The Effect of Weights and Sampling Plans on Price Index Estimates: a Simulation Study

• Activity Number: 471
• Type: Contributed
• Date/Time: Wednesday, August 4, 2010 : 8:30 AM to 10:20 AM
• Sponsor: Section on Government Statistics
• Author(s): Daniele Toninelli*+ and Zdenek Patak
• Companies: University of Bergamo and Statistics Canada
• Keywords: price index ; sample weights ; economic weights ; index bias ; simulation study ; sampling methods

Abstract

Several statistical agencies are developing projects to measure the prices of products and services, given that price index data are more and more important to the study of evolution of the world economy. Therefore, the bias of price indexes is a topic of primary importance; it is often related to the use of updated sample and economic weights. Starting from simulated price relatives (based on survey data) and considering the population of Canadian wholesalers, this work makes a comparative evaluation of the impact of a changing sample and economic weights in different economic areas on the index's bias, defining an index of similarity. Using a simulation study approach, a number of sample selection methods commonly used in practice are also compared, evaluating at the same time how the choice of weights affects the bias of the estimates and the robustness of the sampling plans.