjected to a macoreconomic disturbance. The disturbance will immediately affect a range — possibly all — of the individual markets, and all optimality conditions will change, so that no market will be unaffected when a new optimum is realized. But while optimality for the system as a whole requires that prices adjust in such a way that the optimality conditions are satisfied in all markets simultaneously, each price adjustment that actually occurs is a response to the conditions in a single market – the relationship between amounts demanded and supplied at the existing price. Each price adjustment being a response to a supply-demand imbalance in an individual market, there is no theory to explain how a process of price adjustment in real time will ever restore an equilibrium in which all optimality conditions are simultaneously satisfied.

Invoking a general Smithian invisible-hand theorem won’t work, because, in this context, the invisible-hand theorem tells us only that if an equilibrium price vector were reached, the system would be in an optimal state of rest with no tendency to change. The invisible-hand theorem provides no account of how the equilibrium price vector is discovered by any price-adjustment process in real time. (And even tatonnement, a non-real-time process, is not guaranteed to work as shown by the Sonnenschein-Mantel-Debreu Theorem). With price adjustment in each market entirely governed by the demand-supply imbalance in that market, market prices determined in individual markets need not ensure that all markets clear simultaneously or satisfy the optimality conditions.

Now it’s true that we have a simple theory of price adjustment for single markets: prices rise if there’s an excess demand and fall if there’s an excess supply. If demand and supply curves have normal slopes, the simple price adjustment rule moves the price toward equilibrium. But that partial-equilibriuim story is contingent on the implicit assumption that all other markets are in equilibrium. When all markets are in disequilibrium, moving toward equilibrium in one market will have repercussions on other markets, and the simple story of how price adjustment in response to a disequilibrium restores equilibrium breaks down, because market conditions in every market depend on market conditions in every other market. So unless all markets arrive at equilibrium simultaneously, there’s no guarantee that equilibrium will obtain in any of the markets. Disequilibrium in any market can mean disequilibrium in every market. And if a single market is out of kilter, the second-best, suboptimal solution for the system is totally different from the first-best solution for all markets.

In the standard microeconomics we are taught in econ 1 and econ 101, all these complications are assumed away by restricting the analysis of price adjustment to a single market. In other words, as I have pointed out in a number of previous posts (here and here), standard microeconomics is built on macroeconomic foundations, and the currently fashionable demand for macroeconomics to be microfounded turns out to be based on question-begging circular reasoning. Partial equilibrium is a wonderful pedagogical device, and it is an essential tool in applied microeconomics, but its limitations are often misunderstood or ignored.

An early macroeconomic application of the theory of second is the statement by the quintessentially orthodox pre-Keynesian Cambridge economist Frederick Lavington who wrote in his book The Trade Cycle “the inactivity of all is the cause of the inactivity of each.” Each successive departure from the conditions for second-, third-, fourth-, and eventually nth-best sub-optima has additional negative feedback effects on the rest of the economy, moving it further and further away from a Pareto-optimal equilibrium with maximum output and full employment. The fewer people that are employed, the more difficult it becomes for anyone to find employment.

This insight was actually admirably, if inexactly, expressed by Say’s Law: supply creates its own demand. The cause of the cumulative contraction of output in a depression is not, as was often suggested, that too much output had been produced, but a breakdown of coordination in which disequilibrium spreads in epidemic fashion from market to market, leaving individual transactors unable to compensate by altering the terms on which they are prepared to supply goods and services. The idea that a partial-equilibrium response, a fall in money wages, can by itself remedy a general-disequilibrium disorder is untenable. Keynes and the Keynesians were therefore completely wrong to accuse Say of committing a fallacy in diagnosing the cause of depressions. The only fallacy lay in the assumption that market adjustments would automatically ensure the restoration of something resembling full-employment equilibrium.

The Pot Calls the Kettle Black

I had not planned to post anything today, but after coming across an article (“What the Fed Really Wants Is to Reduce Real Wages”) by Alex Pollock of AEI on Real Clear Markets this morning, I decided that I could not pass up this opportunity to expose a) a basic, but common and well-entrenched, error in macroeconomic reasoning, and b) the disturbingly hypocritical and deceptive argument in the service of which the faulty reasoning was deployed.

