手法を比較

	Net Migration Rate	コーホート要因法人口予測
分野	人口学	人口学
系統	Process / pipeline	Process / pipeline
提唱年	1976	2001
提唱者	Classical vital-statistics measure (formalized by Shryock & Siegel)	Preston, Heuveline & Guillot
種類	Rate of net population change due to migration per unit population	Demographic projection pipeline
原典	Preston, S. H., Heuveline, P., & Guillot, M. (2001). Demography: Measuring and Modeling Population Processes. Blackwell. ISBN: 9781557864512	Preston, S. H., Heuveline, P., & Guillot, M. (2001). Demography: Measuring and Modeling Population Processes. Blackwell. ISBN: 978-1-557-86451-2
別名	Net Migration Ratio, Crude Net Migration Rate, Net Migration per 1000	Cohort-Component Method, Component Method of Population Projection, Age-Sex-Specific Population Projection, Kohort-Bileşen Projeksiyonu
関連	4	3
概要	The net migration rate expresses the net effect of migration on a population's size as a rate: net migration — in-migrants minus out-migrants over a period — divided by the population at risk, conventionally stated per 1000 people. It is the migration counterpart to the rate of natural increase and a standard component of population accounting. Because directional migration flows are often poorly recorded, net migration is frequently not counted directly but estimated as a residual from the demographic balancing equation or by comparing surviving cohorts across two censuses.	Cohort-Component Projection is the standard demographic method for forecasting future population size and age-sex structure by explicitly tracking births, deaths, and migration for each age-sex cohort across discrete time steps. Systematically formalized in the textbook literature by Preston, Heuveline, and Guillot (2001), the method builds on foundational actuarial and demographic work dating to the early twentieth century and remains the workhorse technique used by national statistical offices and international organizations worldwide.