Zum Keynes-Jubiläum

Auch John Cassidy hat sich anlässlich des 75-jährigen Erscheinungsjubiläums des großen Werks "The General Theory of Employment, Interest and Money" mit Keynes und dem Keynesianismus beschäftigt:

But the real essence of Keynes, I eventually decided, can be expressed in these terms:

1. In the short-run, demand is what drives economies, not prices.

2. In a demand-driven economy, many types of unfavorable and self-sustaining outcomes are possible, including lengthy slumps.

3. The role of the government is to sustain demand and help the economy avoid such disastrous outcomes.

I regard these statements as truisms, even though others would dispute them, to varying degrees. Once you get beyond them, things get murky. For example, like most economists of a certain age, I was brought up on the “I.S.L.M.” model, a toy version of Keynesianism due to Sir John Hicks, which allows you to depict the entire economy in the form of two simple curves: one representing investment and saving, the other the supply and demand for money. In policy terms, the I.S.L.M. setup remains immensely useful. Whenever I hear somebody saying, “We should cut taxes on X,” or, “The Fed should do Y,” I automatically think to myself: “What would that do to the I.S. and L.M. curves?” I’d be willing to bet that many of the economists who work at the White House and the Fed go through a similar exercise.

But I.S.L.M. is a crude form of Keynesianism. It depends on the assumption that prices are fixed, which is obviously not true. Conservative economists have always posed this question: In a depressed economy, why won’t prices and wages adjust to restore a full-employment “equilibrium”? Keynes’s answer, which it must be said he never fully integrated into what modern economists would recognize as a “model,” had to do with uncertainty and crowd psychology. When “animal spirits” are depressed, he pointed out, the mere availability of cheap money and cheap labor won’t be sufficient to make businesses invest and expand. Rather, the economy will get stuck in rut.