Archive for the 'Irving Fisher' Category

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.

A New Version of my Paper (with Paul Zimmerman) on the Hayek-Sraffa Debate Is Available on SSRN

One of the good things about having a blog (which I launched July 5, 2011) is that I get comments about what I am writing about from a lot of people that I don’t know. One of my most popular posts – it’s about the sixteenth most visited — was one I wrote, just a couple of months after starting the blog, about the Hayek-Sraffa debate on the natural rate of interest. Unlike many popular posts, to which visitors are initially drawn from very popular blogs that linked to those posts, but don’t continue to drawing a lot of visitors, this post initially had only modest popularity, but still keeps on drawing visitors.

That post also led to a collaboration between me and my FTC colleague Paul Zimmerman on a paper “The Sraffa-Hayek Debate on the Natural Rate of Interest” which I presented two years ago at the History of Economics Society conference. We have now finished our revisions of the version we wrote for the conference, and I have just posted the new version on SSRN and will be submitting it for publication later this week.

Here’s the abstract posted on the SSRN site:

Hayek’s Prices and Production, based on his hugely successful lectures at LSE in 1931, was the first English presentation of Austrian business-cycle theory, and established Hayek as a leading business-cycle theorist. Sraffa’s 1932 review of Prices and Production seems to have been instrumental in turning opinion against Hayek and the Austrian theory. A key element of Sraffa’s attack was that Hayek’s idea of a natural rate of interest, reflecting underlying real relationships, undisturbed by monetary factors, was, even from Hayek’s own perspective, incoherent, because, without money, there is a multiplicity of own rates, none of which can be uniquely identified as the natural rate of interest. Although Hayek’s response failed to counter Sraffa’s argument, Ludwig Lachmann later observed that Keynes’s treatment of own rates in Chapter 17 of the General Theory (itself a generalization of Fisher’s (1896) distinction between the real and nominal rates of interest) undercut Sraffa’s criticism. Own rates, Keynes showed, cannot deviate from each other by more than expected price appreciation plus the cost of storage and the commodity service flow, so that anticipated asset yields are equalized in intertemporal equilibrium. Thus, on Keynes’s analysis in the General Theory, the natural rate of interest is indeed well-defined. However, Keynes’s revision of Sraffa’s own-rate analysis provides only a partial rehabilitation of Hayek’s natural rate. There being no unique price level or rate of inflation in a barter system, no unique money natural rate of interest can be specified. Hayek implicitly was reasoning in terms of a constant nominal value of GDP, but barter relationships cannot identify any path for nominal GDP, let alone a constant one, as uniquely compatible with intertemporal equilibrium.

Aside from clarifying the conceptual basis of the natural-rate analysis and its relationship to Sraffa’s own-rate analysis, the paper also highlights the connection (usually overlooked but mentioned by Harald Hagemann in his 2008 article on the own rate of interest for the International Encyclopedia of the Social Sciences) between the own-rate analysis, in either its Sraffian or Keynesian versions, and Fisher’s early distinction between the real and nominal rates of interest. The conceptual identity between Fisher’s real and nominal distinction and Keynes’s own-rate analysis in the General Theory only magnifies the mystery associated with Keynes’s attack in chapter 13 of the General Theory on Fisher’s distinction between the real and the nominal rates of interest.

I also feel that the following discussion of Hayek’s role in developing the concept of intertemporal equilibrium, though tangential to the main topic of the paper, makes an important point about how to think about intertemporal equilibrium.

Perhaps the key analytical concept developed by Hayek in his early work on monetary theory and business cycles was the idea of an intertemporal equilibrium. Before Hayek, the idea of equilibrium had been reserved for a static, unchanging, state in which economic agents continue doing what they have been doing. Equilibrium is the end state in which all adjustments to a set of initial conditions have been fully worked out. Hayek attempted to generalize this narrow equilibrium concept to make it applicable to the study of economic fluctuations – business cycles – in which he was engaged. Hayek chose to formulate a generalized equilibrium concept. He did not do so, as many have done, by simply adding a steady-state rate of growth to factor supplies and technology. Nor did Hayek define equilibrium in terms of any objective or measurable magnitudes. Rather, Hayek defined equilibrium as the mutual consistency of the independent plans of individual economic agents.

The potential consistency of such plans may be conceived of even if economic magnitudes do not remain constant or grow at a constant rate. Even if the magnitudes fluctuate, equilibrium is conceivable if the fluctuations are correctly foreseen. Correct foresight is not the same as perfect foresight. Perfect foresight is necessarily correct; correct foresight is only contingently correct. All that is necessary for equilibrium is that fluctuations (as reflected in future prices) be foreseen. It is not even necessary, as Hayek (1937) pointed out, that future price changes be foreseen correctly, provided that individual agents agree in their anticipations of future prices. If all agents agree in their expectations of future prices, then the individual plans formulated on the basis of those anticipations are, at least momentarily, equilibrium plans, conditional on the realization of those expectations, because the realization of those expectations would allow the plans formulated on the basis of those expectations to be executed without need for revision. What is required for intertemporal equilibrium is therefore a contingently correct anticipation by future agents of future prices, a contingent anticipation not the result of perfect foresight, but of contingently, even fortuitously, correct foresight. The seminal statement of this concept was given by Hayek in his classic 1937 paper, and the idea was restated by J. R. Hicks (1939), with no mention of Hayek, two years later in Value and Capital.

I made the following comment in a footnote to the penultimate sentence of the quotation:

By defining correct foresight as a contingent outcome rather than as an essential property of economic agents, Hayek elegantly avoided the problems that confounded Oskar Morgenstern ([1935] 1976) in his discussion of the meaning of equilibrium.

I look forward to reading your comments.

James Grant on Irving Fisher and the Great Depression

In the past weekend edition (January 4-5, 2014) of the Wall Street Journal, James Grant, financial journalist, reviewed (“Great Minds, Failed Prophets”) Fortune Tellers by Walter A. Friedman, a new book about the first generation of economic forecasters, or business prophets. Friedman tells the stories of forecasters who became well-known and successful in the 1920s: Roger Babson, John Moody, the team of Carl J. Bullock and Warren Persons, Wesley Mitchell, and the great Irving Fisher. I haven’t read the book, but, judging from the Grant’s review, I am guessing it’s a good read.

Grant is a gifted, erudite and insightful journalist, but unfortunately his judgment is often led astray by a dogmatic attachment to Austrian business cycle theory and the gold standard, which causes him to make an absurd identification of Fisher’s views on how to stop the Great Depression with the disastrous policies of Herbert Hoover after the stock market crash.

Though undoubtedly a genius, Fisher was not immune to bad ideas, and was easily carried away by his enthusiasms. He was often right, but sometimes he was tragically wrong. His forecasting record and his scholarship made him perhaps the best known American economist in the 1920s, and a good case could be made that he was the greatest economist who ever lived, but his reputation was destroyed when, on the eve of the stock market crash, he commented “stock prices have reached what looks like a permanently high plateau.” For a year, Fisher insisted that stock prices would rebound (which they did in early 1930, recovering most of their losses), but the recovery in stock prices was short-lived, and Fisher’s public reputation never recovered.

Certainly, Fisher should have been more alert to the danger of a depression than he was. Working with a monetary theory similar to Fisher’s, both Ralph Hawtrey and Gustav Cassel foresaw the deflationary dangers associated with the restoration of the gold standard and warned against the disastrous policies of the Bank of France and the Federal Reserve in 1928-29, which led to the downturn and the crash. What Fisher thought of the warnings of Hawtrey and Cassel I don’t know, but it would be interesting and worthwhile for some researcher to go back and look for Fisher’s comments on Hawtrey and Cassel before or after the 1929 crash.

