Posts Tagged 'von Mises'

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.


Real and Pseudo Gold Standards: Could Friedman Tell the Difference?

One of the first academic papers by Milton Friedman that I read was “Real and Pseudo Gold Standards.” It’s an interesting paper presented to the Mont Pelerin Society in September 1961 and published in the Journal of Law and Economics in October 1961. That it was published in the Journal of Law and Economics, then edited by Friedman’s colleague at Chicago (and fellow Mont Pelerin member) Ronald Coase, is itself interesting, that estimable journal hardly being an obvious place to publish research on monetary economics. But the point of the paper was not to advance new theoretical insights about monetary theory, though he did provide a short preview of his critique of Fed policy in the 1920-21 Depression and in the Great Depression that he and Anna Schwartz would make in their soon to be published Monetary History of the United States, but to defend Friedman’s pro-fiat money position as a respectable alternative among the libertarians and classical liberals with whom Friedman had allied himself in the Mont Pelerin Society.

Although many members of the Mont Pelerin Society, including Hayek himself, as well as Friedman, Fritz Machlup and Lionel Robbins no longer supported the gold standard, their reasons for doing so were largely pragmatic, believing that whatever its virtues, the gold standard was no longer a realistic or even a desirable option as a national or an international monetary system. But there was another, perhaps more numerous, faction within the Mont Pelerin Society and the wider libertarian/ classical-liberal community, that disdained any monetary system other than the gold standard. The intellectual leader of this group was of course the soul of intransigence, the unyieldingly stubborn Ludwig von Mises, notably supported by the almost equally intransigent French economist Jacques Rueff, whose attachment to gold was so intense that Charles de Gaulle, another in a long line of French politicians enchanted by the yellow metal, had chosen Rueff as his personal economic adviser.

What Friedman did in this essay was not to engage with von Mises on the question of the gold standard; Friedman was realistic enough to understand that one could not reason with von Mises, who anyway regarded Friedman, as he probably did most of the members of the Mont Pelerin Society, as hardly better than a socialist. Instead, his strategy was to say that there is only one kind of real gold standard – presumably the kind favored by von Mises, whose name went unmentioned by Friedman, anything else being a pseudo-gold standard — in reality, nothing but a form of price fixing in which the government sets the price of gold and manages the gold market to prevent the demand for gold from outstripping the supply. While Friedman acknowledged that a real gold standard could be defended on strictly libertarian grounds, he argued that a pseudo-gold standard could not, inasmuch as it requires all sorts of market interventions, especially restrictions on the private ownership of gold that were then in place. What Friedman was saying, in effect, to the middle group in the Mont Pelerin Society was the only alternatives for liberals and libertarians were a gold standard of the Mises type or his preference: a fiat standard with flexible exchange rates.

Here is how he put it:

It is vitally important for the preservation and promotion of a free society that we recognize the difference between a real and pseudo gold standard. War aside, nothing that has occurred in the past half-century has, in my view, done more weaken and undermine the public’s faith in liberal principles than the pseudo gold standard that has intermittently prevailed and the actions that have been taken in its name. I believe that those of us who support it in the belief that it either is or will tend to be a real gold standard are mistakenly fostering trends the outcome of which they will be among the first to deplore.

This is a sweeping charge, so let me document it by a few examples which will incidentally illustrate the difference between a real and a pseudo gold standard before turning to an explicit discussion of the difference.

So what were Friedman’s examples of a pseudo gold standard? He offered five. First, US monetary policy after World War I, in particular the rapid inflation of 1919 and the depression of 1920-21. Second, US monetary policy in the 1920s and the British return to gold. Third, US monetary policy in the 1931-33 period. Fourth the U.S. nationalization of gold in 1934. And fifth, the International Monetary Fund and post-World War II exchange-rate policy.

Just to digress for a moment, I will admit that when I first read this paper as an undergraduate I was deeply impressed by his introductory statement, but found much of the rest of the paper incomprehensible. Still awestruck by Friedman, who, I then believed, was the greatest economist alive, I attributed my inability to follow what he was saying to my own intellectual shortcomings. So I have to admit to taking a bit of satisfaction in now being able to demonstrate that Friedman literally did not know what he was talking about.

US Monetary Policy after World War I

Friedman’s discussion of monetary policy after WWI begins strangely as if he were cutting and pasting from another source without providing any background to the discussion. I suspected that he might have cut and pasted from the Monetary History, but that turned out not to be the case. However, I did find that this paragraph (and probably a lot more] was included in testimony he gave to the Joint Economic Committee.

