مقایسهٔ روش‌ها

	UNIDIFF Mobility Model	Intergenerational Elasticity
حوزه	Sociology	Sociology
خانواده	Regression model	Regression model
سال پیدایش	1992	1992
پدیدآور	Yu Xie; Robert Erikson & John Goldthorpe (parallel)	Gary Solon (modern estimation)
نوع	Log-multiplicative model for comparing association across tables	Regression-based measure of intergenerational income persistence
منبع بنیادین	Xie, Y. (1992). The log-multiplicative layer effect model for comparing mobility tables. American Sociological Review, 57(3), 380–395.	Solon, G. (1992). Intergenerational income mobility in the United States. American Economic Review, 82(3), 393–408.
نام‌های دیگر	UNIDIFF model, log-multiplicative layer effect model, uniform difference model, Xie-Erikson-Goldthorpe model	IGE, intergenerational income elasticity, intergenerational income persistence, father-son income elasticity
مرتبط	4	5
خلاصه	The uniform difference (UNIDIFF) model, equivalently the log-multiplicative layer effect model, compares the strength of origin–destination association across several mobility tables — countries, time periods, or birth cohorts. It assumes the tables share a common pattern of association ψ_ij but allows the overall strength of that pattern to differ by a single layer-specific multiplier φ_k. A φ_k above one means stronger origin effects (less fluidity) in that layer; below one means greater fluidity.	The intergenerational elasticity of income (IGE) is the workhorse measure of economic mobility: the regression coefficient from regressing a child's adult log income on the parent's log income. It expresses the percentage by which a child's expected income rises for each one-percent increase in parental income, so a higher IGE means income advantages and disadvantages are more strongly transmitted across generations and society is less mobile.