Suchergebnisse

This report deals with age-specific fertility rate (ASFR) models from the perspective of their possible use in subnational population forecasting, as opposed to graduating empirical data. Gompertz, beta-1, Mazur, Coale–Trussell, and Page models are discussed first, with attention being paid to correspondence of functional elements to empirical ASFR component behavior. New functional models or descriptions of natural fertility rates, cumulative nuptiality proportions, deviations from natural fertility, and mean age at nuptiality for females of various marriage durations are then presented. Existing model elements and the new functional forms are combined into three new ASFR models. The report concludes with an evaluation of all the models.

Traditional methods of projecting age-specific migration for local areas are based on inflexible migration patterns. Ideally, forecast results should be isomorphic with the intent of the forecaster, so flexible models are called for. To this end, a parameterized model that incorporates directional flows is presented along with a theoretical scheme for its operation. It is asserted that the new model provides much of the needed flexibility, but at the cost of added complexity.