Abrupt changes in demographic trends that over the past decades have repeatedly scrambled population forecasts for the United States again require revision of even the most recent projections for the New York Region. Population projections more than merely surmise about the future. They increasingly serve as the raw materials on which business plans and government policies are made. In the Urban Region - which consists of New York City and 26 surrounding counties in Connecticut, New Jersey and New York - population projections depend on changes in national population modified by economic analyses of the Region’s role in the nation’s economy. This report, then, begins with the factors that explain population trends in the United States.