Posner: How I became a Keynesian

Somehow I missed this! Thanks to a reader for pointing it out to me.

Posner was as captured by Chicago School nonsense as anyone else, but at least we learn that he can perform a Bayesian update (i.e., learn from reality) -- posteriors need not be wholly determined by priors :-)

Strangely, I don't see any discussion of this article on the Becker-Posner blog. How do Gary Becker and Robert Lucas feel about the recent apostasy of their colleague?

How I Became a Keynesian, by Richard Posner

... I had never thought to read The General Theory of Employment, Interest, and Money, despite my interest in economics.

... We have learned since September that the present generation of economists has not figured out how the economy works. The vast majority of them were blindsided by the housing bubble and the ensuing banking crisis; and misjudged the gravity of the economic downturn that resulted; and were perplexed by the inability of orthodox monetary policy administered by the Federal Reserve to prevent such a steep downturn; and could not agree on what, if anything, the government should do to halt it and put the economy on the road to recovery. By now a majority of economists are in general agreement with the Obama administration's exceedingly Keynesian strategy for digging the economy out of its deep hole.

... The dominant conception of economics today, and one that has guided my own academic work in the economics of law, is that economics is the study of rational choice. People are assumed to make rational decisions across the entire range of human choice, including but not limited to market transactions, by employing a form (usually truncated and informal) of cost-benefit analysis. The older view was that economics is the study of the economy, employing whatever assumptions seem realistic and whatever analytical methods come to hand. Keynes wanted to be realistic about decision-making rather than explore how far an economist could get by assuming that people really do base decisions on some approximation to cost-benefit analysis.

... It is an especially difficult read for present-day academic economists, because it is based on a conception of economics remote from theirs. This is what made the book seem "outdated" to Mankiw--and has made it, indeed, a largely unread classic. (Another very distinguished macroeconomist, Robert Lucas, writing a few years after Mankiw, dismissed The General Theory as "an ideological event.") The dominant conception of economics today, and one that has guided my own academic work in the economics of law, is that economics is the study of rational choice. People are assumed to make rational decisions across the entire range of human choice, including but not limited to market transactions, by employing a form (usually truncated and informal) of cost-benefit analysis. The older view was that economics is the study of the economy, employing whatever assumptions seem realistic and whatever analytical methods come to hand. Keynes wanted to be realistic about decision-making rather than explore how far an economist could get by assuming that people really do base decisions on some approximation to cost-benefit analysis.

The General Theory is full of interesting psychological observations--the word "psychological" is ubiquitous--as when Keynes notes that "during a boom the popular estimation of [risk] is apt to become unusually and imprudently low," while during a bust the "animal spirits" of entrepreneurs droop. He uses such insights without trying to fit them into a model of rational decision-making.

An eclectic approach to economic behavior came naturally to Keynes, because he was not an academic economist in the modern sense. He had no degree in economics, and wrote extensively in other fields (such as probability theory--on which he wrote a treatise that does not mention economics). He combined a fellowship at Cambridge with extensive government service as an adviser and high-level civil servant, and was an active speculator, polemicist, and journalist. He lived in the company of writers and was an ardent balletomane.

... The third claim that I am calling foundational for Keynes's theory--that the business environment is marked by uncertainty in the sense of risk that cannot be calculated--now enters the picture. Savers do not direct how their savings will be used by entrepreneurs; entrepreneurs do, guided by the hope of making profits. But when an investment project will take years to complete before it begins to generate a profit, its prospects for success will be shadowed by all sorts of unpredictable contingencies, having to do with costs, consumer preferences, actions by competitors, government policy, and economic conditions generally. Skidelsky puts this well in his new book: "An unmanaged capitalist economy is inherently unstable. Neither profit expectations nor the rate of interest are solidly anchored in the underlying forces of productivity and thrift. They are driven by uncertain and fluctuating expectations about the future." Only what Keynes called "animal spirits," or the "urge to action," will persuade businessmen to embark on such a sea of uncertainty. "If human nature felt no temptation to take a chance, no satisfaction (profit apart) in constructing a factory, a railway, a mine or a farm, there might not be much investment merely as a result of cold calculation."

But however high-spirited a businessman may be, often the uncertainty of the business environment will make him reluctant to invest. His reluctance will be all the greater if savers are hesitant to part with their money because of their own uncertainties about future interest rates, default risks, and possible emergency needs for cash to pay off debts or to meet unexpected expenses. The greater the propensity to hoard, the higher the interest rate that a businessman will have to pay for the capital that he requires for investment. And since interest expense is greater the longer a loan is outstanding, a high interest rate will have an especially dampening effect on projects that, being intended to meet consumption needs beyond the immediate future, take a long time to complete.

... An ambitious public-works program can be a confidence builder. It shows that government means (to help) business. "The return of confidence," Keynes explains, "is the aspect of the slump which bankers and businessmen have been right in emphasizing, and which the economists who have put their faith in a ‘purely monetary' remedy have underestimated." In a possible gesture toward Roosevelt's first inaugural ("we have nothing to fear but fear itself"), Keynes remarks upon "the uncontrollable and disobedient psychology of the business world."