I start by quoting from Pollock’s article.

To achieve economic growth over time, prices have to change in order to adjust resource allocation to changing circumstances. This includes the price of work, or wages. Everybody does or should know this, and the Federal Reserve definitely knows it.

The classic argument for why central banks should create inflation as needed is that this causes real wages to fall, thus allowing the necessary downward adjustment, even while nominal wages don’t fall. Specifically, the argument goes like this: For employment and growth, wages sometimes have to adjust downward; people and politicians don’t like to have nominal wages fall– they are “sticky.” People are subject to Money Illusion and they don’t think in inflation-adjusted terms. Therefore create inflation to make real wages fall.

In an instructive meeting of the Federal Reserve Open Market Committee in July, 1996, the transcript of which has been released, the Fed took up the issue of “long-term inflation goals.” Promoting the cause of what ultimately became the Fed’s goal of 2% inflation forever, then-Fed Governor Janet Yellen made exactly the classic argument. “To my mind,” she said, “the most important argument for some low inflation rate is…that a little inflation lowers unemployment by facilitating adjustments in relative pay”-in other words, by lowering real wages. This reflects “a world where individuals deeply dislike nominal pay cuts,” she continued. “I think we are dealing here with a very deep-rooted property of the human psyche”-that is, Money Illusion.

In sum, since “workers resist and firms are unwilling to impose nominal pay cuts,” the Fed has to be able to reduce real wages instead by inflation.

But somehow the Fed never mentions that this is what it does. It apparently considers it a secret too deep for voters and members of Congress to understand. Perhaps it would be bad PR?

This summary of why some low rate of inflation may promote labor-0market flexibility is not far from the truth, but it does require some disambiguation. The first distinction to make is that while Janet Yellen was talking about adjustments in relative pay, presumably adjustments in wages both across different occupations and also across different geographic areas — a necessity even if the overall level of real wages is stable — Pollock simply talks about reducing real wages in general.

But there is a second, more subtle distinction to make here as well, and that distinction makes a big difference in how we understand what the Fed is trying to do. Suppose a reduction in real wages in general, or in the relative wages of some workers is necessary for labor-market equilibrium. To suggest that only reason to use inflation to reduce the need for nominal wage cuts is a belief in “Money Illusion” is deeply misleading. The concept of “Money Illusion” is only meaningful when applied to equilibrium states of the economy. Thus the absence of “Money Illusion” means that the equilibrium of the economy (under the assumption that the economy has a unique equilibrium — itself, a very questionable assumption, but let’s not get diverted from this discussion to an even messier and more complicated one) is the same regardless of how nominal prices are scaled up or down. It is entirely possible to accept that proposition (which seems to follow from fairly basic rationality assumptions) without also accepting that it is irrelevant whether real-wage reductions in response to changing circumstances are brought about by inflation or by nominal-wage cuts.

Since any discussion of changes in relative wages presumes that a transition from one equilibrium state to another equilibrium state is occurring, the absence of Money Illusion, being a property of equilibrium,  can’t tell us anything about whether the transition from one equilibrium state to another is more easily accomplished by way of nominal-wage cuts or by way of inflation. If, as a wide range of historical evidence suggests, real-wage reductions are more easily effected by way of inflation than by way of nominal-wage cuts, it is plausible to assume that minimizing nominal-wage cuts will ease the transition from the previous equilibrium to the new one.

Why is that? Here’s one way to think about it. The resistance to nominal-wage cuts implies that more workers will be unemployed initially if nominal wages are cut than if there is an inflationary strategy. It’s true that the unemployment is transitory (in some sense), but the transitory unemployment will be with reduced demand for other products, so the effect of unemployment of some workers is felt by other sectors adn other workers. This implication is not simply the multiplier effect of Keynesian economics, it is also a direct implication of the widely misunderstood Say’s Law, which says that supply creates its own demand. So if workers are more likely to become unemployed in the transition to an equilibrium with reduced real wages if the real-wage reduction is accomplished via a cut in nominal wages than if accomplished by inflation, then inflation reduces the reduction in demand associated with resistance to nominal-wage cuts. The point is simply that we have to consider not just the final destination, but also the route by which we get there. Sometimes the route to a destination may be so difficult and so dangerous, that we are better off not taking it and looking for an alternate route. Nominal wage cuts are very often a bad route by which to get to a new equilibrium.

