M. Giovanna Merli is a Professor of Public Policy and Sociology and a member of the Duke Global Health Institute. Her research straddles three disciplinary realms: demography, contemporary Chinese society and global health. She focuses on a range of population and health issues in developing countries that intersect frontline public policy, such as the role of China's population control program in lowering fertility preferences and fertility rates in China, the social and behavioral determinants of HIV and other sexually transmitted diseases and the evaluation of methodological approaches to sample hard-to-reach and hidden populations at high risk of acquiring HIV/AIDS. Merli combines her passion for demography and her 20-years experience with living in, studying and conducting research in China in her most recent work. China is a very low HIV prevalence setting but infection rates are high in some population groups whose behaviors are driving the Chinese epidemic. Thus, it is crucial to understand the social and behavioral patterns that put population groups with different risk profiles in contact with each other. Merli's work examines the social and behavioral factors that create conditions which lead individuals in China to acquire HIV infection. This work is crucial to inform the design of appropriate interventions to prevent further spread of infection. Merli also studies HIV/AIDS in another, very different setting of the global HIV epidemic, South Africa, where the AIDS morbidity and mortality crises are tantamount to a perturbation of the age structure. HIV/AIDS in South Africa mostly affects individuals in the mid-adult ages and her work focuses on understanding the consequences of this mortality and morbidity crisis for families and households. Research in China is my comparative advantage.