Unemployment Crises

•Historical U.S. monthly time series of unemployment rates, vacancy rates, and labor productivity, some of which date back to January 1890, are compiled.•A search model of equilibrium unemployment, when calibrated to the mean and volatility of postwar unemployment rates, is a good start to understanding the unemployment crisis in the Great Depression.•The frequency, persistence, and severity of the unemployment crises in the model are quantitatively consistent with those in the historical series.•The measured shock to log labor productivity in 1933 has a magnitude of 3.4 unconditional standard deviations in the postwar sample.•Wage inertia arising from credible bargaining plays a key role in driving the unemployment crises in the model.