That takes care of the error in macroeconomic reasoning, but let’s follow Pollock a bit further to get to the hypocrisy and deception.

This classic argument for inflation is of course a very old one. As Ludwig von Mises discussed clearly in 1949, the first reason for “the engineering of inflation” is: “To preserve the height of nominal wage rates…while real wage rates should rather sink.” But, he added pointedly, “neither the governments nor the literary champions of their policy were frank enough to admit openly that one of the main purposes of devaluation was a reduction in the height of real wage rates.” The current Fed is not frank enough to admit this fact either. Indeed, said von Mises, “they were anxious not to mention” this. So is the current Fed.

Nonetheless, the Fed feels it can pontificate on “inequality” and how real middle class incomes are not rising. Sure enough, with nominal wages going up 2% a year, if the Fed achieves its wish for 2% inflation, then indeed real wages will be flat. But Federal Reserve discussions of why they are flat at the very least can be described as disingenuous.

Actually, it is Pollock who is being disingenuous here. The Fed does not have a policy on real wages. Real wages are determined for the most part in free and competitive labor markets. In free and competitive labor markets, the equilibrium real wage is determined independently of the rate of inflation. Remember, there’s no Money Illusion. Minimizing nominal-wage cuts is not a policy aimed at altering equilibrium real wages, which are whatever market forces dictate, but of minimizing the costs associated with the adjustments in real wages in response to changing economic conditions.

I know that it’s always fun to quote Ludwig von Mises on inflation, but if you are going to quote Mises about how inflation is just a scheme designed to reduce real wages, you ought to at least be frank enough to acknowledge that what Mises was advocating was cutting nominal wages instead.

And it is worth recalling that even Mises recognized that nominal wages could not be reduced without limit to achieve equilibrium. In fact, Mises agreed with Keynes that it was a mistake for England in 1925 to restore sterling convertibility into gold at the prewar parity, because doing so required further painful deflation and nominal wage cuts. In other words, even Mises could understand that the path toward equilibrium mattered. Did that mean that Mises was guilty of believing in Money Illusion? Obviously not. And if the rate of deflation can matter to employment in the transition from one equilibrium to another, as Mises obviously conceded, why is it inconceivable that the rate of inflation might also matter?

So Pollock is trying to have his cake and eat it. He condemns the Fed for using inflation as a tool by which to reduce real wages. Actually, that is not what the Fed is doing, but, let us suppose that that’s what the Fed is doing, what alternative does Pollock have in mind? He won’t say. In other words, he’s the pot.

Who’s Afraid of Say’s Law?

There’s been a lot of discussion about Say’s Law in the blogosphere lately, some of it finding its way into the comments section of my recent post “What Does Keynesisan Mean,” in which I made passing reference to Keynes’s misdirected tirade against Say’s Law in the General Theory. Keynes wasn’t the first economist to make a fuss over Say’s Law. It was a big deal in the nineteenth century when Say advanced what was then called the Law of the Markets, pointing out that the object of all production is, in the end, consumption, so that all productive activity ultimately constitutes a demand for other products. There were extended debates about whether Say’s Law was really true, with Say, Ricardo, James and John Stuart Mill all weighing on in favor of the Law, and Malthus and the French economist J. C. L. de Sismondi arguing against it. A bit later, Karl Marx also wrote at length about Say’s Law, heaping his ample supply of scorn upon Say and his Law. Thomas Sowell’s first book, I believe drawn from the doctoral dissertation he wrote under George Stigler, was about the classical debates about Say’s Law.

The literature about Say’s Law is too vast to summarize in a blog post. Here’s my own selective take on it.

