Revisiting taste change in cost-of-living measurement

Robert S. Martin

Abstract

This paper derives conditional cost-of-living indexes (COLI) for the Constant Elasticity of Substitution model in the presence of taste change. Recent proposals to incorporate changing tastes reflect a different conceptual target (an unconditional COLI) from a consumer price index (a conditional COLI), and a strong implicit assumption (cardinal utility). Using Nielsen retail scanner data for food and beverage products, I find that tastes can dominate prices in unconditional COLI estimates, while they have smaller impacts on conditional COLI. Using CPI data, I find that category-level tastes have a relatively minor average effect on an all-items price index.