So there is no denying that Fisher got something wrong in his forecasts, but we (or least I) still don’t know exactly what his mistake was. This is where Grant’s story starts to unravel. He discusses how, under the tutelage of Wesley Mitchell, Herbert Hoover responded to the crash by “[summoning] the captains of industry to the White House.”

So when stocks crashed in 1929, Hoover, as president, summoned the captains of industry to the White House. Profits should bear the brunt of the initial adjustment to the downturn, he said. Capital-spending plans should go forward, if not be accelerated. Wages must not be cut, as they had been in the bad old days of 1920-21. The executives shook hands on it.

In the wake of this unprecedented display of federal economic activism, Wesley Mitchell, the economist, said: “While a business cycle is passing over from a phase of expansion to the phase of contraction, the president of the United States is organizing the economic forces of the country to check the threatened decline at the start, if possible. A more significant experiment in the technique of balance could not be devised than the one which is being performed before our very eyes.”

The experiment in balance ended in monumental imbalance. . . . The laissez-faire depression of 1920-21 was over and done within 18 months. The federally doctored depression of 1929-33 spanned 43 months. Hoover failed for the same reason that Babson, Moody and Fisher fell short: America’s economy is too complex to predict, much less to direct from on high.

We can stipulate that Hoover’s attempt to keep prices and wages from falling in the face of a massive deflationary shock did not aid the recovery, but neither did it cause the Depression; the deflationary shock did. The deflationary shock was the result of the failed attempt to restore the gold standard and the insane policies of the Bank of France, which might have been counteracted, but were instead reinforced, by the Federal Reserve.

Before closing, Grant turns back to Fisher, recounting, with admiration, Fisher’s continuing scholarly achievements despite the loss of his personal fortune in the crash and the collapse of his public reputation.

Though sorely beset, Fisher produced one of his best known works in 1933, the essay called “The Debt-Deflation Theory of Great Depressions,” in which he observed that plunging prices made debts unsupportable. The way out? Price stabilization, the very policy that Hoover had championed.

Grant has it totally wrong. Hoover acquiesced in, even encouraged, the deflationary policies of the Fed, and never wavered in his commitment to the gold standard. His policy of stabilizing prices and wages was largely ineffectual, because you can’t control the price level by controlling individual prices. Fisher understood the difference between controlling individual prices and controlling the price level. It is Grant, not Fisher, who resembles Hoover in failing to grasp that essential distinction.

Hawtrey’s Good and Bad Trade, Part XI: Conclusion

For many readers, I am afraid that the reaction to the title of this post will be something like: “and not a moment too soon.” When I started this series two months ago, I didn’t expect it to drag out quite this long, but I have actually enjoyed the process of reading Hawtrey’s Good and Bad Trade carefully enough to be able to explain (or at least try to explain) it to an audience of attentive readers. In the course of the past ten posts, I have actually learned a fair amount about Hawtrey that I had not known before, and a number of questions have arisen that will require further investigation and research. More stuff to keep me busy.

My previous post about financial crises and asset crashes was mainly about chapter 16, which is the final substantive discussion of Hawtrey’s business-cycle theory in the volume. Four more chapters follow, the first three are given over to questions about how government policy affects the business cycle, and finally in the last chapter a discussion about whether changes in the existing monetary system (i.e., the gold standard) might eliminate, or at least reduce, the fluctuations of the business cycle.

Chapter 17 (“Banking and Currency Legislation in Relation to the State of Trade”) actually has little to do with banking and is mainly a discussion of how the international monetary system evolved over the course of the second half of the nineteenth century from a collection of mostly bimetallic standards before 1870 to a nearly universal gold standard, the catalyst for the evolution being the 1870 decision by newly formed German Empire to adopt a gold standard and then proceeded to convert its existing coinage to a gold basis, thereby driving up the world value of gold. As a result, all the countries with bimetallic standards (usually tied to a 15.5 to 1 ratio of silver to gold) to choose between adopting the gold standard and curtailing the unlimited free coinage of silver or tolerating the inflationary effects of Gresham’s Law as overvalued and depreciating silver drove gold out of circulation.

At the end of the chapter, Hawtrey speculates about the possibility that secular inflation might have some tendency to mitigate the effects of the business cycle, comparing the period from 1870 to 1896, characterized by deflation of about 1 to 2% a year, with the period from 1896 to 1913, when inflation was roughly about 1 to 2% a year.

Experience suggests that a scarcity of new gold prolongs the periods of depression and an abundance of new gold shortens them, so that the whole period of a fluctuation is somewhat shorter in the latter circumstances than is the former. (p. 227)

Hawtrey also noted the fact that, despite unlikelihood that long-term price level movements had been correctly foreseen, the period of falling prices from 1870 to 1896 was associated with low long-term interest rates while the period from 1896 to 1913 when prices were rising was associated with high interest rates, thereby anticipating by ten years the famous empirical observation made by the British economist A. W. Gibson of the positive correlation between long-term interest rates and the price level, an observation Keynes called the Gibson’s paradox, which he expounded upon at length in his Treatise on Money.

[T]he price was affected by the experience of investments during the long gold famine when profits had been low for almost a generation, and indeed it may be regarded as the outcome of the experience. In the same way the low prices of securities at the present time are the product of the contrary experience, the great output of gold in the last twenty years having been accompanied by inflated profits. (p. 229)

Chapter 18 (“Taxation in Relation to the State of Trade”) is almost exclusively concerned not with taxation as such but with protective tariffs. The question that Hawtrey considers is whether protective tariffs can reduce the severity of the business cycle. His answer is that unless tariffs are changed during the course of a cycle, there is no reason why they should have any cyclical effect. He then asks whether an increase in the tariff would have any effect on employment during a downturn. His answer is that imposing tariffs or raising existing tariffs, by inducing a gold inflow, and thus permitting a reduction in interest rates, would tend to reduce the adverse effect of a cyclical downturn, but he stops short of advocating such a policy, because of the other adverse effects of the protective tariff, both on the country imposing the tariff and on its neighbors.

Chapter 19 (“Public Finance in Relation to the State of Trade”) is mainly concerned with the effects of the requirements of the government for banking services in making payments to and accepting payments from the public.

Finally, Chapter 20 (“Can Fluctuations Be Prevented?”) addresses a number of proposals for mitigating the effects of the business cycle by means of policy or changes institutional reform. Hawtrey devotes an extended discussion to Irving Fisher’s proposal for a compensated dollar. Hawtrey is sympathetic, in principle, to the proposal, but expressed doubts about its practicality, a) because it did not seem in 1913 that replacing the gold standard was politically possible, b) because Hawtrey doubted that a satisfactory price index could be constructed, and c) because the plan would, at best, only mitigate, not eliminate, cyclical fluctuations.

Hawtrey next turns to the question whether government spending could be timed to coincide with business cycle downturns so that it would offset the reduction in private spending, thereby preventing the overall demand for labor from falling as much as it otherwise would during the downturn. Hawtrey emphatically rejects this idea because any spending by the government on projects would simply displace an equal amount of private spending, leaving total expenditure unchanged.

