A framework is presented for considering for what health conditions in developing countries the marginal social benefits of demographic and social science research are likely to be relatively high. Based on this framework, it is argued that the relative current and future predicted prevalence of burdens of different health/disease conditions as measured by Disability-Adjusted-Life-Years (DALYs) represent fairly well some important factors related to the relative marginal social benefits of demographic and social science research on different health conditions. World Health Organization (WHO) DALYs projections for 2005-30 are compared with (a) demographic and other social science studies on health in developing countries during 1990-2005 and (b) presentations at the Population Association of America annual meetings during the same time period. These comparisons suggest that, recent demographic and social science research on health in developing countries has overfocused substantially relatively on HIV/AIDS and underfocused substantially relatively on non-communicable diseases.