Why it is so hard to find a robust effect of aid on the long-term growth of poor countries, even those with good policies. A possible offset to the beneficial effects of aid is examined using a methodology that exploits both cross-country and within-country variation.

The analysis focuses on immigrants and native-born individuals because employers are likely to have less reliable signals of productivity for an immigrant than a native-born individual. Using multiple data sets, the paper presents a robust empirical finding that the wage gains associated with...