HIV Testing and Risky Sexual Behaviour

Using a study that randomly assigns HIV testing in two sites in sub‐Saharan Africa, I examine the effects of testing on sexual behaviour. Using sexually transmitted infections as markers of risky sex, I find behavioural responses to HIV tests when tests provide unexpected information. Individuals surprised by an HIV‐positive (HIV‐negative) test increase (decrease) their risky sexual behaviour. I simulate the effects of testing and find under certain conditions, new HIV infections increase when people are tested. The provision of anti‐retrovirals for HIV‐positive individuals immediately after testing mitigates these effects and leads to decreases in HIV infections in all cases.