The underlying principle of this proposal is that the Government should add to the effective demand for labour at the time when the effective private demand of private traders falls off. But [the proposal] appears to have overlooked the fact that the Government by the very fact of borrowing for this expenditure is withdrawing from the investment market savings which would otherwise be applied to the creation of capital. (p. 260)

Thus, already in 1913, Hawtrey formulated the argument later advanced in his famous 1925 paper on “Public Expenditure and the Demand for Labour,” an argument which eventually came to be known as the Treasury view. The Treasury view has been widely condemned, and, indeed, it did overlook the possibility that government expenditure might induce private funds that were being hoarded as cash to be released for spending on investment. This tendency, implied by the interest-elasticity of the demand for money, would prevent government spending completely displacing private spending, as the Treasury view asserted. But as I have observed previously, despite the logical gap in Hawtrey’s argument, the mistake was not as bad as it is reputed to be, because, according to Hawtrey, the decline in private spending was attributable to a high rate of interest, so that the remedy for unemployment is to be found in a reduction in the rate of interest rather than an increase in government spending.

And with that, I think I will give Good and Bad Trade and myself a rest.

Keynes on the Fisher Equation and Real Interest Rates

Almost two months ago, I wrote a post (“Who Sets the Real Rate of Interest?”) about the Fisher equation, questioning the idea that the Fed can, at will, reduce the real rate of interest by printing money, an idea espoused by a lot of people who also deny that the Fed has the power to reduce the rate of unemployment by printing money. A few weeks later, I wrote another post (“On a Difficult Passage in the General Theory“) in which I pointed out the inconsistency between Keynes’s attack on the Fisher equation in chapter 11 of the General Theory and his analysis in chapter 17 of the liquidity premium and the conditions for asset-market equilibrium, an analysis that led Keynes to write down what is actually a generalized version of the Fisher equation. In both of those posts I promised a future post about how to understand the dynamic implications of the Fisher equation and the relationship between Fisher equation and the Keynesian analysis. This post is an attempt to make good on those promises.

As I observed in my earlier post, the Fisher equation is best understood as a property of equilibrium. If the Fisher equation does not hold, then it is reasonable to attribute the failure to some sort of disequilibrium. The most obvious, but not the only, source of disequilibrium is incorrectly expected inflation. Other sources of disequilibrium could be a general economic disorder, the entire economic system being (seriously) out of equilibrium, implying that the real rate of interest is somehow different from the “equilibrium” rate, or, as Milton Friedman might put it, that the real rate is different from the rate that would be ground out by the system of Walrasian (or Casselian or Paretian or Fisherian) equations.

Still a third possibility is that there is more than one equilibrium (i.e., more than one solution to whichever system of equations we are trying to solve). If so, as an economy moves from one equilibrium path to another through time, the nominal (and hence the real) rate of that economy could be changing independently of changes in expected inflation, thereby nullifying the empirical relationship implied (under the assumption of a unique equilibrium) by the Fisher equation.

Now in the canonical Fisherian theory of interest, there is, at any moment of time, a unique equilibrium rate of interest (actually a unique structure of equilibrium rates for all possible combinations of time periods), increasing thrift tending to reduce rates and increasing productivity of capital tending to raise them. While uniqueness of the interest rate cannot easily be derived outside a one-commodity model, the assumption did not seem all that implausible in the context of the canonical Fisherian model with a given technology and given endowments of present and future resources. In the real world, however, the future is unknown, so the future exists now only in our imagination, which means that, fundamentally, the determination of real interest rates cannot be independent of our expectations of the future. There is no unique set of expectations that is consistent with “fundamentals.” Fundamentals and expectations interact to create the future; expectations can be self-fulfilling. One of the reasons why expectations can be self-fulfilling is that often it is the case that individual expectations can only be realized if they are congruent with the expectations of others; expectations are subject to network effects. That was the valid insight in Keynes’s “beauty contest” theory of the stock market in chapter 12 of the GT.

There simply is no reason why there would be only one possible equilibrium time path. Actually, the idea that there is just one possible equilibrium time path seems incredible to me. It seems infinitely more likely that there are many potential equilibrium time paths, each path conditional on a corresponding set of individual expectations. To be sure, not all expectations can be realized. Expectations that can’t be realized produce bubbles. But just because expectations are not realized doesn’t mean that the observed price paths were bubbles; as long as it was possible, under conditions that could possibly have obtained, that the expectations could have been realized, the observed price paths were not bubbles.

Keynes was not the first economist to attribute economic fluctuations to shifts in expectations; J. S. Mill, Stanley Jevons, and A. C. Pigou, among others, emphasized recurrent waves of optimism and pessimism as the key source of cyclical fluctuations. The concept of the marginal efficiency of capital was used by Keynes to show the dependence of the desired capital stock, and hence the amount of investment, on the state of entrepreneurial expectations, but Keynes, just before criticizing the Fisher equation, explicitly identified the MEC with the Fisherian concept of “the rate of return over cost.” At a formal level, at any rate, Keynes was not attacking the Fisherian theory of interest.

So what I want to suggest is that, in attacking the Fisher equation, Keynes was really questioning the idea that a change in inflation expectations operates strictly on the nominal rate of interest without affecting the real rate. In a world in which there is a unique equilibrium real rate, and in which the world is moving along a time-path in the neighborhood of that equilibrium, a change in inflation expectations may operate strictly on the nominal rate and leave the real rate unchanged. In chapter 11, Keynes tried to argue the opposite: that the entire adjustment to a change in expected inflation is concentrated on real rate with the nominal rate unchanged. This idea seems completely unfounded. However, if the equilibrium real rate is not unique, why assume, as the standard renditions of the Fisher equation usually do, that a change in expected inflation affects only the nominal rate? Indeed, even if there is a unique real rate – remember that “unique real rate” in this context refers to a unique yield curve – the assumption that the real rate is invariant with respect to expected inflation may not be true in an appropriate comparative-statics exercise, such as the 1950s-1960s literature on inflation and growth, which recognized the possibility that inflation could induce a shift from holding cash to holding real assets, thereby increasing the rate of capital accumulation and growth, and, consequently, reducing the equilibrium real rate. That literature was flawed, or at least incomplete, in its analysis of inflation, but it was motivated by a valid insight.

In chapter 17, after deriving his generalized version of the Fisher equation, Keynes came back to this point when explaining why he had now abandoned the Wicksellian natural-rate analysis of the Treatise on Money. The natural-rate analysis, Keynes pointed out, presumes the existence of a unique natural rate of interest, but having come to believe that there could be an equilibrium associated with any level of employment, Keynes now concluded that there is actually a natural rate of interest corresponding to each level of employment. What Keynes failed to do in this discussion was to specify the relationship between natural rates of interest and levels of employment, leaving a major gap in his theoretical structure. Had he specified the relationship, we would have an explicit Keynesian IS curve, which might well differ from the downward-sloping Hicksian IS curve. As Earl Thompson, and perhaps others, pointed out about 40 years ago, the Hicksian IS curve is inconsistent with the standard neoclassical theory of production, which Keynes seems (provisionally at least) to have accepted when arguing that, with a given technology and capital stock, increased employment is possible only at a reduced real wage.

