Should prevention campaigns disclose the transmission rate of HIV/AIDS? Theory and evidence from Burundi

Among non-specialists, the estimates of the HIV/AIDS transmission rate are generally upwardly biased. This overestimation may be perceived as a godsend, as it increases the incentives to have protected sexual relationships. However, a pernicious effect may counterbalance this positive effect. Combined with the overestimation of the transmission rate, an occasional unprotected sexual encounter may induce the feeling that “the die is cast”, and hence lead to a permanent neglect of condom use. In this paper, I construct a model that reflects such insidious and unexpected behavior. I calculate that the optimal transmission rate to be disclosed for safer sexual practices ranges between 5 % and 24.9 %.