By the Numbers: Gay and Lesbian Census; March 2005; Scientific American Magazine; by Rodger Doyle; 1 Page(s)

Tabulating the U.S. gay and lesbian populations has never been easy. Not only are many people reluctant to discuss intimate matters, but also their sense of identity evolves: today's gay man may have been straight yesterday. Like past efforts, the 2000 U.S. decennial census undoubtedly undercounted them, but it does provide substantial new information--specifically, on those gays and lesbians who live together as couples.

The census form asked respondents to classify any unrelated people in their household as a housemate, boarder, foster child, unmarried partner or other nonrelative. If the unmarried partner is reported to be of the same sex, that partner and the respondent are very likely gay or lesbian. The census showed that 0.6 percent of men and 0.5 percent of women 18 years of age and older live together as same-sex unmarried partners. The data provide a good indication of geographic distribution. The map shows the proportion of households that are gay or lesbian, and because of the likelihood of undercounting, it categorizes the dispersion of this population by quintiles, rather than by absolute percentages. The map combines the three middle quintiles for simplicity.