As fertility rates fall, immigration is becoming the decisive factor in determining the long-run prospects for population and economic growth in the developed world. Yet despite its importance, projections of international migration by official government agencies in the United States and abroad are based on little more than ad hoc assumptions. The U.S. Social Security Administration has asked GAI to draw on immigration theory, empirical evidence, and expert opinion to develop a new methodological framework for projecting future immigration. The purpose of the project is to help U.S. policy experts better understand the factors that influence long-term trends in immigration—and thus ultimately to improve long-term projection techniques.