Nearly half of the monetary expansion in the United States came after the end of the war, thanks to the acquiescence of the Federal Reserve System in the Treasury’s desire to avoid a fall in the price of government securities. This expansion, with its accompanying price inflation, led to an outflow of gold despite the great demand for United States goods from a war-ravaged world and despite the departure of most countries from any fixed parity between their currencies and either gold or the dollar.

Friedman, usually a very careful writer, refers to “half of the monetary expansion” without identifying in any way “the monetary expansion” that he is referring to, leaving it to the reader to conjecture whether he is talking about the monetary expansion that began with the start of World War I in 1914 or the monetary expansion that began with US entry into the war in 1917 or the monetary expansion associated with some other time period. Friedman then goes on to describe the transition from inflation to deflation.

Beginning in late 1919, then more sharply in January 1920 and May 1920, the Federal Reserve System took vigorous deflationary steps that produced first a slackening of the growth of money and then a sharp decline. These brought in their train a collapse in wholesale prices and a severe economic contraction. The near halving of wholesale prices in a twelve month period was by all odds the most rapid price decline ever experienced in the United States before or since. It was not of course confined to the United States but spread to all countries whose money was linked to the dollar either by having a fixed price in terms of gold or by central bank policies directed at maintaining rigid or nearly rigid exchange rates.

That is a fair description of what happened after the Fed took vigorous deflationary steps, notably raising its discount rate to 6%. What Friedman neglects to point out is that there was no international gold standard (real or pseudo) immediately after the war, because only the United States was buying and selling gold at a legally established gold parity. Friedman then goes on to compare the pseudo gold standard under which the US was then operating with what would have happened under a real gold standard.

Under a real gold standard, the large inflow of gold up to the entry of the United States into the war would have produced a price rise to the end of the war similar to that actually experienced.

Now, aside from asserting that under a real gold standard, gold is used as money, and that under a pseudo gold standard, government is engaged in fixing the price of gold, Friedman has not told us how to distinguish between a real and a pseudo gold standard. So it is certainly fair to ask whether in the passage just quoted Friedman meant that the gold standard under which the US was operating when there was a large inflow of gold before entering the war was real or pseudo. His use of the subjunctive verb “would have produced” suggests that he believed that the gold standard was pseudo, not real. But then he immediately says that, under the real gold standard, the “price rise to the end of the war” would have been “similar to that actually experienced.” So take your pick.

Evidently, the difference between a real and a pseudo gold standard became relevant only after the war was over.

But neither the postwar rise nor the subsequent collapse would have occurred. Instead, there would have been an earlier and milder price decline as the belligerent nations returned to a peacetime economy. The postwar increase in the stock of money occurred only because the Reserve System had been given discretionary power to “manage” the stock of money, and the subsequent collapse occurred only because this power to manage the money had been accompanied by gold reserve requirements as one among several masters the System was instructed to serve.

That’s nice, but Friedman has not even suggested, much less demonstrated in any way, how all of this is related to the difference between a real and a pseudo gold standard. Was there any postwar restriction on the buying or selling of gold by private individuals? Friedman doesn’t say. All he can come up with is the idea that the Fed had been given “discretionary power to ‘manage’ the stock of money.” Who gave the Fed this power? And how was this power exercised? He refers to gold reserve requirements, but gold reserve requirements – whether they were a good idea or not is not my concern here — existed before the Fed came into existence.

If the Fed had unusual powers after World War I, those powers were not magically conferred by some unidentified entity, but by the circumstance that the US had accumulated about 40% of the world’s monetary gold reserves during World War I, and was the only country, after the war, that was buying and selling gold freely at a fixed price ($20.67 an ounce). The US was therefore in a position to determine the value of gold either by accumulating more gold or by allowing an efflux of gold from its reserves. Whether the US was emitting or accumulating gold depended on the  interest-rate policy of the Federal Reserve. It is true that the enormous control the US then had over the value of gold was a unique circumstance in world history, but the artificial and tendentious distinction between a real and a pseudo gold standard has absolutely nothing to do with the inflation in 1919 or the deflation in 1920-21.

US Monetary Policy in the 1920s and Britain’s Return to Gold

In the next section Friedman continues his critical review of Fed policy in the 1920s, defending the Fed against the charge (a staple of Austrian Business Cycle Theory and other ill-informed and misguided critics) that it fueled a credit boom during the 1920s. On the contrary, Friedman shows that Fed policy was generally on the restrictive side.

