As we all know, we are in the middle of what will likely be the worst U.S. economic contraction since the 1930s. In this context and from the history of the Great Depression, I can understand various attempts to prop up the financial system. These efforts, akin to avoiding bank runs in prior periods, recognize that the social consequences of credit-market decisions extend well beyond the individuals and businesses making the decisions.
But, in terms of fiscal-stimulus proposals, it would be unfortunate if the best Team Obama can offer is an unvarnished version of Keynes's 1936 "General Theory of Employment, Interest and Money." The financial crisis and possible depression do not invalidate everything we have learned about macroeconomics since 1936.
Much more focus should be on incentives for people and businesses to invest, produce and work. On the tax side, we should avoid programs that throw money at people and emphasize instead reductions in marginal income-tax rates -- especially where these rates are already high and fall on capital income. Eliminating the federal corporate income tax would be brilliant. On the spending side, the main point is that we should not be considering massive public-works programs that do not pass muster from the perspective of cost-benefit analysis. Just as in the 1980s, when extreme supply-side views on tax cuts were unjustified, it is wrong now to think that added government spending is free.
Barro hits the bull's-eye by emphasizing that incentives matter.