But if the Keynesian IS curve is upward-sloping, then Keynes’s criticism of the Fisher equation in chapter 11 is even harder to make sense of than it seems at first sight, because an increase in expected inflation would tend to raise, not (as Keynes implicitly assumed) reduce, the real rate of interest. In other words, for an economy operating at less than full employment, with all expectations except the rate of expected inflation held constant, an increase in the expected rate of inflation, by raising the marginal efficiency of capital, and thereby increasing the expected return on investment, ought to be associated with increased nominal and real rates of interest. If we further assume that entrepreneurial expectations are positively related to the state of the economy, then the positive correlation between inflation expectations and real interest rates would be enhanced. On this interpretation, Keynes’s criticism of the Fisher equation in chapter 11 seems indefensible.

That is one way of looking at the relationship between inflation expectations and the real rate of interest. But there is also another way.

The Fisher equation tells us that, in equilibrium, the nominal rate equals the sum of the prospective real rate and the expected rate of inflation. Usually that’s not a problem, because the prospective real rate tends to be positive, and inflation (at least since about 1938) is almost always positive. That’s the normal case. But there’s also an abnormal (even pathological) case, where the sum of expected inflation and the prospective real rate of interest is less than zero. We know right away that such a situation is abnormal, because it is incompatible with equilibrium. Who would lend money at a negative rate when it’s possible to hold the money and get a zero return? The nominal rate of interest can’t be negative. So if the sum of the prospective real rate (the expected yield on real capital) and the expected inflation rate (the negative of the expected yield on money with a zero nominal interest rate) is negative, then the return to holding money exceeds the yield on real capital, and the Fisher equation breaks down.

In other words, if r + dP/dt < 0, where r is the real rate of interest and dP/dt is the expected rate of inflation, then r < -dP/dt. But since i, the nominal rate of interest, cannot be less than zero, the Fisher equation does not hold, and must be replaced by the Fisher inequality

i > r + dP/dt.

If the Fisher equation can’t be satisfied, all hell breaks loose. Asset prices start crashing as asset owners try to unload their real assets for cash. (Note that I have not specified the time period over which the sum of expected inflation and the prospective yield on real capital are negative. Presumably the duration of that period is not indefinitely long. If it were, the system might implode.)

That’s what was happening in the autumn of 2008, when short-term inflation expectations turned negative in a contracting economy in which the short-term prospects for investment were really lousy and getting worse. The prices of real assets had to fall enough to raise the prospective yield on real assets above the expected yield from holding cash. However, falling asset prices don’t necessary restore equilibrium, because, once a panic starts it can become contagious, with falling asset prices reinforcing the expectation that asset prices will fall, depressing the prospective yield on real capital, so that, rather than bottoming out, the downward spiral feeds on itself.

Thus, for an economy at the zero lower bound, with the expected yield from holding money greater than the prospective yield on real capital, a crash in asset prices may not stabilize itself. If so, something else has to happen to stop the crash: the expected yield from holding money must be forced below the prospective yield on real capital. With the prospective yield on real capital already negative, forcing down the expected yield on money below the prospective yield on capital requires raising expected inflation above the absolute value of the prospective yield on real capital. Thus, if the prospective yield on real capital is -5%, then, to stop the crash, expected inflation would have to be raised to over 5%.

But there is a further practical problem. At the zero lower bound, not only is the prospective real rate not observable, it can’t even be inferred from the Fisher equation, the Fisher equation having become an inequality. All that can be said is that r < -dP/dt.

So, at the zero lower bound, achieving a recovery requires raising expected inflation. But how does raising expected inflation affect the nominal rate of interest? If r + dP/dt < 0, then increasing expected inflation will not increase the nominal rate of interest unless dP/dt increases enough to make r + dP/dt greater than zero. That’s what Keynes seemed to be saying in chapter 11, raising expected inflation won’t affect the nominal rate of interest, just the real rate. So Keynes’s criticism of the Fisher equation seems valid only in the pathological case when the Fisher equation is replaced by the Fisher inequality.

In my paper “The Fisher Effect Under Deflationary Expectations,” I found that a strongly positive correlation between inflation expectations (approximated by the breakeven TIPS spread on 10-year Treasuries) and asset prices (approximated by S&P 500) over the time period from spring 2008 through the end of 2010, while finding no such correlation over the period from 2003 to 2008. (Extending the data set through 2012 showed the relationship persisted through 2012 but may have broken down in 2013.) This empirical finding seems consistent with the notion that there has been something pathological about the period since 2008. Perhaps one way to think about the nature of the pathology is that the Fisher equation has been replaced by the Fisher inequality, a world in which changes in inflation expectations are reflected in changes in real interest rates instead of changes in nominal rates, the most peculiar kind of world described by Keynes in chapter 11 of the General Theory.

On a Difficult Passage in the General Theory

Keynes’s General Theory is not, in my estimation, an easy read. The terminology is often unfamiliar, and, so even after learning one of his definitions, I have trouble remembering what the term means the next time it’s used.. And his prose style, though powerful and very impressive, is not always clear, so you can spend a long time reading and rereading a sentence or a paragraph before you can figure out exactly what he is trying to say. I am not trying to be critical, just to point out that the General Theory is a very challenging book to read, which is one, but not the only, reason why it is subject to a lot of conflicting interpretations. And, as Harry Johnson once pointed out, there is an optimum level of difficulty for a book with revolutionary aspirations. If it’s too simple, it won’t be taken seriously. And if it’s too hard, no one will understand it. Optimally, a revolutionary book should be hard enough so that younger readers will be able to figure it out, and too difficult for the older guys to understand or to make the investment in effort to understand.

In this post, which is, in a certain sense, a follow-up to an earlier post about what, or who, determines the real rate of interest, I want to consider an especially perplexing passage in the General Theory about the Fisher equation. It is perplexing taken in isolation, and it is even more perplexing when compared to other passages in both the General Theory itself and in Keynes’s other writings. Here’s the passage that I am interested in.

The expectation of a fall in the value of money stimulates investment, and hence employment generally, because it raises the schedule of the marginal efficiency of capital, i.e., the investment demand-schedule; and the expectation of a rise in the value of money is depressing, because it lowers the schedule of the marginal efficiency of capital. This is the truth which lies behind Professor Irving Fisher’s theory of what he originally called “Appreciation and Interest” – the distinction between the money rate of interest and the real rate of interest where the latter is equal to the former after correction for changes in the value of money. It is difficult to make sense of this theory as stated, because it is not clear whether the change in the value of money is or is not assumed to be foreseen. There is no escape from the dilemma that, if it is not foreseen, there will be no effect on current affairs; whilst, if it is foreseen, the prices of exiting goods will be forthwith so adjusted that the advantages of holding money and of holding goods are again equalized, and it will be too late for holders of money to gain or to suffer a change in the rate of interest which will offset the prospective change during the period of the loan in the value of the money lent. For the dilemma is not successfully escaped by Professor Pigou’s expedient of supposing that the prospective change in the value of money is foreseen by one set of people but not foreseen by another. (p. 142)

The statement is problematic on just about every level, and one hardly knows where to begin in discussing it. But just for starters, it is amazing that Keynes seems (or, for rhetorical purposes, pretends) to be in doubt whether Fisher is talking about anticipated or unanticipated inflation, because Fisher himself explicitly distinguished between anticipated and unanticipated inflation, and Keynes could hardly have been unaware that Fisher was explicitly speaking about anticipated inflation. So the implication that the Fisher equation involves some confusion on Fisher’s part between anticipated and unanticipated inflation was both unwarranted and unseemly.

