Twelve percent of the Malawian population is HIV infected. Eighteen percent of sexual encounters are casual. A condom is used a third of the time. To analyze the Malawian epidemic, a choice‐theoretic general equilibrium search model is constructed. In the developed framework, people select...

In this paper, we generalize the notion of Pareto efficiency to make it applicable to environments with endogenous populations. Two efficiency concepts are proposed: 𝒫-efficiency and 𝒜-efficiency. The two concepts differ in how they treat potential agents that are not born. We show that these...