Closure and matching payoffs from college majors

Abstract This article examines the undergraduate major as a closure mechanism in occupations among college graduates, using the American Community Surveys. We measure the college major density of occupations, termed “major specialization”, finding that greater major specialization of an occupation is associated with higher earnings, over and above previously identified closure devices (licensure, unionization, and vertical educational credentialing), and college selectivity. We conclude that major specialization operates as a powerful earnings-boosting closure device within higher-educated labor markets. Additional analyses regarding premiums from individuals matching their own college major with their occupation’s typical major indicate comparatively small earnings payoffs. Hence, deviating from one’s occupation’s usual credential does not generate a substantial earnings penalty. Furthermore, payoffs from major-occupation matching have a ceiling: there is no further payoff above the average match level. These findings demonstrate how occupational closure theory helps explain the substantial earnings advantages of certain college majors in the labor force.