What’s even more puzzling is that in his Tract on Monetary Reform, Keynes expounded the covered interest arbitrage principle that the nominal-interest-rate-differential between two currencies corresponds to the difference between the spot and forward rates, which is simply an extension of Fisher’s uncovered interest arbitrage condition (alluded to by Keynes in referring to “Appreciation and Interest”). So when Keynes found Fisher’s distinction between the nominal and real rates of interest to be incoherent, did he really mean to exempt his own covered interest arbitrage condition from the charge?

But it gets worse, because if we flip some pages from chapter 11, where the above quotation is found, to chapter 17, we see on page 224, the following passage in which Keynes extends the idea of a commodity or “own rate of interest” to different currencies.

It may be added that, just as there are differing commodity-rates of interest at any time, so also exchange dealers are familiar with the fact that the rate of interest is not even the same in terms of two different moneys, e.g. sterling and dollars. For here also the difference between the “spot” and “future” contracts for a foreign money in terms of sterling are not, as a rule, the same for different foreign moneys. . . .

If no change is expected in the relative value of two alternative standards, then the marginal efficiency of a capital-asset will be the same in whichever of the two standards it is measured, since the numerator and denominator of the fraction which leads up to the marginal efficiency will be changed in the same proportion. If, however, one of the alternative standards is expected to change in value in terms of the other, the marginal efficiencies of capital-assets will be changed by the same percentage, according to which standard they are measured in. To illustrate this let us take the simplest case where wheat, one of the alternative standards, is expected to appreciate at a steady rate of a percent per annum in terms of money; the marginal efficiency of an asset, which is x percent in terms of money, will then be x – a percent in terms of wheat. Since the marginal efficiencies of all capital assets will be altered by the same amount, it follows that their order of magnitude will be the same irrespective of the standard which is selected.

So Keynes in chapter 17 explicitly allows for the nominal rate of interest to be adjusted to reflect changes in the expected value of the asset (whether a money or a commodity) in terms of which the interest rate is being calculated. Mr. Keynes, please meet Mr. Keynes.

I think that one source of Keynes’s confusion in attacking the Fisher equation was his attempt to force the analysis of a change in inflation expectations, clearly a disequilibrium, into an equilibrium framework. In other words, Keynes is trying to analyze what happens when there has been a change in inflation expectations as if the change had been foreseen. But any change in inflation expectations, by definition, cannot have been foreseen, because to say that an expectation has changed means that the expectation is different from what it was before. Perhaps that is why Keynes tied himself into knots trying to figure out whether Fisher was talking about a change in the value of money that was foreseen or not foreseen. In any equilibrium, the change in the value of money is foreseen, but in the transition from one equilibrium to another, the change is not foreseen. When an unforeseen change occurs in expected inflation, leading to a once-and-for-all change in the value of money relative to other assets, the new equilibrium will be reestablished given the new value of money relative to other assets.

But I think that something else is also going on here, which is that Keynes was implicitly assuming that a change in inflation expectations would alter the real rate of interest. This is a point that Keynes makes in the paragraph following the one I quoted above.

The mistake lies in supposing that it is the rate of interest on which prospective changes in the value of money will directly react, instead of the marginal efficiency of a given stock of capital. The prices of existing assets will always adjust themselves to changes in expectation concerning the prospective value of money. The significance of such changes in expectation lies in their effect on the readiness to produce new assets through their reaction on the marginal efficiency of capital. The stimulating effect of the expectation of higher prices is due, not to its raising the rate of interest (that would be a paradoxical way of stimulating output – insofar as the rate of interest rises, the stimulating effect is to that extent offset) but to its raising the marginal efficiency of a given stock of capital. If the rate of interest were to rise pari passu with the marginal efficiency of capital, there would be no stimulating effect from the expectation of rising prices. For the stimulating effect depends on the marginal efficiency of capital rising relativevly to the rate of interest. Indeed Professor Fisher’s theory could best be rewritten in terms of a “real rate of interest” defined as being the rate of interest which would have to rule, consequently on change in the state of expectation as to the future value of money, in order that this change should have no effect on current output. (pp. 142-43)

Keynes’s mistake lies in supposing that an increase in inflation expectations could not have a stimulating effect except as it raises the marginal efficiency of capital relative to the rate of interest. However, the increase in the value of real assets relative to money will increase the incentive to produce new assets. It is the rise in the value of existing assets relative to money that raises the marginal efficiency of those assets, creating an incentive to produce new assets even if the nominal interest rate were to rise by as much as the rise in expected inflation.

Keynes comes back to this point at the end of chapter 17, making it more forcefully than he did the first time.

In my Treatise on Money I defined what purported to be a unique rate of interest, which I called the natural rate of interest – namely, the rate of interest which, in the terminology of my Treatise, preserved equality between the rate of saving (as there defined) and the rate of investment. I believed this to be a development and clarification of of Wicksell’s “natural rate of interest,” which was, according to him, the rate which would preserve the stability of some, not quite clearly specified, price-level.

I had, however, overlooked the fact that in any given society there is, on this definition, a different natural rate for each hypothetical level of employment. And, similarly, for every rate of interest there is a level of employment for which that rate is the “natural” rate, in the sense that the system will be in equilibrium with that rate of interest and that level of employment. Thus, it was a mistake to speak of the natural rate of interest or to suggest that the above definition would yield a unique value for the rate of interest irrespective of the level of employment. . . .

If there is any such rate of interest, which is unique and significant, it must be the rate which we might term the neutral rate of interest, namely, the natural rate in the above sense which is consistent with full employment, given the other parameters of the system; though this rate might be better described, perhaps, as the optimum rate. (pp. 242-43)

So what Keynes is saying, I think, is this. Consider an economy with a given fixed marginal efficiency of capital (MEC) schedule. There is some interest rate that will induce sufficient investment expenditure to generate enough spending to generate full employment. That interest rate Keynes calls the “neutral” rate of interest. If the nominal rate of interest is more than the neutral rate, the amount of investment will be less than the amount necessary to generate full employment. In such a situation an expectation that the price level will rise will shift up the MEC schedule by the amount of the expected increase in inflation, thereby generating additional investment spending. However, because the MEC schedule is downward-sloping, the upward shift in the MEC schedule that induces increased investment spending will correspond to an increase in the rate of interest that is less than the increase in expected inflation, the upward shift in the MEC schedule being partially offset by the downward movement along the MEC schedule. In other words, the increase in expected inflation raises the nominal rate of interest by less than increase in expected inflation by inducing additional investment that is undertaken only because the real rate of interest has fallen.

However, for an economy already operating at full employment, an increase in expected inflation would not increase employment, so whether there was any effect on the real rate of interest would depend on the extent to which there was a shift from holding money to holding real capital assets in order to avoid the inflation tax.

Before closing, I will just make two side comments. First, my interpretation of Keynes’s take on the Fisher equation is similar to that of Allin Cottrell in his 1994 paper “Keynes and the Keynesians on the Fisher Effect.” Second, I would point out that the Keynesian analysis violates the standard neoclassical assumption that, in a two-factor production function, the factors are complementary, which implies that an increase in employment raises the MEC schedule. The IS curve is not downward-sloping, but upward sloping. This is point, as I have explained previously (here and here), was made a long time ago by Earl Thompson, and it has been made recently by Nick Rowe and Miles Kimball.

I hope in a future post to work out in more detail the relationship between the Keynesian and the Fisherian analyses of real and nominal interest rates.

Who Sets the Real Rate of Interest?

