International Socio-Economic Index of Occupational Status (ISEI)

International Socio-Economic Index of Occupational Status (ISEI)

The International Socio-Economic Index of Occupational Status combines income and education to reflect the status of an occupation (cf. Ganzeboom et al. 1992). The lowest value of the index is 16 (e.g., unskilled workers and cleaning staff) and the highest 90 (judges) (cf. Ganzeboom/Treiman 1996).

Origin/Creator: Harry B. G. Ganzeboom, Donald J. Treiman
Method/Structure: The ISEI-08 bases on the International Social Survey Programme (ISSP). Information on the occupation and education level of 198,500 men and women were used to calculate the ISEI-08. The procedure is comparable to the previous one (see next paragraph) (cf. Ganzeboom 2010).
Maximising the indirect influence of education on income (via occupation) and minimising the direct influence by controlling for age leads to the calculation of the ISEI values measuring education by years of schooling. Considering education as a relative good addresses the problem that the number of years of schooling required for certain occupations varies internationally. The ISEI considers a national ranking of years of schooling which is then subjected to a z-transformation. The income was divided by the national mean and subjected to a logarithmic transformation first, before it was then subjected to a z-transformation (to avoid outliers in income, boundaries for the z-values were set at -3.7 and 3.7). To calculate the status values, an iterative algorithm developed by Jan de Leeuw (for more information on the algorithm, see Ganzeboom et al. 1992: 52f.) was used (Ganzeboom et al. 1992: 10ff.). The ISEI bases on 31 databases from 16 countries, each analysing men aged between 21 to 64 years who work at least 30 hours per week (Ganzeboom et al. 1992: 10ff.).
Development/implementation for Germany: The coding of the ISEI-08 bases on the ISCO-08. Originally, the values were formed using ISCO-88 data, but the ISCO-88 values were converted into ISCO-08 values. The lowest value of the index is 11.01 (e.g., arable farmers/livestock farmers) and the highest 88.96 (e.g., judges) (cf. Ganzeboom 2010).
For Germany, the status value is built on the ZUMA Standard Demography 1976-80, which selected male employed persons aged between 21 to 64 with full-time employment (cf. Schimpl-Neimanns 2004: 2f.).
The original scale, renewed in 1996 by Ganzeboom and Treiman, allows coding the ISEI with the ISCO-88 (cf. Schimpl-Neimanns 2004: 2f.).

International Socio-Economic Index of Occupational Status (ISEI)

Fundamental literature: Ganzeboom, B.G. (2010): Questions and answers about ISEI-08.
http://www.harryganzeboom.nl/isco08/qa-isei-08.htm, Stand: 29.03.2021.

Ganzeboom, Harry B.G., Treiman, Donald J. (1996): Internationally comparable measures of occupational status for the 1988 International Standard Classification of Occupations. Social science research, 25, 201-239.

Ganzeboom, Harry B.G., De Graaf, Paul M., Treiman, Donald J. (1992): A standard international socio-economic index of occupational status. Social science research, 21(1), 1-56.

Schimpl-Neimanns, Bernhard (2004): Zur Umsetzung des Internationalen Sozioökonomischen Index des beruflichen Status (ISEI). ZUMA-Nachrichten, 54(28), 154-170.

Further literature: Albrecht, Andrea, Trappmann, Mark, Wolf, Christof (2002): Statusmaße light: Statusskalen bei unzureichenden Berufsangaben. KZfSS Kölner Zeitschrift für Soziologie und Sozialpsychologie, 54(2), 343-361.

Ganzeboom, Harry B.G., Treiman, Donald J. (2003): Three internationally standardised measures for comparative research on occupational status. Advances in cross-national comparison: A European working book for demographic and socio-economic variables, 159-193.

Hauser, Robert M., Warren, John Robert (1997): Socioeconomic indexes for occupations: A review, update, and critique. Sociological methodology, 27(1), 177-298.