Board on Earth Sciences and Resources; Committee on Population; Division on Earth and Life Studies; Division of Behavioral and Social Sciences and Education; National Research Council; National Research Council; National Academy of Sciences ; Board on Earth Sciences and Resources ; Committee on Population ; Committee on the Effective Use of Data, Methodologies, and Technologies to Estimate Subnational Populations at Risk ; Division of Behavioral and Social Sciences and Education ; Division on Earth and Life Studies ; National Academy of Sciences