Explaining the Rise in HIV/AIDS among Black Women: The Effects of Sex Ratios on Concurrency, Condom Use and Age of Sexual Debut

Christopher Cornwell, University of Georgia
Scott Cunningham, University of Georgia

Epidemiologists are at a loss as to why the spread of HIV/AIDS differs so much for Blacks. Adimora and Schoenbach (2003; 2004; 2005) hypothesize that low black sex ratios have caused an increase in concurrent sexual partnerships by inducing females to match with men who are already matched and/or men to pursue numerous concurrent partners. We argue low sex ratios also influence condom use and the age of sexual debut, two other behavioral choices that affect disease transmission. Using the NLSY 1997 and the 2000 Census IPUMS, we estimate the effect of sex ratios have on the number of recent partners, condom use, and age of first sex. We show that a 10% increase in the sex ratio causes Black males to reduce the number of partners they had in the previous twelve months by about 13%. We also find higher sex ratios associated with higher propensities of condom use.