เปรียบเทียบวิธี

	Rogers-Castro Migration Schedule	Migration Effectiveness Index
สาขาวิชา	Migration Studies	Migration Studies
ตระกูล	Regression model	Process / pipeline
ปีกำเนิด	1981	2002
ผู้ริเริ่ม	Andrei Rogers & Luis J. Castro	Martin Bell and colleagues
ประเภท	Parametric curve-fitting model for age-specific migration rates	Descriptive index of migration efficiency and impact
แหล่งต้นตำรับ	Rogers, A., & Castro, L. J. (1981). Model Migration Schedules. IIASA Research Report RR-81-30.	Bell, M., Blake, M., Boyle, P., Duke-Williams, O., Rees, P., Stillwell, J., & Hugo, G. (2002). Cross-national comparison of internal migration: issues and measures. Journal of the Royal Statistical Society: Series A, 165(3), 435-464.
ชื่อเรียกอื่น	Model Migration Schedule, Rogers-Castro Curve, Multi-Exponential Migration Schedule, Age Profile of Migration	Migration Efficiency Index, Aggregate Net Migration Rate, ANMR, MEI
ที่เกี่ยวข้อง	3	3
สรุป	The Rogers-Castro migration schedule is a parametric model that captures the remarkably regular way migration rates vary with age. Across countries and eras, the probability of moving is high in infancy, falls through childhood, surges to a sharp peak in the early adult labour-force years, and often shows a secondary bump around retirement. Andrei Rogers and Luis Castro, working at the International Institute for Applied Systems Analysis, formalized this regularity in their 1981 monograph as a sum of exponential and double-exponential curves whose parameters have direct demographic meaning. The simplest version uses seven parameters to describe the childhood decline and the labour-force peak; nine- and eleven-parameter extensions add retirement and post-retirement components. Fitting the schedule by nonlinear least squares smooths noisy age-specific rates, allows missing or sparse data to be filled in, and yields interpretable indices — the mean age of the labour-force peak, its sharpness, and the spacing between the childhood and labour curves. The result is a compact, comparable summary of an entire age profile of migration that feeds directly into multiregional projection and the analysis of migration selectivity.	The migration effectiveness index measures how efficiently the gross churning of people between regions actually redistributes population, by expressing net migration as a share of total migration turnover. Two regions can each exchange enormous numbers of migrants and yet end up with almost unchanged populations, because the inflows and outflows nearly cancel; the same net change could instead arise from a small, lopsided, highly directed flow. The effectiveness index distinguishes these cases: it runs from near zero, where gross flows are balanced and population is barely redistributed, toward one hundred, where migration is so one-directional that almost every move contributes to net change. Martin Bell and colleagues codified this measure in their influential 2002 framework for cross-national comparison of internal migration, alongside companion indices of overall migration intensity and the aggregate net migration rate, which combines intensity and effectiveness into a single summary of how much migration reshapes the settlement pattern. Together these indices form a standard toolkit for describing and comparing migration systems across countries and over time.