Bio: (1921–2004) American sociologist. Otis Dudley Duncan received his PhD from the University of Chicago, and was a professor at universities of Penn State, Wisconsin, Chicago, Michigan, Arizona, and California, Santa Barbara.

Otis Dudley Duncan’s most influential work was his collaboration with Peter M. Blau on The American Occupational Structure (1967). Drawing on the first large-scale national survey of social mobility in the United States, Blau and Duncan demonstrated that parents primarily pass on their social status to their children through educational attainment. Their findings suggested that mobility typically occurs through gradual, incremental steps rather than dramatic leaps up the social hierarchy. The study was groundbreaking in its comprehensive, intergenerational approach, examining how family background, education, race, region, community size, and other factors shape men’s occupational outcomes.

Duncan played a central role in transforming postwar American sociology into a quantitatively rigorous, empirically grounded discipline. Among his major contributions was the introduction of path analysis to sociology, which helped lay the foundation for the development and wider use of structural equation modeling in the social sciences. He also created the Duncan Socioeconomic Index, a systematic measure of occupational status, and developed an index to assess residential segregation between Black and white populations in Chicago. In collaboration with econometrician Arthur Goldberger, Duncan demonstrated the close relationship between path analysis, simultaneous equation models in economics, and confirmatory factor analysis in psychology. He further advanced methodological tools such as loglinear and Rasch models for analyzing categorical data.

In his final book, Notes on Social Measurement, Historical and Critical (1984), Duncan turned to the philosophical foundations of social measurement. He emphasized the inherent challenges of quantitative research in the social sciences, where variability is the rule rather than the exception. A defining feature of his intellectual legacy was his caution against drawing sweeping, law-like causal claims from statistical findings. Skeptical of attempts to model sociology on the natural sciences, Duncan instead argued that empirical reality—not the search for universal social laws—should remain the central guiding principle of quantitative research.

Main works

Statistical Geography: Problems in Analysing Areal Data (1961);

The American Occupational Structure (1967);

Notes on Social Measurement, Historical and Critical (1984).