We construct a matrix showing the share of the year 2000 population in every country that is descended from people in different source countries in the year 1500. Using the matrix to adjust indicators of early development so that they reflect the history of a population's ancestors rather than...

We model growth and technology transfer in a world where technologies are specific to particular combinations of inputs. Unlike the usual specification, our model does not imply that an improvement in one technique for producing a given good improves all other techniques for producing that good....

I use microeconomic estimates of the effect of health on individual outcomes to construct macroeconomic estimates of the proximate effect of health on GDP per capita. I employ a variety of methods to construct estimates of the return to health, which I combine with cross-country and historical...