Otis Dudley Duncan (December 2, 1921 in Nocona, Texas – November 16, 2004, in Santa Barbara, California) was an American sociologist and statistician.
His key scholarly contributions include the introduction of path analysis to sociology; the measurement of occupational socioeconomic standing with an index (Duncan Socioeconomic Index); the study of intergenerational occupational mobility; the spatial analysis of residential patterns; the application and advancement of log-linear models and Rasch models for categorical social science data; and a landmark treatise on social measurement (Duncan 1984).
Using survey data and statistical techniques, it showed how an important sociological topic could be analyzed effectively and rigorously with appropriate quantitative methods.
In 2000 he joined his local Humanist Society which led him to publish new work on the prevalence of creationism, tolerance of atheists, support for euthanasia and other such issues.
Duncan was an elected member of both the United States National Academy of Sciences and the American Philosophical Society.