Comparer des méthodes

	Foster-Greer-Thorbecke Index	Datt-Ravallion Decomposition
Domaine	Économie	Économie
Famille	Process / pipeline	Process / pipeline
Année d'origine	1984	1992
Auteur d'origine	James Foster, Joel Greer & Erik Thorbecke	Gaurav Datt & Martin Ravallion
Type	Parametric class of poverty measures	Poverty-change decomposition
Source fondatrice	Foster, J., Greer, J., & Thorbecke, E. (1984). A class of decomposable poverty measures. Econometrica, 52(3), 761–766.	Datt, G., & Ravallion, M. (1992). Growth and redistribution components of changes in poverty measures: a decomposition with applications to Brazil and India in the 1980s. Journal of Development Economics, 38(2), 275–295.
Alias	FGT Index, FGT Poverty Measures, P-alpha Poverty Index, Foster-Greer-Thorbecke Poverty Measure	Growth-Redistribution Decomposition, Datt-Ravallion Method, Growth and Redistribution Components, Poverty Change Decomposition
Apparentées	4	3
Résumé	The Foster-Greer-Thorbecke (FGT) index is a parametric class of poverty measures introduced by James Foster, Joel Greer, and Erik Thorbecke in 1984 that became the workhorse of applied poverty analysis. A single parameter alpha tunes how much weight the measure places on the depth and distribution of poverty: alpha = 0 gives the headcount ratio (the share of people below the poverty line), alpha = 1 gives the poverty gap (the average normalized shortfall), and alpha = 2 gives poverty severity (which weights larger shortfalls more heavily). Its defining virtue is additive decomposability — total poverty is the population-weighted sum of subgroup poverty — which makes it ideal for profiling poverty across regions, sectors, and demographic groups.	The Datt-Ravallion decomposition, introduced by Gaurav Datt and Martin Ravallion in 1992, separates the observed change in a poverty measure between two dates into a growth component — the change attributable to a shift in mean income holding the relative distribution fixed — and a redistribution component — the change attributable to a shift in the Lorenz curve holding mean income fixed. A residual captures the interaction between the two. It became the standard way to ask whether falling poverty was driven by rising average incomes or by changes in inequality, and underlies the empirical literature on pro-poor growth.