Say was trying to refute a certain kind of explanation of economic crises, and what we now would call cyclical or involuntary unemployment, an explanation attributing such unemployment to excess production for which income earners don’t have enough purchasing power in their pockets to buy. Say responded that the reason why income earners had supplied the services necessary to produce the available output was to earn enough income to purchase the output. This is the basic insight behind the famous paraphrase (I don’t know if it was Keynes’s paraphrase or someone else’s) of Say’s Law — supply creates its own demand. If it were instead stated as products or services are supplied only because the suppliers want to buy other products or services, I think that it would be more in sync than the standard formulation with Say’s intent. Another way to think about Say’s Law is as a kind of conservation law.

There were two famous objections made to Say’s Law: first, current supply might be offered in order to save for future consumption, and, second, current supply might be offered in order to add to holdings of cash. In either case, there could be current supply that is not matched by current demand for output, so that total current demand would be insufficient to generate full employment. Both these objections are associated with Keynes, but he wasn’t the first to make either of them. The savings argument goes back to the nineteenth century, and the typical response was that if there was insufficient current demand, because the desire to save had increased, the public deciding to reduce current expenditures on consumption, the shortfall in consumption demand would lead to an increase in investment demand driven by falling interest rates and rising asset prices. In the General Theory, Keynes proposed an argument about liquidity preference and a potential liquidity trap, suggesting a reason why the necessary adjustment in the rate of interest would not necessarily occur.

Keynes’s argument about a liquidity trap was and remains controversial, but the argument that the existence of money implies that Say’s Law can be violated was widely accepted. Indeed, in his early works on business-cycle theory, F. A. Hayek made the point, seemingly without embarrassment or feeling any need to justify it at length, that the existence of money implied a disconnect between overall supply and overall demand, describing money as a kind of loose joint in the economic system. This argument, apparently viewed as so trivial or commonplace by Hayek that he didn’t bother proving it or citing authority for it, was eventually formalized by the famous market-socialist economist (who, for a number of years was a tenured professor at that famous bastion of left-wing economics the University of Chicago) Oskar Lange who introduced a distinction between Walras’s Law and Say’s Law (“Say’s Law: A Restatement and Criticism”).

Walras’s Law says that the sum of all excess demands and excess supplies, evaluated at any given price vector, must identically equal zero. The existence of a budget constraint makes this true for each individual, and so, by the laws of arithmetic, it must be true for the entire economy. Essentially, this was a formalization of the logic of Say’s Law. However, Lange showed that Walras’s Law reduces to Say’s Law only in an economy without money. In an economy with money, Walras’s Law means that there could be an aggregate excess supply of all goods at some price vector, and the excess supply of goods would be matched by an equal excess demand for money. Aggregate demand would be deficient, and the result would be involuntary unemployment. Thus, according to Lange’s analysis, Say’s Law holds, as a matter of necessity, only in a barter economy. But in an economy with money, an excess supply of all real commodities was a logical possibility, which means that there could be a role for some type – the choice is yours — of stabilization policy to ensure that aggregate demand is sufficient to generate full employment. One of my regular commenters, Tom Brown, asked me recently whether I agreed with Nick Rowe’s statement: “the goal of good monetary policy is to try to make Say’s Law true.” I said that I wasn’t sure what the statement meant, thereby avoiding the need to go into a lengthy explanation about why I am not quite satisfied with that way of describing the goal of monetary policy.

There are at least two problems with Lange’s formulation of Say’s Law. The first was pointed out by Clower and Leijonhufvud in their wonderful paper (“Say’s Principle: What It Means and Doesn’t Mean” reprinted here and here) on what they called Say’s Principle in which they accepted Lange’s definition of Say’s Law, while introducing the alternative concept of Say’s Principle as the supply-side analogue of the Keynesian multiplier. The key point was to note that Lange’s analysis was based on the absence of trading at disequilibrium prices. If there is no trading at disequilibrium prices, because the Walrasian auctioneer or clearinghouse only processes information in a trial-and-error exercise aimed at discovering the equilibrium price vector, no trades being executed until the equilibrium price vector has been discovered (a discovery which, even if an equilibrium price vector exists, may not be made under any price-adjustment rule adopted by the auctioneer, rational expectations being required to “guarantee” that an equilibrium price vector is actually arrived at, sans auctioneer), then, indeed, Say’s Law need not obtain in notional disequilibrium states (corresponding to trial price vectors announced by the Walrasian auctioneer or clearinghouse). The insight of Clower and Leijonhufvud was that in a real-time economy in which trading is routinely executed at disequilibrium prices, transactors may be unable to execute the trades that they planned to execute at the prevailing prices. But when planned trades cannot be executed, trading and output contract, because the volume of trade is constrained by the lesser of the amount supplied and the amount demanded.

