A standard international socio-economic index of occupational status

In this paper we present an International Socio-Economic Index of occupational status (ISEI), derived from the International Standard Classification of Occupations (ISCO), using comparably coded data on education, occupation, and income for 73,901 full-time employed men from 16 countries. We use an optimal scaling procedure, assigning scores to each of 271 distinct occupation categories in such a way as to maximize the role of occupation as an intervening variable between education and income (in contrast to taking prestige as the criterion for weighting education and income, as in the Duncan scale). We compare the resulting scale to two existing internationally standardized measures of occupational status, Treiman's international prestige scale (SIOPS) and Goldthorpe's class categories (EGP), and also with several locally developed SEI scales. The performance of the new ISEI scale compares favorably with these alternatives, both for the data sets used to construct the scale and for five additional data sets.