title: The outlook for population growth.
abstract: Projections of population size, growth rates, and age distribution, although extending to distant horizons, shape policies today for the economy, environment, and government programs such as public pensions and health care. The projections can lead to costly policy adjustments, which in turn can cause political and economic turmoil. The United Nations projects global population to grow from about 7 billion today to 9.3 billion in 2050 and 10.1 billion in 2100, while the Old Age Dependency Ratio doubles by 2050 and triples by 2100. How are such population projections made, and how certain can we be about the trends they foresee?
authors.affiliation: Department of Demography, University of California at Berkeley, 2232 Piedmont Avenue, Berkeley, CA 94720, USA. rlee@demog.berkeley.edu
authors.forename: Ronald
authors.initials: R
authors.lastname: Lee
mesh_terms: D017677:Age Distribution; D001723:Birth Rate / Q000639:trends; D003710:Demography; D004641:Emigration and Immigration; D005260:Female; D005544:Forecasting; D006801:Humans; D008017:Life Expectancy; D008297:Male; D009026:Mortality / Q000639:trends; D011157:Population Dynamics; D011158:Population Growth; D035501:Uncertainty; D014480:United Nations