Evaluating Imperfections and Biases in Price Indexes during Transition

The rapidly changing environment of the transition may create special problems for calculation of index numbers that require a fixed basket of goods and outlets. Using referent-level data we find that using a fixed-weight Laspeyres Index may overstate inflation rates by approximately 5 per cent a year when compared with a superlative index in the Czech Republic. We find no evidence of such problems using more aggregate data for Bulgaria and Hungary. This suggests that the extent of the problems discovered might have been even greater if we had been able to use item/store level data.