Posts Tagged 'Kevin Donoghue'

Nick Rowe Teaches Us a Lot about Apples and Bananas

Last week I wrote a post responding to a post by Nick Rowe about money and coordination failures. Over the weekend, Nick posted a response to my post (and to one by Brad Delong). Nick’s latest post was all about apples and bananas. It was an interesting post, though for some reason – no doubt unrelated to its form or substance – I found the post difficult to read and think about. But having now read, and I think, understood (more or less), what Nick wrote, I confess to being somewhat underwhelmed. Let me try to explain why I don’t think that Nick has adequately addressed the point that I was raising.

That point being that while coordination failures can indeed be, and frequently are, the result of a monetary disturbance, one that creates an excess demand for money, thereby leading to a contraction of spending, and thus to a reduction of output and employment, it is also possible that a coordination failure can occur independently of a monetary disturbance, at least a disturbance that could be characterized as an excess demand for money that triggers a reduction in spending, income, output, and employment.

Without evaluating his reasoning, I will just restate key elements of Nick’s model – actually two parallel models. There are apple trees and banana trees, and people like to consume both apples and bananas. Some people own apple trees, and some people own banana trees. Owners of apple trees and owners of banana trees trade apples for bananas, so that they can consume a well-balanced diet of both apples and bananas. Oh, and there’s also some gold around. People like gold, but it’s not clear why. In one version of the model, people use it as a medium of exchange, selling bananas for gold and using gold to buy apples or selling apples for gold and using gold to buy bananas. In the other version of the model, people just barter apples for bananas. Nick then proceeds to show that if trade is conducted by barter, an increase in the demand for gold, does not affect the allocation of resources, because agents continue to trade apples for bananas to achieve the desired allocation, even if the value of gold is held fixed. However, if trade is mediated by gold, the increased demand for gold, with prices held fixed, implies corresponding excess supplies of both apples and bananas, preventing the optimal reallocation of apples and bananas through trade, which Nick characterizes as a recession. However, if there is a shift in demand from bananas to apples or vice versa, with prices fixed in either model, there will be an excess demand for bananas and an excess supply of apples (or vice versa). The outcome is suboptimal because Pareto-improving trade is prevented, but there is no recession in Nick’s view because the excess supply of one real good is exactly offset by an excess demand for the other real good. Finally, Nick considers a case in which there is trade in apple trees and banana trees. An increase in the demand for fruit trees, owing to a reduced rate of time preference, causes no problems in the barter model, because there is no impediment to trading apples for bananas. However, in the money model, the reduced rate of time preference causes an increase in the amount of gold people want to hold, the foregone interest from holding more having been reduced, which prevents optimal trade with prices held fixed.

Here are the conclusions that Nick draws from his two models.

Bottom line. My conclusions.

For the second shock (a change in preferences away from apples towards bananas), we get the same reduction in the volume of trade whether we are in a barter or a monetary economy. Monetary coordination failures play no role in this sort of “recession”. But would we call that a “recession”? Well, it doesn’t look like a normal recession, because there is an excess demand for bananas.

For both the first and third shocks, we get a reduction in the volume of trade in a monetary economy, and none in the barter economy. Monetary coordination failures play a decisive role in these sorts of recessions, even though the third shock that caused the recession was not a monetary shock. It was simply an increased demand for fruit trees, because agents became more patient. And these sorts of recessions do look like recessions, because there is an excess supply of both apples and bananas.

Or, to say the same thing another way: if we want to understand a decrease in output and employment caused by structural unemployment, monetary coordination failures don’t matter, and we can ignore money. Everything else is a monetary coordination failure. Even if the original shock was not a monetary shock, that non-monetary shock can cause a recession because it causes a monetary coordination failure.

Why am I underwhelmed by Nick’s conclusions? Well, it just seems that, WADR, he is making a really trivial point. I mean in a two-good world with essentially two representative agents, there is not really that much that can go wrong. To put this model through its limited endowment of possible disturbances, and to show that only an excess demand for money implies a “recession,” doesn’t seem to me to prove a great deal. And I was tempted to say that the main thing that it proves is how minimal is the contribution to macroeconomic understanding that can be derived from a two-good, two-agent model.

