Andrew J Tatem works for the University of Southampton, and is Director of WorldPop. His research on mapping populations has been funded by donors such as the Gates Foundation, Wellcome Trust, GAVI.

Pew Research Center conducted this research to understand changes in the unauthorized immigrant population in the United States. The Center has published estimates of the U.S. unauthorized immigrant ...

Three key demographic forces have reshaped the overall U.S. population in recent years: growing racial and ethnic diversity, increasing immigration and rising numbers of older adults. But these trends ...