We document properties of business cycles in ten countries over the last hundred years, contrasting the behavior of real quantities with that of the price level and the stock of money. Although the magnitude of output fluctuations has varied across countries and periods, relations among variables have been remarkably uniform. Consumption has generally been about as variable as output, and investment substantially more variable, and both have been strongly procydical. The trade balance has generally been countercyclical. The exception to this regularity is government purchases, which exhibit no systematic cyclical tendency. With respect to the size of output fluctuations, standard deviations are largest between the two world wars. In some countries (notably Australia and Canada) they are substantially larger prior to World War I than after World War II, but in others (notably Japan and the United Kingdom) there is little difference between these periods. Properties of price levels, in contrast, exhibit striking differences between periods. Inflation rates are more persistent after World War II than before, and price level fluctuations are typically procyclical before World War II, countercyclical afterward. We find no general tendency toward increased persistence in money growth rates, but find that fluctuations in money are less highly correlated with output in the postwar period.