Understanding economics requires, among other things, understanding the distinction between real and nominal variables. Confusion between real and nominal variables is pervasive, constantly presenting barriers to clear thinking, and snares and delusions for the mentally lazy. In this post, I want to talk about the distinction between the real rate of interest and the nominal rate of interest. That distinction has been recognized for at least a couple of centuries, Henry Thornton having mentioned it early in the nineteenth century. But the importance of the distinction wasn’t really fully understood until Irving Fisher made the distinction between the real and nominal rates of interest a key element of his theory of interest and his theory of money, expressing the relationship in algebraic form — what we now call the Fisher equation. Notation varies, but the Fisher equation can be written more or less as follows:

i = r + dP/dt,

where i is the nominal rate, r is the real rate, and dP/dt is the rate of inflation. It is important to bear in mind that the Fisher equation can be understood in two very different ways. It can either represent an ex ante relationship, with dP/dt referring to expected inflation, or it can represent an ex post relationship, with dP/dt referring to actual inflation.

What I want to discuss in this post is the tacit assumption that usually underlies our understanding, and our application, of the ex ante version of the Fisher equation. There are three distinct variables in the Fisher equation: the real and the nominal rates of interest and the rate of inflation. If we think of the Fisher equation as an ex post relationship, it holds identically, because the unobservable ex post real rate is defined as the difference between the nominal rate and the inflation rate. The ex post, or the realized, real rate has no independent existence; it is merely a semantic convention. But if we consider the more interesting interpretation of the Fisher equation as an ex ante relationship, the real interest rate, though still unobservable, is not just a semantic convention. It becomes the theoretically fundamental interest rate of capital theory — the market rate of intertemporal exchange, reflecting, as Fisher masterfully explained in his canonical renderings of the theory of capital and interest, the “fundamental” forces of time preference and the productivity of capital. Because it is determined by economic “fundamentals,” economists of a certain mindset naturally assume that the real interest rate is independent of monetary forces, except insofar as monetary factors are incorporated in inflation expectations. But if money is neutral, at least in the long run, then the real rate has to be independent of monetary factors, at least in the long run. So in most expositions of the Fisher equation, it is tacitly assumed that the real rate can be treated as a parameter determined, outside the model, by the “fundamentals.” With r determined exogenously, fluctuations in i are correlated with, and reflect, changes in expected inflation.

Now there’s an obvious problem with the Fisher equation, which is that in many, if not most, monetary models, going back to Thornton and Wicksell in the nineteenth century, and to Hawtrey and Keynes in the twentieth, and in today’s modern New Keynesian models, it is precisely by way of changes in its lending rate to the banking system that the central bank controls the rate of inflation. And in this framework, the nominal interest rate is negatively correlated with inflation, not positively correlated, as implied by the usual understanding of the Fisher equation. Raising the nominal interest rate reduces inflation, and reducing the nominal interest rate raises inflation. The conventional resolution of this anomaly is that the change in the nominal interest rate is just temporary, so that, after the economy adjusts to the policy of the central bank, the nominal interest rate also adjusts to a level consistent with the exogenous real rate and to the rate of inflation implied by the policy of the central bank. The Fisher equation is thus an equilibrium relationship, while central-bank policy operates by creating a short-term disequilibrium. But the short-term disequilibrium imposed by the central bank cannot be sustained, because the economy inevitably begins an adjustment process that restores the equilibrium real interest rate, a rate determined by fundamental forces that eventually override any nominal interest rate set by the central bank if that rate is inconsistent with the equilibrium real interest rate and the expected rate of inflation.

It was just this analogy between the powerlessness of the central bank to hold the nominal interest rate below the sum of the exogenously determined equilibrium real rate and the expected rate of inflation that led Milton Friedman to the idea of a “natural rate of unemployment” when he argued that monetary policy could not keep the unemployment rate below the “natural rate ground out by the Walrasian system of general equilibrium equations.” Having been used by Wicksell as a synonym for the Fisherian equilibrium real rate, the term “natural rate” was undoubtedly adopted by Friedman, because monetarily induced deviations between the actual rate of unemployment and the natural rate of unemployment set in motion an adjustment process that restores unemployment to its “natural” level, just as any deviation between the nominal interest rate and the sum of the equilibrium real rate and expected inflation triggers an adjustment process that restores equality between the nominal rate and the sum of the equilibrium real rate and expected inflation.

So, if the ability of the central bank to use its power over the nominal rate to control the real rate of interest is as limited as the conventional interpretation of the Fisher equation suggests, here’s my question: When critics of monetary stimulus accuse the Fed of rigging interest rates, using the Fed’s power to keep interest rates “artificially low,” taking bread out of the mouths of widows, orphans and millionaires, what exactly are they talking about? The Fed has no legal power to set interest rates; it can only announce what interest rate it will lend at, and it can buy and sell assets in the market. It has an advantage because it can create the money with which to buy assets. But if you believe that the Fed cannot reduce the rate of unemployment below the “natural rate of unemployment” by printing money, why would you believe that the Fed can reduce the real rate of interest below the “natural rate of interest” by printing money? Martin Feldstein and the Wall Street Journal believe that the Fed is unable to do one, but perfectly able to do the other. Sorry, but I just don’t get it.

Look at the accompanying chart. It tracks the three variables in the Fisher equation (the nominal interest rate, the real interest rate, and expected inflation) from October 1, 2007 to July 2, 2013. To measure the nominal interest rate, I use the yield on 10-year Treasury bonds; to measure the real interest rate, I use the yield on 10-year TIPS; to measure expected inflation, I use the 10-year breakeven TIPS spread. The yield on the 10-year TIPS is an imperfect measure of the real rate, and the 10-year TIPS spread is an imperfect measure of inflation expectations, especially during financial crises, when the rates on TIPS are distorted by illiquidity in the TIPS market. Those aren’t the only problems with identifying the TIPS yield with the real rate and the TIPS spread with inflation expectations, but those variables usually do provide a decent approximation of what is happening to real rates and to inflation expectations over time.


Before getting to the main point, I want to make a couple of preliminary observations about the behavior of the real rate over time. First, notice that the real rate declined steadily, with a few small blips, from October 2007 to March 2008, when the Fed was reducing the Fed Funds target rate from 4.75 to 3% as the economy was sliding into a recession that officially began in December 2007. The Fed reduced the Fed Funds target to 2% at the end of April, but real interest rates had already started climbing in early March, so the failure of the FOMC to reduce the Fed Funds target again till October 2008, three weeks after the onset of the financial crisis, clearly meant that there was at least a passive tightening of monetary policy throughout the second and third quarters, helping create the conditions that precipitated the crisis in September. The rapid reduction in the Fed Funds target from 2% in October to 0.25% in December 2008 brought real interest rates down, but, despite the low Fed Funds rate, a lack of liquidity caused a severe tightening of monetary conditions in early 2009, forcing real interest rates to rise sharply until the Fed announced its first QE program in March 2009.

I won’t go into more detail about ups and downs in the real rate since March 2009. Let’s just focus on the overall trend. From that time forward, what we see is a steady decline in real interest rates from over 2% at the start of the initial QE program till real rates bottomed out in early 2012 at just over -1%. So, over a period of three years, there was a steady 3% decline in real interest rates. This was no temporary phenomenon; it was a sustained trend. I have yet to hear anyone explain how the Fed could have single-handedly produced a steady downward trend in real interest rates by way of monetary expansion over a period of three years. To claim that decline in real interest rates was caused by monetary expansion on the part of the Fed flatly contradicts everything that we think we know about the determination of real interest rates. Maybe what we think we know is all wrong. But if it is, people who blame the Fed for a three-year decline in real interest rates that few reputable economists – and certainly no economists that Fed critics pay any attention to — ever thought was achievable by monetary policy ought to provide an explanation for how the Fed suddenly got new and unimagined powers to determine real interest rates. Until they come forward with such an explanation, Fed critics have a major credibility problem.

