Risky Sexual Behavior, Testing, and HIV Treatments

This paper studies the impact of antiretroviral therapies (ARVs) 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 ARVs in late 1996 and the sharp increase in risky sexual behavior that ensued. Further, following ARVs, testers take more risks while non-testers take fewer risks. The proportion of testers remains stable, which was ambiguous a priori. To the extent that ARVs may induce changes in the composition of the testing and non-testing groups, such effects do not seem to affect the results.