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...

We review the theoretical links between growth and agglomeration. Growth, in the form of innovation, can be at the origin of catastrophic spatial agglomeration in a cumulative process la Myrdal. One of the surprising features of the Krugman [Journal of Political Economy 99 (1991) 483499] model,...

Within the field of environmental economics, the role of technological change has received much attention. The long-term nature of many environmental problems, such as climate change, makes understanding the evolution of technology an important part of projecting future impacts. Moreover, in...

This chapter selectively surveys the literature on general purpose technologies (GPTs), focusing on incentives and aggregate growth implications. The literature on classical GPTs (steam, electricity, computers) and on classical great economic transformations (industrial revolutions, the...