But, in fact, even within a two-good, two-agent model, it turns out there is room for a coordination problem, not considered by Nick, to occur. In his very astute comment on Nick’s post, Kevin Donoghue correctly pointed out that even trade between an apple grower and a banana grower depends on the expectations of each that the other will actually have what to sell in the next period. How much each one plants depends on his expectations of how much the other will plant. If neither expects the other to plant, the output of both will fall.

Commenting on an excellent paper by Backhouse and Laidler about the promising developments in macroeconomics that were cut short because of the IS-LM revolution, I made reference to a passage quoted by Backhouse and Laidler from Bjorn Hansson about the Stockholm School. It was the Stockholm School along with Hayek who really began to think deeply about the relationship between expectations and coordination failures. Keynes also thought about that, but didn’t grasp the point as deeply as did the Swedes and the Austrians. Sorry to quote myself, but it’s already late and I’m getting tired. I think the quote explains what I think is so lacking in a lot of modern macroeconomics, and, I am sorry to say, in Nick’s discussion of apples and bananas.

Backhouse and Laidler go on to cite the Stockholm School (of which Ohlin was a leading figure) as an example of explicitly dynamic analysis.

As Bjorn Hansson (1982) has shown, this group developed an explicit method, using the idea of a succession of “unit periods,” in which each period began with agents having plans based on newly formed expectations about the outcome of executing them, and ended with the economy in some new situation that was the outcome of executing them, and ended with the economy in some new situation that was the outcome of market processes set in motion by the incompatibility of those plans, and in which expectations had been reformulated, too, in the light of experience. They applied this method to the construction of a wide variety of what they called “model sequences,” many of which involved downward spirals in economic activity at whose very heart lay rising unemployment. This is not the place to discuss the vexed question of the extent to which some of this work anticipated the Keynesian multiplier process, but it should be noted that, in IS-LM, it is the limit to which such processes move, rather than the time path they follow to get there, that is emphasized.

The Stockholm method seems to me exactly the right way to explain business-cycle downturns. In normal times, there is a rough – certainly not perfect, but good enough — correspondence of expectations among agents. That correspondence of expectations implies that the individual plans contingent on those expectations will be more or less compatible with one another. Surprises happen; here and there people are disappointed and regret past decisions, but, on the whole, they are able to adjust as needed to muddle through. There is usually enough flexibility in a system to allow most people to adjust their plans in response to unforeseen circumstances, so that the disappointment of some expectations doesn’t become contagious, causing a systemic crisis.

But when there is some sort of major shock – and it can only be a shock if it is unforeseen – the system may not be able to adjust. Instead, the disappointment of expectations becomes contagious. If my customers aren’t able to sell their products, I may not be able to sell mine. Expectations are like networks. If there is a breakdown at some point in the network, the whole network may collapse or malfunction. Because expectations and plans fit together in interlocking networks, it is possible that even a disturbance at one point in the network can cascade over an increasingly wide group of agents, leading to something like a system-wide breakdown, a financial crisis or a depression.

But the “problem” with the Stockholm method was that it was open-ended. It could offer only “a wide variety” of “model sequences,” without specifying a determinate solution. It was just this gap in the Stockholm approach that Keynes was able to fill. He provided a determinate equilibrium, “the limit to which the Stockholm model sequences would move, rather than the time path they follow to get there.” A messy, but insightful, approach to explaining the phenomenon of downward spirals in economic activity coupled with rising unemployment was cast aside in favor of the neater, simpler approach of Keynes. No wonder Ohlin sounds annoyed in his comment, quoted by Backhouse and Laidler, about Keynes. Tractability trumped insight.

Unfortunately, that is still the case today. Open-ended models of the sort that the Stockholm School tried to develop still cannot compete with the RBC and DSGE models that have displaced IS-LM and now dominate modern macroeconomics. The basic idea that modern economies form networks, and that networks have properties that are not reducible to just the nodes forming them has yet to penetrate the trained intuition of modern macroeconomists. Otherwise, how would it have been possible to imagine that a macroeconomic model could consist of a single representative agent? And just because modern macroeconomists have expanded their models to include more than a single representative agent doesn’t mean that the intellectual gap evidenced by the introduction of representative-agent models into macroeconomic discourse has been closed.


