방법 비교

	Bilateral Migration Flow Imputation	Migration Effectiveness Index
분야	Migration Studies	Migration Studies
계열	Process / pipeline	Process / pipeline
기원 연도	2019	2002
창시자	Guy J. Abel & Joel E. Cohen; Guy J. Abel	Martin Bell and colleagues
유형	Imputation pipeline for completing origin-destination migration matrices	Descriptive index of migration efficiency and impact
원전	Abel, G. J., & Cohen, J. E. (2019). Bilateral international migration flow estimates for 200 countries. Scientific Data, 6, 82.	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.
별칭	Origin-Destination Flow Imputation, Country-Pair Migration Matrix Completion, Harmonized Bilateral Flow Estimation, Migration Matrix Imputation	Migration Efficiency Index, Aggregate Net Migration Rate, ANMR, MEI
관련	3	3
요약	Bilateral migration flow imputation fills in the complete origin-destination matrix of how many people moved between every pair of countries when the directly reported data cover only a fraction of those pairs and are defined inconsistently from one reporter to the next. The reporting problem is severe: some countries count migrants by intended duration of stay, others by change of registration, others not at all, and a flow reported by the sending country rarely matches the same flow reported by the receiving country. Abel and Cohen's 2019 work, building on Abel's 2013 stock-based estimation, treats this as a matrix-completion problem: harmonize whatever fragments exist, derive consistent row and column totals — often from migrant-stock change — and then fill the empty and unreliable cells so the finished matrix matches those totals. The cells are filled with iterative proportional fitting and a pseudo-Bayesian estimator that blends sparse counts toward a structured prior, and the resulting flows can be refined into sex- and age-specific tables. The output is a single, internally consistent, fully populated bilateral flow table for all country pairs.	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.