The Long-Run Effects of Monetary Policy

A well-worn tenet holds that monetary policy does not affect the long-run productive capacity of the economy. Merging data from two new international historical databases, we find this not to be quite right. Using the trilemma of international finance, we find that exogenous variation in monetary policy affects capital accumulation, and to a lesser extent, total factor productivity, thereby impacting output for a much longer period of time than is customarily assumed. We build a quantitative medium- scale DSGE model with endogenous TFP growth to understand the mechanisms at work. Following a monetary shock, lower output temporarily slows down TFP growth. Internal propagation of the monetary shock extends the slow down in productivity, and eventually lowers trend output. Yet the model replicates conventional textbook results in other dimensions. Monetary policy can have long-run effects.