As americans spread out, immigration plays a crucial role in local population growth

New Census Bureau population estimates for counties and metropolitan areasconfirm that after concentrating in big cities and major metro areas during the first part of this decade, Americans are spreading out again into suburbs, exurbs, and smaller towns and rural areas.The new numbers, which track annual population trends through July 2018, indicate that for the first time this decade, the nation’s three largest metropolitan areas—New York, Los Angeles, and Chicago—all lost population. At the same time, outer suburban, exurban, and non-metropolitan counties nationwide registered renewed growth. Although there are some exceptions in growing parts of the country, the latest data reveal that broad-based population “concentration” toward large urban areas in the early 2010s was an aberration related to the post-recession economy and housing crunch.