Risky Sexual Behavior, Testing and New HIV Treatments

This paper studies the impact of new HIV therapies (HAART) on HIV testing and risky sexual behavior. I use data collected in San Francisco among a high-risk population from 1994 to 2002. The evidence supports the hypothesis of a causal link between the introduction of HAART in late 1996 and the sharp increase in risky sexual behavior that ensued. Further, following HAART, testers take more risks while non-testers take fewer risks. The proportion of testers remains stable, which was ambiguous a priori, and HAART does not alter the composition of the testing and non-testing groups.