Compare methods

	Glass Ceiling Index	Occupational Gender Segregation Index
Field	Gender Studies	Gender Studies
Family	Process / pipeline	Process / pipeline
Year of origin	2001	1955
Originator	David Cotter, Joan Hermsen, Seth Ovadia & Reeve Vanneman	Otis Dudley Duncan & Beverly Duncan
Type	Distributional gender-gap criterion / index	Distributional segregation index
Seminal source	Cotter, D. A., Hermsen, J. M., Ovadia, S., & Vanneman, R. (2001). The glass ceiling effect. Social Forces, 80(2), 655–681.	Duncan, O. D., & Duncan, B. (1955). A methodological analysis of segregation indexes. American Sociological Review, 20(2), 210–217.
Aliases	Glass Ceiling Measure, Glass-Ceiling Effect Index, Glass Ceiling Coefficient	Duncan Dissimilarity Index, Index of Dissimilarity, Sex Segregation Index
Related	4	4
Summary	The glass ceiling index and related distributional measures quantify the 'glass ceiling' — the tendency for gender disadvantage to intensify toward the top of a wage distribution or organisational hierarchy. Cotter and colleagues (2001) set out formal criteria distinguishing a true ceiling from a general gap, while labour economists operationalise it as a widening female–male gap at high quantiles of earnings, and popular indices (such as The Economist's) rank countries by women's representation in senior roles, pay, and leadership.	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.