Trends in international prices

Abstract

We exploit the panel dimension of a price levels dataset for more than one hundred product items across 140 cities in 90 countries for the period from 1990 to 2009 in order to improve our understanding of international price dispersion and the evolution of prices over time. We consider a panel data model with exchangeable units that allows for the possibility of common components for different dimensions of the panel. This allows one to gauge the contribution of each dimension of the data to total variation and to disentangle the sources of potential non-stationarity. It also allows us to identify differences in the speed of convergence for different time-varying components in response to location-specific, product-specific, and idiosyncratic shocks. Finally, we proceed to identify the economic determinants of different components to show that particular dimensions of the data are more suited for examining particular theories.