Justin Fox is needlessly worried. He writes:
The uncertainty of stimulus :: The Curious Capitalist - TIME.com: From a Congressional Budget Office estimate released today on the impact of some amendment or other to the Senate stimulus bill:
The macroeconomic impacts of any economic stimulus program are very uncertain. Economic theories differ in their predictions about the effectiveness of stimulus. Furthermore, large fiscal stimulus is rarely attempted, so it is difficult to distinguish among alternative estimates of how large the macroeconomic effects would be. For those reasons, some economists remain skeptical that there would be any significant effects, while others expect very large ones.
It's sort of like that mutual fund boilerplate, "Past performance is no guarantee of future results." Except that we're not even sure of what the past performance was. (And I say this as somebody who thinks the stimulus legislation is on balance a good idea.)
Well, why should we be certain of what past performance was? There haven't been a great many uses of large-scale fiscal policy to try to cure depression. And in those cases in which it has been tried, a lot else has been going on.
But when fiscal boost was tried on a large enough scale, it certainly did the job. And it is reasonable to infer (with all the caveats provided by the CBO) that what is true in the very large will be true in the merely large as well. Eugene Fama says that it is theoretically impossible for fiscal stimulus to boost output: World War II proves him wrong. Robert Barro says that the multiplier is zero: World War II proves him wrong. Benn Steil says that Jacques Rueff in 1947 conclusively proved that fiscal policy could not boost employment: World War II proves him wrong.
The extent to which the Great Depression and World War II changed how economists thought--and how those who know their history still think--cannot be overstated. And even those economists who don't know their history should be forced to come up with a reason why the lessons of the Great Depression do not apply to today.
As I am going to say in class a couple of weeks from now:
The end in the Great Depression of laissez faire--the idea that the government should keep its hands off of the economy--as a doctrine for guiding economic policy did not mean the end of the market economy as a social resource allocation mechanism. "Keynesianism" and the doctrine of the "mixed economy" that it supported emerged in the nick of time, soon became the ruling ideologies in the industrial core of the world economy, and provided North America and western Europe with a Keynesian escape route from what had seemed the insoluble crises of the interwar period.
The Keynesian escape route opened up key ground in the middle between fascist-style regimentation and socialist-style national planning. Keynes argued that the market economy and capitalist order could be salvaged, and salvaged by relatively minor reforms. An activist welfare-state government with a commitment to full employment had the tools to eliminate Great Depressions, and could put economies back onto the road to Utopia. If only governments would reduce interest rates to get private agents or would themselves spend money freely (without raising taxes) in times when total demand was low, and raise interest rates to reduce private spending and themselves raise taxes (without raising spending) in times when total demand was high, then fiuctuations in employment and production could be greatly reduced, and Great Depressions avoided.
Belief in this escape route was strongly reinforced by facts. Those countries that had tried it by accident during the Depression--had infiated early, printed money, ensured low interest rates, and run large budget deficits--managed to survive the Depression much more easily than others. World War II provided final proof, were any necessary--"vindication by Mars," as John Kenneth Galbraith calls it. That component of unemployment, called "structural" or "permanent" during the 1930s, that was seemingly-immune to both the self-adjusting forces of the market and the armament of the New Deal vanished entirely in the 1940s as the federal budget deficit approached and then exceeded the levels that had long been recommended by John Maynard Keynes. And the United States fought World War II without reducing civilian consumption: all of U.S. war production came from new capacity or from capacity that stood idle at the end of the 1930s.
Demand expansion--deliberate attempts by governments to put the unemployed back to work by deficit spending and loose-money low interest rate policies--was successful in the 1930s and 1940s. It put the unemployed back to work. It did not contain within itself the seeds of a renewed Great Depression. It did not explode into hyperinflation. The coming of "stablization policy" enlarged the policy steps that could be undertaken without forcing a definitive break with the market-capitalist order, and without forcing a choice between Hitler's way and Stalin's.
In later years--in the second and third post-World War II generation--tasks of macroeconomic management would prove harder, and the truth of the doctrines of Keynes's disciples if not of the doctrines of Keynes himself would become less clear.