 After spending three years at the Brookings Institution in 1960–1963, he joined the University of Michigan and was promoted to full professor there in 1969.He was involved in the activities of the Institute for Social Research, the Center for Political Studies, and the Inter-university Consortium for Political and Social Research (ICPSR) at the University of Michigan and was one of the cofounders of ICPSR in 1963.He has been a professor in the Department of Political Science at the University of California, Santa Barbara since 1982.