Résumé en anglais

This paper questions the positive relationship between HIV prevalence and income in Sub-Saharan Africa. In this paper, we hypothesize that a greater economic instability would reduce the incentives to engage in self-protective behaviors inducing people to increasingly take the risk of HIV-infection and hence causing a rise in HIV prevalence. We provide a simple model to stress on the e ects of an increase in income risk in the incentives for protection. We test the prediction using a panel of Sub-Saharan African countries over the period 1980-2001. It is shown that the epidemic is widespread in countries that experience a great instability in gross domestic product over the whole period. When introducing income instability, GDP per capita is devoid of predictive power and the puzzle of the positive relationship between income and prevalence in Africa is lifted. Additional nding states that the risk taking of HIV-infection increases when the individuals are facing frequent and large crop shocks.