The evolution of the world economy over the past decades has been complex. There have been interrelated changes in resource accumulation, population growth, growth in knowledge, and improvements in production technology, all operating in an environment characterised by frequent and dramatic transformations in politics and institutions. In this overview we touch briefly on a number of these themes and their relationship to the ongoing debate about the role and effectiveness of foreign aid. The discussion draws on the chapters in this volume, which go into much more detail on particular issues.