I do not myself believe that the 1929-33 contraction was an inevitable result of the monetary policy of the 1920s or even owed much to it. What was wrong was the policy followed from 1929 to 1933. . . . But internationally, the policy was little short of catastrophic. Much has been made of Britain’s mistake in returning to gold in 1925 at a parity that overvalued the pound. I do not doubt that this was a mistake – but only because the United States was maintaining a pseudo gold standard. Had the United States been maintaining a real gold standard, the stock of money would have risen more in the United States than it did, prices would have been stable or rising instead of declining, the United States would have gained less gold or lost some, and the pressure on the pound would have been enormously eased. As it was by sterilizing gold, the United States forced the whole burden of adapting to gold movements on other countries. When, in addition, France adopted a pseudo gold standard at a parity that undervalued the franc and proceeded also to follow a gold sterilization policy, the combined effect was to make Britain’s position untenable.

This is actually a largely coherent paragraph, more or less correctly diagnosing the adverse consequences of an overly restrictive policy adopted by the Fed for most of the 1920s. What is not coherent is the attempt to attribute policy choices of which Friedman (and I) disapprove to the unrealness of the gold standard. There was nothing unreal about the gold standard as it was operated by the Fed in the 1920s. The Fed stood ready to buy and sell gold at the official price, and Friedman does not even suggest that there was any lapse in that commitment.

So what was the basis for Friedman’s charge that the 1920s gold standard was fake or fraudulent? Friedman says that if there had been a real, not a pseudo, gold standard, “the stock of money would have risen more in the United States than it did, prices would have been stable or rising instead of declining,” and the US “would have gained less gold or lost some.” That this did not happen, Friedman attributes to a “gold sterilization policy” followed by the US. Friedman is confused on two levels. First, he seems to believe that the quantity of money in the US was determined by the Fed. However, under a fixed-exchange-rate regime, the US money supply was determined endogenously via the balance of payments. What the Fed could determine by setting its interest rate was simply whether gold would flow into or out of US reserves. The level of US prices was determined by the internationally determined value of gold. Whether gold was flowing into or out of US reserves, in turn, determined the value of gold was rising or falling, and, correspondingly, whether prices in terms of gold were falling or rising. If the Fed had set interest rates somewhat lower than they did, gold would have flowed out of US reserves, the value of gold would have declined and prices in terms of gold would have risen, thereby easing deflationary pressure on Great Britain occasioned by an overvalued sterling-dollar exchange rate. I have no doubt that the Fed was keeping its interest rate too high for most of the 1920s, but why a mistaken interest-rate policy implies a fraudulent gold standard is not explained. Friedman, like his nemesis von Mises, simply asserted his conclusion or his definition, and expected his listeners and readers to nod in agreement.

US Monetary Policy in the 1931-33 Period

In this section Friedman undertakes his now familiar excoriation of Fed inaction to alleviate the banking crises that began in September 1931 and continued till March 1933. Much, if not all, of Friedman’s condemnation of the Fed is justified, though his failure to understand the international nature of the crisis caused him to assume that the Fed could have prevented a deflation caused by a rising value of gold simply by preventing bank failures. There are a number of logical gaps in that argument, and Friedman failed to address them, simply assuming that US prices were determined by the US money stock even though the US was still operating on the gold standard and the internationally determined value of gold was rising.

But in condemning the Fed’s policy in failing to accommodate an internal drain at the first outbreak of domestic banking crises in September 1931, Friedman observes:

Prior to September 1931, the System had been gaining gold, the monetary gold stock was at an all-time high, and the System’s gold reserve ratio was far above its legal minimum – a reflection of course of its not having operated in accordance with a real gold standard.

Again Friedman is saying that the criterion for identifying whether the gold standard is real or fraudulent is whether policy makers make the correct policy decision, if they make a mistake, it means that the gold standard in operation is no longer a real gold standard; it has become a pseudo gold standard.

The System had ample reserves to meet the gold outflow without difficulty and without resort to deflationary measures. And both its own earlier policy and the classical gold-standard rules as enshrined by Bagehot called for its doing so: the gold outflow was strictly speculative and motivated by fear that the United States would go off gold; the outflow had no basis in any trade imbalance; it would have exhausted itself promptly if all demands had been met.

Thus, Friedman, who just three pages earlier had asserted that the gold standard became a pseudo gold standard when the managers of the Federal Reserve System were given discretionary powers to manage the stock of money, now suggests that a gold standard can also be made a pseudo gold standard if the monetary authority fails to exercise its discretionary powers.