This is where Say’s Principle kicks in; If transactors do not succeed in supplying as much as they planned to supply at prevailing prices, then, depending on the condition of their balances sheets, and the condition of credit markets, transactors may have to curtail their demands in subsequent periods; a failure to supply as much as had been planned last period will tend reduce demand in this period. If the “distance” from equilibrium is large enough, the demand failure may even be amplified in subsequent periods, rather than damped. Thus, Clower and Leijonhufvud showed that the Keynesian multiplier was, at a deep level, really just another way of expressing the insight embodied in Say’s Law (or Say’s Principle, if you insist on distinguishing what Say meant from Lange’s reformulation of it in terms of Walrasian equilibrium).

I should add that, as I have mentioned in an earlier post, W. H. Hutt, in a remarkable little book, clarified and elaborated on the Clower-Leijonhufvud analysis, explaining how Say’s Principle was really implicit in many earlier treatments of business-cycle phenomena. The only reservation I have about Hutt’s book is that he used it to wage an unnecessary polemical battle against Keynes.

At about the same time that Clower and Leijonhufvud were expounding their enlarged view of the meaning and significance of Say’s Law, Earl Thompson showed that under “classical” conditions, i.e., a competitive supply of privately produced bank money (notes and deposits) convertible into gold, Say’s Law in Lange’s narrow sense, could also be derived in a straightforward fashion. The demonstration followed from the insight that when bank money is competitively issued, it is accomplished by an exchange of assets and liabilities between the bank and the bank’s customer. In contrast to the naïve assumption of Lange (adopted as well by his student Don Patinkin in a number of important articles and a classic treatise) that there is just one market in the monetary sector, there are really two markets in the monetary sector: a market for money supplied by banks and a market for money-backing assets. Thus, any excess demand for money would be offset not, as in the Lange schema, by an excess supply of goods, but by an excess supply of money-backing services. In other words, the public can increase their holdings of cash by giving their IOUs to banks in exchange for the IOUs of the banks, the difference being that the IOUs of the banks are money and the IOUs of customers are not money, but do provide backing for the money created by banks. The market is equilibrated by adjustments in the quantity of bank money and the interest paid on bank money, with no spillover on the real sector. With no spillover from the monetary sector onto the real sector, Say’s Law holds by necessity, just as it would in a barter economy.

A full exposition can be found in Thompson’s original article. I summarized and restated its analysis of Say’s Law in my 1978 1985 article on classical monetary theory and in my book Free Banking and Monetary Reform. Regrettably, I did not incorporate the analysis of Clower and Leijonhufvud and Hutt into my discussion of Say’s Law either in my article or in my book. But in a world of temporary equilibrium, in which future prices are not correctly foreseen by all transactors, there are no strict intertemporal budget constraints that force excess demands and excess supplies to add up to zero. In short, in such a world, things can get really messy, which is where the Clower-Leijonhufvud-Hutt analysis can be really helpful in sorting things out.

What Does “Keynesian” Mean?

Last week Simon Wren-Lewis wrote a really interesting post on his blog trying to find the right labels with which to identify macroeconomists. Simon, rather disarmingly, starts by admitting the ultimate futility of assigning people labels; reality is just too complicated to conform to the labels that we invent to help ourselves make sense of reality. A good label can provide us with a handle with which to gain a better grasp on a messy set of observations, but it is not the reality. And if you come up with one label, I may counter with a different one. Who’s to say which label is better?

At any rate, as I read through Simon’s post I found myself alternately nodding my head in agreement and shaking my head in disagreement. So staying in the spirit of fun in which Simon wrote his post, I will provide a commentary on his labels and other pronouncements. If the comments are weighted on the side of disagreement, well, that’s what makes blogging fun, n’est-ce pas?