So please – pleaseWall Street Journal editorial page, Martin Feldstein, John Taylor, et al., enlighten us. We’re waiting.

PS Of course, there is a perfectly obvious explanation for the three-year long decline in real interest rates, but not one very attractive to critics of QE. Either the equilibrium real interest rate has been falling since 2009, or the equilibrium real interest rate fell before 2009, but nominal rates adjusted slowly to the reduced real rate. The real interest rate might have adjusted more rapidly to the reduced equilibrium rate, but that would have required expected inflation to have risen. What that means is that sometimes it is the real interest rate, not, as is usually assumed, the nominal rate, that adjusts to the expected rate of inflation. My next post will discuss that alternative understanding of the implicit dynamics of the Fisher equation.

That Oh So Elusive Natural Rate of Interest

Last week, I did a short post linking to the new draft of my paper with Paul Zimmerman about the Sraffa-Hayek exchange on the natural rate of interest. In the paper, we attempt to assess Sraffa’s criticism in his 1932 review of Prices and Production of Hayek’s use of the idea of a natural rate of interest as well as Hayek’s response, or, perhaps, his lack of response, to Sraffa’s criticism. The issues raised by Sraffa are devilishly tricky, especially because he introduced the unfamiliar terminology of own-rates of interest, later adopted Keynes in chapter 17 of the General Theory in order to express his criticism. The consensus about this debate is that Sraffa got the best of Hayek in this exchange – the natural rate of interest was just one of the issues Sraffa raised, and, in the process, he took Hayek down a peg or two after the startling success that Hayek enjoyed upon his arrival in England, and publication of Prices and Production. In a comment to my post, Greg Ransom questions this conventional version of the exchange, but that’s my story and I’m sticking to it.

What Paul and I do in the paper is to try to understand Sraffa’s criticism of Hayek. It seems to us that the stridency of Sraffa’s attack on Hayek suggests that Sraffa was arguing that Hayek’s conception of a natural rate of interest was somehow incoherent in a barter economy in which there is growth and investment and, thus, changes in relative prices over time, implying that commodity own rates of interest would have differ. If, in a barter economy with growth and savings and investment, there are many own-rates, Sraffa seemed to be saying, it is impossible to identify any one of them as the natural rate of interest. In a later account of the exchange between Sraffa and Hayek, Ludwig Lachmann, a pupil of Hayek, pointed out that, even if there are many own rates in a barter economy, the own rates must, in an intertemporal equilibrium, stand in a unique relationship to each other: the expected net return from holding any asset cannot differ from the expected net return on holding any other asset. That is a condition of equilibrium. If so, it is possible, at least conceptually, to infer a unique real interest rate. That unique real interest rate could be identified with Hayek’s natural rate of interest.

In fact, as we point out in our paper, Irving Fisher in his classic Appreciation and Interest (1896) had demonstrated precisely this point, theoretically extracting the real rate from the different nominal rates of interest corresponding to loans contracted in terms of different assets with different expected rates of price appreciation. Thus, Sraffa did not demonstrate that there was no natural rate of interest. There is a unique real rate of interest in intertemporal equilibrium which corresponds to the Hayekian natural rate. However, what Sraffa could have demonstrated — though had he done so, he would still have been 35 years behind Irving Fisher – is that the unique real rate is consistent with an infinite number of nominal rates provided that those nominal rates reflected corresponding anticipated rate of price appreciation. But, instead, Sraffa argued that there is no unique real rate in intertemporal equilibrium. That was a mistake.

Another interesting (at least to us) point in our paper is that Keynes who, as editor of the Economic Journal, asked Sraffa to review Prices and Production, borrowed Sraffa’s own-rate terminology in chapter 17 of the General Theory, but, instead of following Sraffa’s analysis and arguing that there is no natural rate of interest, Keynes proceeded to derive, using (without acknowledgment) a generalized version of Fisher’s argument of 1896, a unique relationship between commodity own rates, adjusted for expected price changes, and net service yields, such that the expected net returns on all assets would be equalized. From this, Keynes did not conclude, as had Sraffa, that there is no natural rate of interest. Rather, he made a very different argument: that the natural rate of interest is a useless concept, because there are many natural rates each corresponding to a different the level of income and employment, a consideration that Hayek, and presumably Fisher, had avoided by assuming full intertemporal equilibrium. But Keynes never disputed that for any given level of income and employment, there would be a unique real rate to which all commodity own rates had to correspond. Thus, Keynes turned Sraffa’s analysis on its head. And the final point of interest is that even though Keynes, in chapter 17, presented essentially the same analysis of own rates, though in more general terms, that Fisher had presented 40 years earlier, Keynes in chapter 13 explicitly rejected Fisher’s distinction between the real and nominal rates of interest. Go figure.

Bob Murphy wrote a nice paper on the Sraffa-Hayek debate, which I have referred to before on this blog. However, I disagree with him that Sraffa’s criticism of Hayek was correct. In a post earlier this week, he infers, from our statement that, as long as price expectations are correct, any nominal rate is consistent with the unique real natural rate, that we must agree with him that Sraffa was right and Hayek was wrong about the natural rate. I think that Bob is in error on the pure theory here. There is a unique real natural rate in intertemporal equilibrium, and, in principle, the monetary authority could set a money rate equal to that real rate, provided that that nominal rate was consistent with the price expectations held by the public. However, intertemporal equilibrium could be achieved by any nominal interest rate selected by the monetary authority, again provided that the nominal rate chosen was consistent with the price expectations held by the public. In practice, either formulation is very damaging to Hayek’s policy criterion of setting the nominal interest rate equal to the real natural rate. But contrary to Sraffa’s charge, the policy criterion is not incoherent. It is just unworkable, as Hayek formulated it, and, on Hayek’s own theory, the criterion is unnecessary to avoid distorting malinvestments.

My Paper (co-authored with Paul Zimmerman) on Hayek and Sraffa

I have just uploaded to the SSRN website a new draft of the paper (co-authored with Paul Zimmerman) on Hayek and Sraffa and the natural rate of interest, presented last June at the History of Economics Society conference at Brock University. The paper evolved from an early post on this blog in September 2011. I also wrote about the Hayek-Sraffa controversy in a post in June 2012 just after the HES conference.

One interesting wrinkle that occurred to me just as I was making revisions in the paper this week is that Keynes’s treatment of own rates in chapter 17 of the General Theory, which was in an important sense inspired by Sraffa, but, in my view, came to a very different conclusion from Sraffa’s, was actually nothing more than a generalization of Irving Fisher’s analysis of the real and nominal rates of interest, first presented in Fisher’s 1896 book Appreciation and Interest. In his Tract on Monetary Reform, Keynes extended Fisher’s analysis into his theory of covered interest rate arbitrage. What is really surprising is that, despite his reliance on Fisher’s analysis in the Tract and also in the Treatise on Money, Keynes sharply criticized Fisher’s analysis of the nominal and real rates of interest in chapter 13 of the General Theory. (I discussed that difficult passage in the General Theory in this post).  That is certainly surprising. But what is astonishing to me is that, after trashing Fisher in chapter 13 of the GT, Keynes goes back to Fisher in chapter 17, giving a generalized restatement of Fisher’s analysis in his discussion of own rates. Am I the first person to have noticed Keynes’s schizophrenic treatment of Fisher in the General Theory?

