. . . we provided a theoretical framework and empirical evidence to shed light on a fundamental question: What barriers prevent the diffusion of the most productive technologies from the technological frontier to less developed economies?The authors argue
. . . populations that share a more recent common history and are therefore closer in terms of vertical traits [that is, the transmission of characteristics which are passed on vertically across generations within a population over the very long run] tend to face lower costs and barriers to adopting each other's technological innovations.