Simon divides academic researchers into two groups (mainstream and heterodox) and macroeconomic policy into two approaches (Keynesian and anti-Keynesian). He then offers the following comment on the meaning of the label Keynesian.

Just think about the label Keynesian. Any sensible definition would involve the words sticky prices and aggregate demand. Yet there are still some economists (generally not academics) who think Keynesian means believing fiscal rather than monetary policy should be used to stabilise demand. Fifty years ago maybe, but no longer. Even worse are non-economists who think being a Keynesian means believing in market imperfections, government intervention in general and a mixed economy. (If you do not believe this happens, look at the definition in Wikipedia.)

Well, as I pointed out in a recent post, there is nothing peculiarly Keynesian about the assumption of sticky prices, especially not as a necessary condition for an output gap and involuntary unemployment. So if Simon is going to have to work harder to justify his distinction between Keynesian and anti-Keynesian. In a comment on Simon’s blog, Nick Rowe pointed out just this problem, asking in particular why Simon could not substitute a Monetarist/anti-Monetarist dichotomy for the Keynesian/anti-Keynesian one.

The story gets more complicated in Simon’s next paragraph in which he describes his dichotomy of academic research into mainstream and heterodox.

Thanks to the microfoundations revolution in macro, mainstream macroeconomists speak the same language. I can go to a seminar that involves an RBC model with flexible prices and no involuntary unemployment and still contribute and possibly learn something. Equally an economist like John Cochrane can and does engage in meaningful discussions of New Keynesian theory (pdf).

In other words, the range of acceptable macroeconomic models has been drastically narrowed. Unless it is microfounded in a dynamic stochastic general equilibrium model, a model does not qualify as “mainstream.” This notion of microfoundation is certainly not what Edmund Phelps meant by “microeconomic foundations” when he edited his famous volume Microeconomic Foundations of Employment and Inflation Theory, which contained, among others, Alchian’s classic paper on search costs and unemployment and a paper by the then not so well-known Robert Lucas and his early collaborator Leonard Rapping. Nevertheless, in the current consensus, it is apparently the New Classicals that determine what kind of model is acceptable, while New Keynesians are allowed to make whatever adjustments, mainly sticky wages, they need to derive Keynesian policy recommendations. Anyone who doesn’t go along with this bargain is excluded from the mainstream. Simon may not be happy with this state of affairs, but he seems to have made peace with it without undue discomfort.

Now many mainstream macroeconomists, myself included, can be pretty critical of the limitations that this programme can place on economic thinking, particularly if it is taken too literally by microfoundations purists. But like it or not, that is how most macro research is done nowadays in the mainstream, and I see no sign of this changing anytime soon. (Paul Krugman discusses some reasons why here.) My own view is that I would like to see more tolerance and a greater variety of modelling approaches, but a pragmatic microfoundations macro will and should remain the major academic research paradigm.

Thus, within the mainstream, there is no basic difference in how to create a macroeconomic model. The difference is just in how to tweak the model in order to derive the desired policy implication.

When it comes to macroeconomic policy, and keeping to the different language idea, the only significant division I see is between the mainstream macro practiced by most economists, including those in most central banks, and anti-Keynesians. By anti-Keynesian I mean those who deny the potential for aggregate demand to influence output and unemployment in the short term.

So, even though New Keynesians have learned how to speak the language of New Classicals, New Keynesians can console themselves in retaining the upper hand in policy discussions. Which is why in policy terms, Simon chooses a label that is at least suggestive of a certain Keynesian primacy, the other side being defined in terms of their opposition to Keynesian policy. Half apologetically, Simon then asks: “Why do I use the term anti-Keynesian rather than, say, New Classical?” After all, it’s the New Classical model that’s being tweaked. Simon responds:

Partly because New Keynesian economics essentially just augments New Classical macroeconomics with sticky prices. But also because as far as I can see what holds anti-Keynesians together isn’t some coherent and realistic view of the world, but instead a dislike of what taking aggregate demand seriously implies.

This explanation really annoyed Steve Williamson who commented on Simon’s blog as follows:

Part of what defines a Keynesian (new or old), is that a Keynesian thinks that his or her views are “mainstream,” and that the rest of macroeconomic thought is defined relative to what Keynesians think – Keynesians reside at the center of the universe, and everything else revolves around them.