PS: My revered teacher, the great Armen Alchian passed away yesterday at the age of 98. There have been many tributes to him, such as this one by David Henderson, also a student of Alchian’s, in the Wall Street Journal. I have written about Alchian in the past (here, here, here, here, and here), and I hope to write about Alchian again in the near future. There was none like him; he will be missed terribly.

Falling Real Interest Rates, Winner-Take-All Markets, and Lance Armstrong

In my previous post, I suggested that real interest rates are largely determined by expectations, entrepreneurial expectations of profit and household expectations of future income. Increased entrepreneurial optimism implies that entrepreneurs are revising upwards the anticipated net cash flows from the current stock of capital assets, in other words an increasing demand for capital assets. Because the stock of capital assets doesn’t change much in the short run, an increased demand for those assets tends, in the short run, to raise real interest rates as people switch from fixed income assets (bonds) into the real assets associated with increased expected net cash flows. Increased optimism by households about their future income prospects implies that their demand for long-lived assets, real or financial, tends to decline as household devote an increased share of current income to present consumption and less to saving for future consumption, because an increase in future income reduces the amount of current savings needed to achieve a given level of future consumption. The more optimistic I am about my future income, the less I will save in the present. If I win the lottery, I will start spending even before I collect my winnings. The reduced household demand for long-lived assets with which to provide for future consumption reduces the value of such assets, implying, for given expectations of their future yields, an increased real interest rate.

This is the appropriate neoclassical (Fisherian) framework within which to think about the determination of real interest rates. The Fisherian theory may not be right, but I don’t think that we have another theory of comparable analytical power and elegance. Other theories are just ad hoc, and lack the aesthetic appeal of the Fisherian theory. Alas, the world is a messy place, and we have no guarantee that the elegant theory will always win out. Truth and beauty need not the same. (Sigh!)

Commenting on my previous post, Joshua Wojnilower characterized my explanation as “a combination of a Keynesian-demand side story in the first paragraph and an Austrian/Lachmann subjective expectations view in the second section.” I agree that Keynes emphasized the importance of changes in the state of entrepreneurial expectations in causing shifts in the marginal efficiency of capital, and that Austrian theory is notable for its single-minded emphasis on the subjectivity of expectations. But these ideas are encompassed by the Fisherian neoclassical paradigm, entrepreneurial expectations about profits determining the relevant slope of the production possibility curve embodying opportunities for the current and future production of consumption goods on the one hand, and household expectations about future income determining the slope of household indifference curves reflecting their willingness to exchange current for future consumption. So it’s all in Fisher.

Thus, as I observed, falling real interest rates could be explained, under the Fisherian theory, by deteriorating entrepreneurial expectations, or by worsening household expectations about future income (employment). In my previous post, I suggested that, at least since the 2007-09 downturn, entrepreneurial profit expectations have been declining along with the income (employment) expectations of households. However, I am reluctant to suggest that this trend of expectational pessimism started before the 2007-09 downturn. One commenter, Diego Espinosa, offered some good reasons to think that since 2009 entrepreneurial expectations have been improving, so that falling real interest rates must be attributed to monetary policy. Although I find it implausible that entrepreneurial expectations have recovered (at least fully) since the 2007-09 downturn, I take Diego’s points seriously, and I am going to try to think through his arguments carefully, and perhaps respond further in a future post.

I also suggested in my previous post that there might be other reasons why real interest rates have been falling, which brings me to the point of this post. By way of disclaimer, I would say that what follows is purely speculative, and I raise it only because the idea seems interesting and worth thinking about, not because I am convinced that it is empirically significant in causing real interest rates to decline over the past two or three decades.

Almost ten months ago, I discussed the basic idea in a post in which I speculated about why there is no evidence of a strong correlation between reductions in marginal income tax rates and economic growth, notwithstanding the seemingly powerful theoretical argument for such a correlation. Relying on Jack Hirshleifer’s important distinction between the social and private value of information, I argued that insofar as reduced marginal tax rates contributed to an expansion of the financial sector of the economy, reduced marginal tax rates may have retarded, rather than spurred, growth.  The problem with the financial sector is that the resources employed in that sector, especially resources devoted to trading, are socially wasted, the profits accruing to trading reflecting not net additions to output, but losses incurred by other traders. In their quest for such gains, trading establishments incur huge expenses with a view to obtaining information advantages by which profits can be extracted as a result of trading with the informationally disadvantaged.

But financial trading is not the only socially wasteful activity that attracted vast amounts of resources from other (socially productive) activities, i.e., making and delivering real goods and services valued by consumers. There’s a whole set of markets that fall under the heading of winner-take-all markets. There are some who attribute increasing income inequality to the recent proliferation of winner-take-all markets. What distinguishes these markets is that, as the name implies, rewards in these markets are very much skewed to the most successful participants. Participants compete for a reward, and rewards are distributed very unevenly, small differences in performance implying very large differences in reward. Because the payoff at the margin to an incremental improvement in performance is so large, the incentives to devote resources to improve performance are inefficiently exaggerated. Because of the gap between the large private return and the near-zero social return from improved performance, far too much effort and resources is wasted on achieving minor gains in performance. Lance Armstrong is but one of the unpleasant outcomes of a winner-take-all market.

It is also worth noting that competition in winner-take-all markets is far from benign. Sports leagues, which are classic examples of winner-take-all markets, operate on the premise that competition must be controlled, not just to prevent match-ups from being too lopsided, but to keep unrestricted competition from driving up costs to uneconomic levels. At one time, major league baseball had a reserve clause. The reserve clause exists no longer, but salary caps and other methods of controlling competition were needed to replace it. The main, albeit covert, function of the NCAA is to suppress competition for college athletes that would render college football and college basketball unprofitable if it were uncontrolled, with player salaries determined by supply and demand.

So if the share of economic activity taking place in winner-take-all markets has increased, the waste of resources associated with such markets has likely been increasing as well. Because of the distortion in the pricing of resources employed in winner-take-all markets, those resources typically receiving more than their net social product, employers in non-winner-take-all markets must pay an inefficient premium to employ those overpaid resources. These considerations suggest that the return on investment in non-winner-take-all markets may also be depressed because of such pricing distortions. But I am not sure that this static distortion has a straightforward implication about the trend of real interest rates over time.

A more straightforward connection between falling real interest rates and the increase in share of resources employed in winner-take-all markets might be that winner-take-all markets (e.g., most of the financial sector) are somehow diverting those most likely to innovate and generate new productive ideas into socially wasteful activities. That hypothesis certainly seems to accord with the oft-heard observation that, until recently at any rate, a disproportionate share of the best and brightest graduates of elite institutions of higher learning have been finding employment on Wall Street and in hedge funds. If so, the rate of technological advance in the productive sector of the economy would have been less rapid than the rate of advance in the unproductive sector of the economy. Somehow that doesn’t seem like a recipe for increasing the rate of economic growth and might even account for declining real interest rates. Something to think about as you watch the Lance Armstrong interview tomorrow night.

About Me

David Glasner
Washington, DC

I am an economist at the Federal Trade Commission. Nothing that you read on this blog necessarily reflects the views of the FTC or the individual commissioners. Although I work at the FTC as an antitrust economist, most of my research and writing has been on monetary economics and policy and the history of monetary theory. 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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