Comparability of statistical data between countries is a major objecti
ve for international statistical organisations such as EUROSTAT. The c
onvergence criteria set down in the Maastricht Treaty explicitly requi
re comparable consumer price indices in the European Union. We present
an empirical analysis, largely based on simulations with Swedish and
Finnish CPI data, of various potential sources of noncomparability, co
nceptual as well as technical ones.