We analyze recent contributions to growth theory based on the model of expanding variety of Romer [Romer, P. (1990). “Endogenous technological change”. Journal of Political Economy 98, 71–102]. In the first part, we present different versions of the benchmark linear model with imperfect...

The British Industrial Revolution triggered a reversal in the social order whereby the landed elite was replaced by industrial capitalists rising from the middle classes as the economically dominant group. Many observers have linked this transformation to the contrast in values between a...

Externalities play a central role in most theories of economic growth. We argue that international externalities, in particular, are essential for explaining a number of empirical regularities about growth and development. Foremost among these is that many countries appear to share a common long...