The consumer price index (CPI) measures the rate at which the prices of consumer goods and services are changing over time. It is a key statistic for economic and social policymaking and has substantial and wide-ranging implications for governments, businesses, and households. This important and comprehensive Manual provides guidelines for statistical offices and other agencies responsible for constructing CPIs, and explains in-depth the methods that are used to calculate a CPI. It also examines the underlying economic and statistical concepts and principles needed for making choices in efficient and cost-effective ways, and for appreciating the full implications of those choices. The International Labour Office, IMF, OECD, Statistical Office of the European Communities (Eurostat), UN Economic Commission for Europe, and World Bank Collaborated in preparing the Manual.