Comparer des méthodes

	Equivalence Scale Analysis	Foster-Greer-Thorbecke Index	Gini Coefficient
Domaine	Économie	Économie	Sociology
Famille	Process / pipeline	Process / pipeline	Process / pipeline
Année d'origine	1980	1984	1912
Auteur d'origine	Foundations in Deaton & Muellbauer (1980); cross-country sensitivity by Buhmann et al. (1988)	James Foster, Joel Greer & Erik Thorbecke	Corrado Gini
Type	Welfare-comparability adjustment	Parametric class of poverty measures	Scalar measure of statistical dispersion / inequality
Source fondatrice	Deaton, A., & Muellbauer, J. (1980). Economics and Consumer Behavior. Cambridge: Cambridge University Press. ISBN: 9780521296762	Foster, J., Greer, J., & Thorbecke, E. (1984). A class of decomposable poverty measures. Econometrica, 52(3), 761–766.	Ceriani, L., & Verme, P. (2012). The origins of the Gini index: extracts from Variabilità e Mutabilità (1912) by Corrado Gini. The Journal of Economic Inequality, 10(3), 421–443.
Alias	Equivalence Scales, Household Equivalence Scale, OECD Equivalence Scale, Adult Equivalent Scale	FGT Index, FGT Poverty Measures, P-alpha Poverty Index, Foster-Greer-Thorbecke Poverty Measure	Gini index, Gini ratio, Gini concentration ratio, G
Apparentées	3	4	5
Résumé	Equivalence scales convert a household's total income or consumption into a measure of the living standard of its members, adjusting for the fact that larger households need more resources but also share them — there are economies of scale in housing, utilities, and durables, and children typically cost less than adults. Dividing household resources by the scale yields equivalized income, the per-equivalent-adult quantity that makes welfare comparable across households of different size and composition. The theory traces to Deaton and Muellbauer's treatment in Economics and Consumer Behavior (1980), and Buhmann and colleagues' 1988 cross-country study showed that inequality and poverty rankings can be strikingly sensitive to which scale is chosen.	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 Gini coefficient is the most widely used single-number summary of inequality in a distribution such as income or wealth. Introduced by the Italian statistician Corrado Gini in 1912, it equals twice the area between the Lorenz curve and the line of perfect equality, ranging from 0 when everyone has the same amount to a maximum approaching 1 when one unit holds everything.