The typical identification strategy in aid effectiveness studies assumes donor motives do not influence the impact of aid on growth. We call this homogeneity assumption into question, first constructing a model in which donor motives matter and then testing the assumption empirically. -- Aid ;...

We use recent immigration data from 195 countries and propose an index of population diversity based on people's birthplaces. This new index is then decomposed into a size (share of foreign born) and a variety (diversity of immigrants) component and is available for 1990 and 2000 disaggregated...