The "globalization" that produced the tremendous surge in world output over the past two hundred years has entailed not only trade flows and international capital flows, but a dramatic international movement of human beings in pursuit of economic opportunity. But does international migration still have a role in promoting development today? At the dawn of our century, are migrants a burden or a benefit to the economies that send and receive them? And what are the prospects for international migrations' contributions to the world economy in the years ahead? Jeffrey G. Williamson of Harvard University, one of the world's leading economic historians, will address these and other issues at the third Henry Wendt Distinguished Lecture at AEI.