Despite the onset of globalization, year-by-year cross-country regressions of the gravity model usually suggest that the impediment of geographical distance on bilateral trade is rising, and not declining, over time. This effect of distance is dubbed the distance puzzle. In this paper, we argue...

We estimate the effect of exports on HIV incidence for sub-Saharan African countries, using an instrument related to the Baltic Dry Index. We find that a doubling of exports per capita could increase HIV incidence by about 55% on average.