List prices vs. bargain prices: which solution to estimate consumer price indices?

Alternative approaches to CPI surveys are here evaluated, in markets where final prices are based on some sort of price listing. Three types of surveys are compared: local surveys (LOC), with small samples and a local price collection; list price surveys (LIS), with huge samples and centralised collection; mixed surveys (MXD), in which LOC and LIS are jointly used. Based on a multiplicative pricing model, some conditions are derived to establish the relative efficiency of these approaches. The alternatives have also been tested on five different random populations. LIS surveys appear very efficient under very restrictive hypotheses on the regularity of discount policies. LOC surveys may be efficient only if the variability of list prices is reasonably low. MXD surveys appear the most promising solution if a correction parameter is introduced to account for the covariance between list prices and discount policies. MXD surveys appear better positioned for monitoring consumer market and the range of products available to the consumer.