from WSJ:
The existing empirical evidence on the response of real gross domestic product to added government spending and tax changes is thin. In ongoing research, we use long-term U.S. macroeconomic data to contribute to the evidence. The results mostly favor tax rate reductions over increases in government spending as a means to increase GDP.... The bottom line is this: The available empirical evidence does not support the idea that spending multipliers typically exceed one, and thus spending stimulus programs will likely raise GDP by less than the increase in government spending. Defense-spending multipliers exceeding one likely apply only at very high unemployment rates, and nondefense multipliers are probably smaller. However, there is empirical support for the proposition that tax rate reductions will increase real GDP.!
