Compare methods

	Occupational Gender Segregation Index	Gender Gap Decomposition
Field	Gender Studies	Gender Studies
Family	Process / pipeline	Regression model
Year of origin	1955	1973
Originator	Otis Dudley Duncan & Beverly Duncan	Ronald Oaxaca & Alan Blinder
Type	Distributional segregation index	Regression-based decomposition of a mean group difference
Seminal source	Duncan, O. D., & Duncan, B. (1955). A methodological analysis of segregation indexes. American Sociological Review, 20(2), 210–217.	Oaxaca, R. (1973). Male-female wage differentials in urban labor markets. International Economic Review, 14(3), 693–709.
Aliases	Duncan Dissimilarity Index, Index of Dissimilarity, Sex Segregation Index	Oaxaca-Blinder Decomposition, Blinder-Oaxaca Decomposition, Wage Gap Decomposition
Related	4	3
Summary	Occupational gender segregation indices measure how unevenly women and men are distributed across occupations. The most widely used is the Duncan and Duncan index of dissimilarity, introduced in 1955, which gives the share of women (or men) who would have to change occupations for the two distributions to match. Together with margin-free alternatives and decompositions into horizontal and vertical components, these indices are the standard tools for quantifying the sex segregation of labour markets.	Gender gap decomposition, most often implemented as the Oaxaca-Blinder decomposition, splits the mean difference in an outcome such as wages between men and women into a part explained by differences in measured characteristics (education, experience, occupation) and an unexplained residual part attributed to differences in how those characteristics are rewarded. Introduced independently by Ronald Oaxaca and Alan Blinder in 1973, it is the workhorse method for quantifying how much of the gender pay gap reflects composition versus differential treatment.