US Nationalization of Gold in 1934

The nationalization of gold by FDR effectively ended the gold standard in the US. Nevertheless, Friedman was so enamored of the distinction between real and pseudo gold standards that he tried to portray US monetary arrangements after the nationalization of gold as a pseudo gold standard even though the gold standard had been effectively nullified. But at least, the distinction between what is real and what is fraudulent about the gold standard is now based on an objective legal and institutional fact: the general right to buy gold from (or sell gold to) the government at a fixed price whenever government offices are open for business. Similarly after World War II, only the US government had any legal obligation to sell gold at the official price, but there was only a very select group of individuals and governments who were entitled to buy gold from the US government. Even to call such an arrangement a pseudo gold standard seems like a big stretch, but there is nothing seriously wrong with calling it a pseudo gold standard. But I have no real problem with Friedman’s denial that there was a true gold standard in operation after the nationalization of gold in 1934.

I would also agree that there really was not a gold standard in operation after the US entered World War I, because the US stopped selling gold after the War started. In fact, a pseudo gold standard is a good way to characterize the status of the gold standard during World War I, because the legal price of gold was not changed in any of the belligerent countries, but it was understood that for a private citizen to try to redeem currency for gold at the official price would be considered a reprehensible act, something almost no one was willing to do. But to assert, as Friedman did, that even when the basic right to buy gold at the official price was routinely exercised, a real gold standard was not necessarily in operation, is simply incoherent, or sophistical. Take your pick.

How to Think about Own Rates of Interest

Phil Pilkington has responded to my post about the latest version of my paper (co-authored by Paul Zimmerman) on the Sraffa-Hayek debate about the natural rate of interest. For those of you who haven’t been following my posts on the subject, here’s a quick review. Almost three years ago I wrote a post refuting Sraffa’s argument that Hayek’s concept of the natural rate of interest is incoherent, there being a multiplicity of own rates of interest in a barter economy (Hayek’s benchmark for the rate of interest undisturbed by monetary influences), which makes it impossible to identify any particular own rate as the natural rate of interest.

Sraffa maintained that if there are many own rates of interest in a barter economy, none of them having a claim to priority over the others, then Hayek had no basis for singling out any particular one of them as the natural rate and holding it up as the benchmark rate to guide monetary policy. I pointed out that Ludwig Lachmann had answered Sraffa’s attack (about 20 years too late) by explaining that even though there could be many own rates for individual commodities, all own rates are related by the condition that the cost of borrowing in terms of all commodities would be equalized, differences in own rates reflecting merely differences in expected appreciation or depreciation of the different commodities. Different own rates are simply different nominal rates; there is a unique real own rate, a point demonstrated by Irving Fisher in 1896 in Appreciation and Interest.

Let me pause here for a moment to explain what is meant by an own rate of interest. It is simply the name for the rate of interest corresponding to a loan contracted in terms of a particular commodity, the borrower receiving the commodity now and repaying the lender with the same commodity when the term of the loan expires. Sraffa correctly noted that in equilibrium arbitrage would force the terms of such a loan (i.e., the own rate of interest) to equal the ratio of the current forward price of the commodity to its current spot price, buying spot and selling forward being essentially equivalent to borrowing and repaying.

Now what is tricky about Sraffa’s argument against Hayek is that he actually acknowledges at the beginning of his argument that in a stationary equilibrium, presumably meaning that prices remain at their current equilibrium levels over time, all own rates would be equal. In fact if prices remain (and are expected to remain) constant period after period, the ratio of forward to spot prices would equal unity for all commodities implying that the natural rate of interest would be zero. Sraffa did not make that point explicitly, but it seems to be a necessary implication of his analysis. (This implication seems to bear on an old controversy in the theory of capital and interest, which is whether the rate of interest would be positive in a stationary equilibrium with constant real income). Schumpeter argued that the equilibrium rate of interest would be zero, and von Mises argued that it would be positive, because time preference implying that the rate of interest is necessarily always positive is a kind of a priori praxeological law of nature, the sort of apodictic gibberish to which von Mises was regrettably predisposed. The own-rate analysis supports Schumpeter against Mises.