Simon goes on to explain what he means by the incoherence of the anti-Keynesian view of the world, pointing out that the Pigou Effect, which supposedly invalidated Keynes’s argument that perfect wage and price flexibility would not eventually restore full employment to an economy operating at less than full employment, has itself been shown not to be valid. And then Simon invokes that old standby Say’s Law.

Second, the evidence that prices are not flexible is so overwhelming that you need something else to drive you to ignore this evidence. Or to put it another way, you need something pretty strong for politicians or economists to make the ‘schoolboy error’ that is Says Law, which is why I think the basis of the anti-Keynesian view is essentially ideological.

Here, I think, Simon is missing something important. It was a mistake on Keynes’s part to focus on Say’s Law as the epitome of everything wrong with “classical economics.” Actually Say’s Law is a description of what happens in an economy when trading takes place at disequilibrium prices. At disequilibrium prices, potential gains from trade are left on the table. Not only are they left on the table, but the effects can be cumulative, because the failure to supply implies a further failure to demand. The Keynesian spending multiplier is the other side of the coin of the supply-side contraction envisioned by Say. Even infinite wage and price flexibility may not help an economy in which a lot of trade is occurring at disequilibrium prices.

The microeconomic theory of price adjustment is a theory of price adjustment in a single market. It is a theory in which, implicitly, all prices and quantities, but a single price-quantity pair are in equilibrium. Equilibrium in that single market is rapidly restored by price and quantity adjustment in that single market. That is why I have said that microeconomics rests on a macroeconomic foundation, and that is why it is illusory to imagine that macroeconomics can be logically derived from microfoundations. Microfoundations, insofar as they explain how prices adjust, are themselves founded on the existence of a macroeconomic equilibrium. Founding macroeconomics on microfoundations is just a form of bootstrapping.

If there is widespread unemployment, it may indeed be that wages are too high, and that a reduction in wages would restore equilibrium. But there is no general presumption that unemployment will be cured by a reduction in wages. Unemployment may be the result of a more general dysfunction in which all prices are away from their equilibrium levels, in which case no adjustment of the wage would solve the problem, so that there is no presumption that the current wage exceeds the full-equilibrium wage. This, by the way, seems to me to be nothing more than a straightforward implication of the Lipsey-Lancaster theory of second best.

Hawtrey on the Keynesian Explanation of Unemployment

Here is a tidbit I just found the end of R. G. Hawtrey’s long chapter on the General Theory in his volume Capital and Employment, (second edition, 1952) pp. 218-19.

Unemployment in Great Britain seemed at the time [1935 when Keynes finished writing the General Theory] to be chronic: the number of unemployed had never fallen below a million since 1921. Keynes was looking for an explanation of chronic unemployment, but it was hardly plausible to attribute it to the low long-term rate of interest [i.e., to a liquidity trap]. The yield of Government securities had been exceptionally high till the Conversion of 1932.

And in reality there is no school of thought for which the explanation of unemployment presents any difficulty. If wages are too high for full employment, and resist reduction, unemployment is bound to result. Adam Smith held that for a growing population a corresponding growth of capital was essential to maintain wages at or above subsistence level; the penalty for the failure of capital to grow was unemployment as well as starvation. For his successors it was self-evident that the employment afforded by the “wage fund” was inversely proportional to the rate of wages, and, when the theory of the wage fund was superseded by that of the marginal yield of labour, it was no less self-evident that a wage-level held above marginal yield would prevent full employment. Say’s loi des debouches declared that production generated its own demand; but if for any reason production was below capacity and there was unemployment, the demand generated would be no more than sufficient to absorb output at that level.

What I find especially interesting in the passage is Hawtrey’s correct understanding of Say’s Law, so that it constitutes not, as Keynes supposed, an assertion that unemployment is impossible, but an explanation of how aggregate demand is itself just the flip side of aggregate supply. Contractions of supply can be cumulative. It’s not just Keynesians who forget this essential point. RBC theorists and others who model the business cycle as a general-equilibrium phenomenon miss an essential feature of what constitutes the business cycle.


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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