Contributor(s): Professor Tim Besley | Professor Besley gives his inaugural lecture as Sir William Arthur Lewis Chair in Development Economics. A major change in mainstream thinking in economics over the past 25 years has been towards improving our understanding of how the policy process (political and bureaucrat) affects policy outcomes. Such changes in economic thinking are partly in response to the need to have a persuasive account of the diverse historical development experiences of various countries and regions. One key debate following this research has been about whether a particular configuration of institutions is needed to promote inclusive economic development. This lecture will take stock of what has been learned and critically appraise the state of knowledge, drawing some implications for how international financial institutions and aid practitioners approach their business. Tim Besley is Deputy Head for Research of the Department of Economics and an associate member of CEP, IGC and STICERD at LSE. Oriana Bandiera is Professor of Economics and Director of STICERD at LSE. The Department of Economics at LSE (@LSEEcon) is one of the largest economics departments in the world. Its size ensures that all areas of economics are strongly represented in both research and teaching.