This volume is the culmination of Institute investigations on the relationship between foreign direct investment (FDI) and development. Today, more than one-third of world trade takes place in the form of intrafirm transactions—that is, trade among the various parts of the same corporate network spread across borders—and the bulk of technology is transferred within the confines of integrated international production systems. This means that FDI and the operations of multinational corporations have become central to the world economy at large. Nowhere is this more important than for developing countries. But as Theodore Moran argues in this new volume, FDI is not a single phenomenon. FDI has such different impacts in the extractive sector, infrastructure, manufacturing and assembly, and services—and presents such distinctive policy challenges—that each broad category of FDI must be treated on its own terms. Indeed, past studies that have aggregated all FDI flows together to try to find some unique relationship to host-country growth or welfare have led to unreliable substantive findings and, sometimes, mistaken policy conclusions. Moran examines each of the principal forms of FDI, extracts the best from previous analysis, and offers new findings and perspectives about how benefits from FDI in each sector can be enhanced and potential damages limited or eliminated.