手法を比較

	Spatial Exposure Index	Spatial Gini Concentration Index
分野	Human Geography	Human Geography
系統	Process / pipeline	Process / pipeline
提唱年	1954	1991
提唱者	Wendell Bell (P* indices); Douglas Massey & Nancy Denton (segregation dimensions)	Corrado Gini (coefficient); locational adaptation in regional science / economic geography
種類	Segregation measure of the potential contact or isolation between population groups	Descriptive index of how unevenly an activity is distributed across space
原典	Bell, W. (1954). A probability model for the measurement of ecological segregation. Social Forces, 32(4), 357–364.	Duncan, O. D., & Duncan, B. (1955). A methodological analysis of segregation indexes. American Sociological Review, 20(2), 210–217.
別名	Exposure Index, Isolation Index, P-star Index	Locational Gini Coefficient, Spatial Gini Index, Geographic Concentration Index, Gini Index of Spatial Inequality
関連	4	4
概要	The exposure and isolation indices, written P*, measure residential segregation as the degree of potential contact between population groups across the neighbourhoods of a region. Developed by Wendell Bell in 1954 and later codified by Massey and Denton in 1988 as the 'exposure' dimension of segregation, they answer a different question from evenness measures like the dissimilarity index: not how unevenly groups are distributed, but how much members of one group actually share neighbourhoods with members of another or only with their own. The interaction index gauges cross-group exposure while the isolation index gauges within-group concentration, each interpretable as a probability.	The spatial (or locational) Gini concentration index adapts the classic Gini coefficient to geography, summarizing in a single number between zero and one how unevenly an activity — an industry, a population group, a resource — is distributed across spatial units relative to a benchmark such as total population or land area. It is the workhorse measure for quantifying geographic concentration and agglomeration in economic geography.