In a recent article, Nowak-Lehmann, Dreher, Herzer, Klasen, and Martínez-Zarzoso (2012) (henceforth NDHKM) conclude that foreign aid has not had a significant effect on income, based on evidence from panel data potentially covering 131 countries over the period 1960-2006. The present study...

Theoretical models of growth reveal that either exogenous or endogenous, technology is the main driving force behind the long-run economic growth. Furthermore, in the endogenous growth framework, diffusion of technology is the basic mechanism of per capita income convergence among countries....