| Wave 4 Survey of Income and Program Participation - 1991 Panel: Topical Modules | SIPP is a nationally representative longitudinal survey that provides comprehensive data about the income and government program participation of individuals and households in the United States. Most interview of the 1991 SIPP Panel included a topical module that asked for detailed information on one of a rotating group of topics. These microdata contain data for these rotating topics. Interviews occurred every four months, with the first interview occurring between February 1991 to May 1991. | 1991 | sipp› topical› 1991panel› wave4 | Microdata | geographies | variables | groups | sorts | examples | documentation | http://api.census.gov/data/1991/sipp/topical/1991panel/wave4 |