Supply shocks and the distribution of price changes

Since the early 1970s, economists have gained an increased appreciation for the importance of supply shocks as sources of fluctuations in aggregate economic activity. Yet the question of how best to measure such shocks remains open. Traditionally, economists have assessed the importance of such shocks by looking at such things as the relative prices of oil or agricultural commodities. Recently, however, it has been suggested that changes in the distribution of price changes for individual commodities may, in fact, be a superior indicator of changes in aggregate supply conditions. In this article, Nathan Balke and Mark Wynne assess this argument in the context of a very simple but well-known model of the aggregate economy. They show that fluctuations in the rate of technological progress across sectors are indeed reflected in the cross-section distribution of prices, lending support to the idea that this may be a superior measure of supply shocks. However, Balke and Wynne raise questions about the interpretation of the relationship between changes in the distribution of price changes for individual commodities and aggregate inflation as evidence of price stickiness.