One of the biggest growth opportunities in the world economy lies not in the mobility of goods or capital, but in the mobility of labour. Many people born in low-income countries would like to leave those countries, but barriers prevent their emigration. Those barriers, according to economists’ best estimates to date, cost the world economy much more than all remaining barriers to the international movement of goods and capital combined. Yet economists spend a great time studying the movement of goods and capital, and when they study migration at all, they focus on the effects of immigration on nonmigrants in destination countries. Dr Michael Clemens will investigate why this is the case and sketch a four-point research agenda on the effects of emigration. Barriers to emigration, Dr Clemens argues, deserve a research priority that is commensurate with their likely colossal economic effects. Michael Clemens is a senior fellow at the Center for Global Development where he leads the Migration and Development initiative. His current research focuses on the effects of international migration on people from and in developing countries, and on rigorous impact evaluation for aid projects. He also serves as CGD’s Research Manager. This lecture is presented by the Development Policy Centre at Crawford School of Public Policy at The Australian National University.