So to make the case against Hayek, Sraffa had to posit a change, a shift in demand from one product to another, that disrupts the pre-existing equilibrium. Here is the key passage from Sraffa:

Suppose there is a change in the distribution of demand between various commodities; immediately some will rise in price, and others will fall; the market will expect that, after a certain time, the supply of the former will increase, and the supply of the latter fall, and accordingly the forward price, for the date on which equilibrium is expected to be restored, will be below the spot price in the case of the former and above it in the case of the latter; in other words, the rate of interest on the former will be higher than on the latter. (p. 50)

This is a difficult passage, and in previous posts, and in my paper with Zimmerman, I did not try to parse this passage. But I am going to parse it now. Assume that demand shifts from tomatoes to cucumbers. In the original equilibrium, let the prices of both be $1 a pound. With a zero own rate of interest in terms of both tomatoes and cucumbers, you could borrow a pound of tomatoes today and discharge your debt by repaying the lender a pound of tomatoes at the expiration of the loan. However, after the demand shift, the price of tomatoes falls to, say, $0.90 a pound, and the price of cucumbers rises to, say, $1.10 a pound. Sraffa posits that the price changes are temporary, not because the demand shift is temporary, but because the supply curves of tomatoes and cucumbers are perfectly elastic at $1 a pound. However, supply does not adjust immediately, so Sraffa believes that there can be a temporary deviation from the long-run equilibrium prices of tomatoes and cucumbers.

The ratio of the forward prices to the spot prices tells you what the own rates are for tomatoes and cucumbers. For tomatoes, the ratio is 1/.9, implying an own rate of 11.1%. For cucumbers the ratio is 1/1.1, implying an own rate of -9.1%. Other prices have not changed, so all other own rates remain at 0. Having shown that own rates can diverge, Sraffa thinks that he has proven Hayek’s concept of a natural rate of interest to be a nonsense notion. He was mistaken.

There are at least two mistakes. First, the negative own rate on cucumbers simply means that no one will lend in terms of cucumbers for negative interest when other commodities allow lending at zero interest. It also means that no one will hold cucumbers in this period to sell at a lower price in the next period than the cucumbers would fetch in the current period. Cucumbers are a bad investment, promising a negative return; any lending and investing will be conducted in terms of some other commodity. The negative own rate on cucumbers signifies a kind of corner solution, reflecting the impossibility of transporting next period’s cucumbers into the present. If that were possible cucumber prices would be equal in the present and the future, and the cucumber own rate would be equal to all other own rates at zero. But the point is that if any lending takes place, it will be at a zero own rate.

Second, the positive own rate on tomatoes means that there is an incentive to lend in terms of tomatoes rather than lend in terms of other commodities. But as long as it is possible to borrow in terms of other commodities at a zero own rate, no one borrows in terms of tomatoes. Thus, if anyone wanted to lend in terms of tomatoes, he would have to reduce the rate on tomatoes to make borrowers indifferent between borrowing in terms of tomatoes and borrowing in terms of some other commodity. However, if tomatoes today can be held at zero cost to be sold at the higher price prevailing next period, currently produced tomatoes would be sold in the next period rather than sold today. So if there were no costs of holding tomatoes until the next period, the price of tomatoes in the next period would be no higher than the price in the current period. In other words, the forward price of tomatoes cannot exceed the current spot price by more than the cost of holding tomatoes until the next period. If the difference between the spot and the forward price reflects no more than the cost of holding tomatoes till the next period, then, as Keynes showed in chapter 17 of the General Theory, the own rates are indeed effectively equalized after appropriate adjustment for storage costs and expected appreciation.

Thus, it was Keynes, who having selected Sraffa to review Hayek’s Prices and Production in the Economic Journal, of which Keynes was then the editor, adapted Sraffa’s own rate analysis in the General Theory, but did so in a fashion that, at least partially, rehabilitated the very natural-rate analysis that had been the object of Sraffa’s scorn in his review of Prices and Production. Keynes also rejected the natural-rate analysis, but he did so not because it is nonsensical, but because the natural rate is not independent of the level of employment. Keynes’s argument that the natural rate depends on the level of employment seems to me to be inconsistent with the idea that the IS curve is downward sloping. But I will have to think about that a bit and reread the relevant passage in the General Theory and perhaps revisit the point in a future post.

 UPDATE (07/28/14 13:02 EDT): Thanks to my commenters for pointing out that my own thinking about the own rate of interest was not quite right. I should have defined the own rate in terms of a real numeraire instead of $, which was a bit of awkwardness that I should have fixed before posting. I will try to publish a corrected version of this post later today or tomorrow. Sorry for posting without sufficient review and revision.

UPDATE (08/04/14 11:38 EDT): I hope to post the long-delayed sequel to this post later today. A number of personal issues took precedence over posting, but I also found it difficult to get clear on several minor points, which I hope that I have now resolved adequately, for example I found that defining the own rate in terms of a real numeraire was not really the source of my problem with this post, though it was a useful exercise to work through. Anyway, stay tuned.

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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