This collection includes data derived from Household Income and Expenditure Surveys (HIES). These surveys are designed to produce information on the expenditure, income and living conditions of households. HIES provide data required to assess trends in economic well-being and to determine and update the basket of consumer goods and services and weights used for the calculation of the Consumer Price Index. They are also used to measure poverty, inequality, and social exclusion. The data are widely used for formulating and monitoring economic and social welfare policies, especially for different segments of the population, such as the elderly, low-income households, or single parent households, among others.

Data on household income and expenditure may also be collected using income surveys, household budget surveys, or living standard measurement surveys. These surveys may be conducted through interviews and/or completion of questionnaires by households (the retrospective method). They may also be implemented using the diary method, in which households are requested to regularly enter all or some of their receipts and expenditures for a given period into a diary.

National HIES, representing all private households in the country, are usually undertaken at intervals not exceeding five years, but in many countries, they are carried out on an annual basis.