Gender inequality has been identified by UNAIDS as a key driver of the HIV epidemic. In Sub-Saharan Africa, where two-thirds of all HIV-infected people live, young women are up to eight times more likely than men to be infected. Using panel data from the Malawi Diffusion and Ideational Change Project MDICP, this research analyzes the importance of intra-household bargaining power in the context of HIV prevention (i.e., condom use within marriage and HIV-related spousal communication) and risky sexual behavior (i.e., self-reported male extramarital behavior). Data on spouses as well as junior wives (in the case of polygamous marriages) has been matched, which enables for a simultaneous assessment of changes in intra-household bargaining power of both partners. The panel dimension of the data allows me to capture unobserved heterogeneity and time trends by using individual-specific fixed effects and time dummies. Speaker: Berit Gerritzen, WAPPP Fellow, University of St. Gallen