Compare methods

	UNIDIFF Mobility Model	Social Mobility Table
Field	Sociology	Sociology
Family	Regression model	Process / pipeline
Year of origin	1992	1927 (concept); 1970s–1980s (modern analysis)
Originator	Yu Xie; Robert Erikson & John Goldthorpe (parallel)	Pitirim Sorokin; refined by Hauser, Hout, Featherman
Type	Log-multiplicative model for comparing association across tables	Cross-classification of social origins by destinations
Seminal source	Xie, Y. (1992). The log-multiplicative layer effect model for comparing mobility tables. American Sociological Review, 57(3), 380–395.	Hauser, R. M. (1978). A structural model of the mobility table. Social Forces, 56(3), 919–953.
Aliases	UNIDIFF model, log-multiplicative layer effect model, uniform difference model, Xie-Erikson-Goldthorpe model	mobility table, intergenerational mobility table, origin-destination table, transition table analysis
Related	4	5
Summary	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.	A social mobility table is a cross-classification of individuals by their social origin (typically a parent's class or occupation) and their own destination class, forming the empirical foundation of intergenerational mobility research. Analyzing it separates how much people move between classes, distinguishes movement forced by changing class sizes from genuine exchange, and isolates the underlying origin–destination association that measures the openness of a society.