HIV Testing & Risky Sexual Behavior

A puzzle in HIV prevention is that while HIV tests provide important information about a person's health status, it has little e ect on risky sexual behavior. One explanation is that testing only a ects people if it provides new information about their HIV status. Using data from a study that randomly assigns o ers of HIV testing in two urban centers in East Africa, I examine the e ects of testing when people's beliefs about their HIV status are taken into account. In order to objectively measure risky sexual behavior, gonorrhea and chlamydia infections that occurred during the study (sexually transmitted infections or STIs ) are used as proxies. I nd that individuals who believed they were at low risk for HIV before testing, have a six-fold increase in contracting an STI following an HIV-positive test, indicating riskier sexual behavior. Individuals who believed they were at high risk for HIV have a 60% decrease in their likelihood of contracting an STI following an HIV-negative test, indicating safer sexual behavior. When HIV tests agree with a person's belief of HIV infection, there is no statistically signi cant change in contracting an STI. These ndings suggest: 1) HIV tests only a ect behavior if they provide new information and 2) risky sexual behavior is increasing in beliefs of HIV infection; as a person's likelihood of HIV infection increases, the bene t of choosing safe sexual behavior diminishes. I model the e ects of HIV testing on risky sexual behavior using the distribution of beliefs of HIV infection, actual HIV status, and estimated behavioral change derived from this study. I nd the overall number of HIV infections increase when people are tested compared to when they are unaware of their status an unintended consequence of testing. JEL Codes: D84, I18, O12