The startling drop in incomes and increase in inequality accompanying the transition to market economies in Eastern Europe and the former Soviet Union raise critical questions: Who is most likely to be poor? How well are existing social assistance programs reaching those who most need help? And what kind of programs would be most effective in reducing poverty? As part of a project analyzing poverty and social assistance in the transition economies, a Bank research team created a database of household expenditure and income data from recent surveys - the HEIDE database. (See the book by J. Braithwaite, Ch. Grootaert and B. Milanovic, "Poverty and social assistance in Transition Countries, St. Martin's Press, 1999" and the book by B. Milanovic, Income, inequality, and poverty during the transition from planned to market economy, World Bank, 1998.)The HEIDE database includes four countries in both Eastern Europe and the Former Soviet Union. Latvia was then added at a later stage.The four files are:-hhold: Household data consists of the variables in Variable List at household level.-ind: Individual data consists of the variables in Variable List at individual level.-modelh: Household data consists of the variables used in regression models.-modeli: Individual data consists of the variables used in regression models.Prefixes are used to indicate countries for the data files, i.e.A- Rural ArmeniaB- BulgariaE- EstoniaH- HungaryK- KyrgyzP- PolandR- RussiaS- SlovakY- Urban ArmeniaThe survey data were cleaned for possible inconsistencies and errors and adjusted for missing data and outliers. The compilation of almost 100 variables with similar definitions for the eight countries allows ready cross-country analysis and comparisons. A consistent syntax is used for the variables to enable researchers to use the same macro routines across countries. There are more than 3 million data points.