Further Thoughts on Capital and Inequality

In a recent post, I criticized, perhaps without adequate understanding, some of Thomas Piketty’s arguments about capital in his best-selling book. My main criticism is that Piketty’s argument that. under capitalism, there is an inherent tendency toward increasing inequality, ignores the heterogeneity of capital and the tendency for new capital embodying new knowledge, new techniques, and new technologies to render older capital obsolete. Contrary to the simple model of accumulation on which Piketty relies, the accumulation of capital is not a smooth process; it is a very uneven process, generating very high returns to some owners of capital, but also imposing substantial losses on other owners of capital. The only way to avoid the risk of owning suddenly obsolescent capital is to own the market portfolio. But I conjecture that few, if any, great fortunes have been amassed by investing in the market portfolio, and (I further conjecture) great fortunes, once amassed, are usually not liquidated and reinvested in the market portfolio, but continue to be weighted heavily in fairly narrow portfolios of assets from which those great fortunes grew. Great fortunes, aside from being dissipated by deliberate capital consumption, also tend to be eroded by the loss of value through obsolescence, a process that can only be avoided by extreme diversification of holdings or by the exercise of entrepreneurial skill, a skill rarely bequeathed from generation to generation.

Applying this insight, Larry Summers pointed out in his review of Piketty’s book that the rate of turnover in the Forbes list of the 400 wealthiest individuals between 1982 and 2012 was much higher than the turnover predicted by Piketty’s simple accumulation model. Commenting on my post (in which I referred to Summers’s review), Kevin Donoghue objected that Piketty had criticized the Forbes 400 as a measure of wealth in his book, so that Piketty would not necessarily accept Summers’ criticism based on the Forbes 400. Well, as an alternative, let’s have a look at the S&P 500. I just found this study of the rate of turnover in the 500 firms making up the S&P 500, showing that the rate of turnover in the composition of the S&P 500 has been increased greatly over the past 50 years. See the chart below copied from that study showing that the average length of time for firms on the S&P 500 was over 60 years in 1958, but by 2011 had fallen to less than 20 years. The pace of creative destruction seems to be accelerating


From the same study here’s another chart showing the companies that were deleted from the index between 2001 and 2011 and those that were added.


But I would also add a cautionary note that, because the population of individuals and publicly held business firms is growing, comparing the composition of a fixed number (400) of wealthiest individuals or (500) most successful corporations over time may overstate the increase over time in the rate of turnover, any group of fixed numerical size becoming a smaller percentage of the population over time. Even with that caveat, however, what this tells me is that there is a lot of variability in the value of capital assets. Wealth grows, but it grows unevenly. Capital is accumulated, but it is also lost.

Does the process of capital accumulation necessarily lead to increasing inequality of wealth and income? Perhaps, but I don’t think that the answer is necessarily determined by the relationship between the real rate of interest and the rate of growth in GDP.

Many people have suggested that an important cause of rising inequality has been the increasing importance of winner-take-all markets in which a few top performers seem to be compensated at very much higher rates than other, only slightly less gifted, performers. This sort of inequality is reflected in widening gaps between the highest and lowest paid participants in a given occupation. In some cases at least, the differences between the highest and lowest paid don’t seem to correspond to the differences in skill, though admittedly skill is often difficult to measure.

This concentration of rewards is especially characteristic of competitive sports, winners gaining much larger rewards than losers. However, because the winner’s return comes, at least in part, at the expense of the loser, the private gain to winning exceeds the social gain. That’s why all organized professional sports engage in some form of revenue sharing and impose limits on spending on players. Without such measures, competitive sports would not be viable, because the private return to improve quality exceeds the collective return from improved quality. There are, of course, times when a superstar like Babe Ruth or Michael Jordan can actually increase the return to losers, but that seems to be the exception.

To what extent other sorts of winner-take-all markets share this intrinsic inefficiency is not immediately clear to me, but it does not seem implausible to think that there is an incentive to overinvest in skills that increase the expected return to participants in winner-take-all markets. If so, the source of inequality may also be a source of inefficiency.

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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