השוואת שיטות

	Equivalence Scale Analysis	Atkinson Index	Foster-Greer-Thorbecke Index
תחום	כלכלה	Sociology	כלכלה
משפחה	Process / pipeline	Process / pipeline	Process / pipeline
שנת המקור	1980	1970	1984
הוגה השיטה	Foundations in Deaton & Muellbauer (1980); cross-country sensitivity by Buhmann et al. (1988)	Anthony Barnes Atkinson	James Foster, Joel Greer & Erik Thorbecke
סוג	Welfare-comparability adjustment	Welfare-based, parameterized inequality index	Parametric class of poverty measures
מקור מכונן	Deaton, A., & Muellbauer, J. (1980). Economics and Consumer Behavior. Cambridge: Cambridge University Press. ISBN: 9780521296762	Atkinson, A. B. (1970). On the measurement of inequality. Journal of Economic Theory, 2(3), 244–263.	Foster, J., Greer, J., & Thorbecke, E. (1984). A class of decomposable poverty measures. Econometrica, 52(3), 761–766.
כינויים	Equivalence Scales, Household Equivalence Scale, OECD Equivalence Scale, Adult Equivalent Scale	Atkinson inequality measure, Atkinson's A, welfare-based inequality index	FGT Index, FGT Poverty Measures, P-alpha Poverty Index, Foster-Greer-Thorbecke Poverty Measure
קשורות	3	5	4
תקציר	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 Atkinson index is a welfare-based measure of inequality that incorporates an explicit, analyst-chosen parameter for how much society dislikes inequality. Introduced by Anthony Atkinson in 1970, it asks what fraction of total income could be discarded, under an equal distribution, while leaving social welfare unchanged — making the ethical judgement behind any inequality comparison transparent rather than hidden.	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.