We define a class of bias problems that arise when purchasers shift their expenditures among sellers charging different prices for units of precisely defined and interchangeable product items that are nevertheless regarded as different for the purposes of price measurement. For...

Although inflation is much feared for its negative effects on the economy, how to measure it is a matter of considerable debate that has important implications for interest rates, monetary supply, and investment and spending decisions. Underlying many of these issues is the concept of the...