Beyond Six Billion: Forecasting the World's Population

摘要

Future trends in population size, age structure, births, and other demographicvariables are of interest to a wide range of analysts, including policymakers, scientists, and planners in industry and government. For example, global and national trends in population size are needed to project the future demand for food, water, and energy and the environmental impact of rising consumption of natural resources. Subnational projections help planners decide where to build new schools and where investments in roads and other infrastructure are required. Reliable estimates of the number of retired people in need of pensions and health care are essential to the optimal design of social security systems.