Aids and population growth in sub-Saharan Africa: Assessing the sensitivity of projections

Despite different models to project the course of the AIDS pandemic and a scarcity of data to provide standard input parameters for those models, a limited consensus emerges from distinct sets of population projections. In sub-Saharan Africa, population growth rates are projected to remain positive in spite of the pandemic over the next few decades. To investigate this conclusion, alternative projections of an HIV/AIDS epidemic and its related mortality are first produced from different sets of input parameters and assumptions. Their incorporation into the population projections of a fast-growing country illustrates the robustness of projected population growth rates under very different scenarios of the future epidemic but with the common assumption that it will not affect the mortality of the uninfected population, fertility nor migration. This paper then shows that the projected growth rates are much less robust when interactions between the epidemic and the demographic regime are allowed and identifies several potential mechanisms for such interactions. In particular, it suggests that improving our confidence in the medium-term projections of the demographic impact of AIDS in the region requires less a refinement of the projections of the epidemic than a better understanding of its impact on the timing of the postulated fertility decline.