Prevention or treatment? The introduction of a new antimalarial drug in Angola

In spite of massive efforts to generalize efficient prevention, such as insecticide-treated mosquito nets (ITN) or long-lasting insecticidal nets (LLINs), malaria remains prevalent in many countries and ITN/LLINs are still only used to a limited extent. We present a simple theoretical model of household preventive behavior in response to malaria prevalence. The novelty is to include a trade-off between prevention and treatment which depends on the relative price of treatment with respect to prevention. We show that a relatively low price of treatment reduces prevention. However, this result depends on endemicity and income distribution. Next, we test the model and estimate the effect of the introduction of an effective treatment on prevention behaviors in the case of malaria. We rely on microeconomic data and build up a difference-in-differences analysis of individuals prevention behaviors following the introduction of Artemisinin Combination Therapies (ACTs) in Angola. We exploit differences in terms of treatment intensity across geographic areas and differences in individuals exposure to the introduction of ACTs. Our results suggest that the increase in access to treatment for malaria in Angola may have had a negative impact on the use of Insecticide Treated Nets even though the two were jointly promoted over the period. The effect disappears for the poorest category and the treatment effect is higher in higher endemicity levels.