Understanding the demographic characteristics of urban men who have sex with men.

We examined migration, closetedness, and family structure explanations of demographic profiles of urban men who have sex with men (MSM) using data from the Urban Men's Health Study and the Public Use Microdata Sample of the U.S. Census. The data suggested that the demographic profiles of urban MSM reflect a large in-migrating white, often young adult, population without children. Closetedness, an oft-cited bias in MSM population studies, did not significantly impact demographic patterns with minor exceptions. MSM urban subpopulations have demographics that differ substantially from the general population of the cities in which they reside.