理解政府支出乘数的大小：关键在于符号

Abstract This article argues that an important, yet overlooked, determinant of the government spending multiplier is the direction of the fiscal intervention. Regardless of whether we identify government spending shocks from (1) a narrative approach or (2) a timing restriction, we find that the contractionary multiplier—the multiplier associated with a negative shock to government spending—is above 1 and largest in times of economic slack. In contrast, the expansionary multiplier—the multiplier associated with a positive shock—is substantially below 1 regardless of the state of the cycle. These results help understand seemingly conflicting results in the literature. A simple theoretical model with incomplete financial markets and downward nominal wage rigidities can rationalize our findings.