See also my talk (for physicists) on the financial crisis. Some related posts on Keynes. Even more on Keynes (12th Wrangler) here.

Keynes

Robert Skidelsky, Keynes' biographer, writes in the Times magazine (excerpted below). Keynes had lived through the greatest of all bubbles and crashes, and saw through the convenient but deeply flawed idea of efficient markets.

As someone with a mathematical bent I was not initially drawn to Keynes' brand of economics -- my interests were in areas of modern finance like option pricing theory, volatility, stochastic models. But like Keynes I have seen a bubble up close -- first in Silicon Valley, and now, from a greater distance, the current credit crisis. What seemed to be reasonable rough approximations: efficient markets, no arbitrage conditions, stochastic processes, etc., have been revealed as terribly naive and dangerous. And so over time my views have come to resemble those described below. (See my talk on the financial crisis, and this Venn diagram.)

Although he is best known as an economist, Keynes' Treatise on Probability, written relatively early in his career, is quite good, and also stresses the idea of probability as a form of logic which goes beyond binary truth values. (See related post on E.T. Jaynes and Bayesian thinking.)

Note to commenters: I am not endorsing all "Keynsian" policy measures. I am endorsing Keynes' opinions on efficient markets, risk and the importance of psychological and sociological factors in economics -- i.e., what is discussed in the excerpt below.

NYTimes: Among the most astonishing statements to be made by any policymaker in recent years was Alan Greenspan’s admission this autumn that the regime of deregulation he oversaw as chairman of the Federal Reserve was based on a “flaw”: he had overestimated the ability of a free market to self-correct and had missed the self-destructive power of deregulated mortgage lending. The “whole intellectual edifice,” he said, “collapsed in the summer of last year.”

[Greenspan quote here.]

What was this “intellectual edifice”? As so often with policymakers, you need to tease out their beliefs from their policies. Greenspan must have believed something like the “efficient-market hypothesis,” which holds that financial markets always price assets correctly.

...By contrast, Keynes created an economics whose starting point was that not all future events could be reduced to measurable risk. There was a residue of genuine uncertainty, and this made disaster an ever-present possibility, not a once-in-a-lifetime “shock.” Investment was more an act of faith than a scientific calculation of probabilities. And in this fact lay the possibility of huge systemic mistakes.

The basic question Keynes asked was: How do rational people behave under conditions of uncertainty? The answer he gave was profound and extends far beyond economics. People fall back on “conventions,” which give them the assurance that they are doing the right thing. The chief of these are the assumptions that the future will be like the past (witness all the financial models that assumed housing prices wouldn’t fall) and that current prices correctly sum up “future prospects.” Above all, we run with the crowd. A master of aphorism, Keynes wrote that a “sound banker” is one who, “when he is ruined, is ruined in a conventional and orthodox way.” (Today, you might add a further convention — the belief that mathematics can conjure certainty out of uncertainty.)

But any view of the future based on what Keynes called “so flimsy a foundation” is liable to “sudden and violent changes” when the news changes. Investors do not process new information efficiently because they don’t know which information is relevant. Conventional behavior easily turns into herd behavior. Financial markets are punctuated by alternating currents of euphoria and panic.

Keynes’s prescriptions were guided by his conception of money, which plays a disturbing role in his economics. Most economists have seen money simply as a means of payment, an improvement on barter. Keynes emphasized its role as a “store of value.” Why, he asked, should anyone outside a lunatic asylum wish to “hold” money? The answer he gave was that “holding” money was a way of postponing transactions. The “desire to hold money as a store of wealth is a barometer of the degree of our distrust of our own calculations and conventions concerning the future. . . . The possession of actual money lulls our disquietude; and the premium we require to make us part with money is a measure of the degree of our disquietude.” The same reliance on “conventional” thinking that leads investors to spend profligately at certain times leads them to be highly cautious at others. Even a relatively weak dollar may, at moments of high uncertainty, seem more “secure” than any other asset, as we are currently seeing.

It is this flight into cash that makes interest-rate policy such an uncertain agent of recovery. If the managers of banks and companies hold pessimistic views about the future, they will raise the price they charge for “giving up liquidity,” even though the central bank might be flooding the economy with cash. That is why Keynes did not think that cutting the central bank’s interest rate would necessarily — and certainly not quickly — lower the interest rates charged on different types of loans. This was his main argument for the use of government stimulus to fight a depression. There was only one sure way to get an increase in spending in the face of an extreme private-sector reluctance to spend, and that was for the government to spend the money itself. Spend on pyramids, spend on hospitals, but spend it must.

This, in a nutshell, was Keynes’s economics. His purpose, as he saw it, was not to destroy capitalism but to save it from itself. He thought that the work of rescue had to start with economic theory itself. Now that Greenspan’s intellectual edifice has collapsed, the moment has come to build a new structure on the foundations that Keynes laid.