Andrew T. Levin of Dartmouth College and NBER reviews “Monetary Policy and Its Unintended Consequences” by Raghuram Rajan. The EconLit abstract of this book begins: “Details how monetary adventurism can have unintended effects and promotes policy that is moderate and focused on combating high inflation and financial instability.”

The volatility of U.S. real GDP growth since 1984 has been markedlylowerthanoverthepreviousquartercentury.Weutilizefrequency-domain and VAR methods to distinguish among competing explanations for this reduction: improvements in monetary policy, better business practices, and a fortuitous reduction in exogenous disturbances. We find that reduced innovation variances account for much of the decline in aggregate output volatility, suggesting that good luck is the most likely explanation. Good practices and good policy appear to have played a more important role in explaining the post-1984 decline in the volatility of consumer price inflation.

We investigate the performance of forecast-based monetary policy rules using five macroeconomic models that reflect a wide range of views on aggregate dynamics. We identify the key characteristics of rules that are robust to model uncertainty; such rules respond to the one-year-ahead inflation forecast and to the current output gap and incorporate a substantial degree of policy inertia. In contrast, rules with longer forecast horizons are less robust and are prone to generating indeterminacy. Finally, we identify a robust benchmark rule that performs very well in all five models over a wide range of policy preferences.