All of the data for the UNIFEM-WIEGO studies were from the late 1990s and early 2000s. The data sources and years for the five countries were as follows:
- Egypt: ELMS 1998 and the Micro and Small Enterprise Survey (MSE) 2003
- El Salvador: Encuesta de Hogares de Propositos Multiples (EHPM) 2003
- South Africa: Labor Force Survey September 2003
- Costa Rica: Encuesta Permanente de Hogares de Propositos Multiples 2003
- Ghana: Ghana Living Standards Survey 1998/199
Two analyses of data from India are cited in the Links with Poverty section. The first in an analysis of the National Sample Survey 1999-2000 (55th. round) and 2000 “Report on Statistical Studies Relating to Informal Economy in India” by N.S. Sastry. The second is an analysis of poverty estimates of households classified by main source of income and by social groups by G. Raveendran, who used the same estimation method, data set (Consumer Expenditure Survey 2011-12) and poverty lines of the Expert Group (2012-14) on measurement of poverty headed by C. Rangarajan.
The data for the recent analysis by Mike Rogan of segmentation and earnings within the informal economy of South Africa was from the 2015 South African Quarterly Labour Force Surveys (Rogan and Alfers 2019).