Excerpt] Economists and academic administrators have long been concerned with issues of faculty productivity. For example, sets of studies have addressed whether faculty research productivity is related to faculty salaries, whether gender differences in faculty salaries remain after one controls for research productivity, and whether a negative association between faculty salary and seniority at an institution is due to universities having monopsony power or due to declining faculty research productivity with seniority.
To take another example, concern that the ending of mandatory retirement, which became effective for tenured faculty in January 1994, would lead to an aging nonproductive faculty has led other researchers to examine how faculty research and teaching productivity, the latter measured by undergraduate student evaluations, have varied over the life cycle. More recently, researchers studied whether declining research productivity is related to the acceptance of an offer for an early retirement incentive. Finally, other researchers have looked at how faculty research productivity varies across cohorts, finding that when a scientist enters the labor market has a substantial effect on his or her productivity over the life cycle and that more recently educated cohorts are not necessarily more productive than earlier cohorts. While some studies have looked at the implicit role that PhD student production has on the quality rankings of PhD programs, to our knowledge no studies have focused on how the distribution of PhD student supervisory responsibilities varies across faculty members at a university. Our study uses data on all PhDs produced during a 7-year period at Cornell University to illustrate how researchers can study whether the degree of inequality in PhD student supervision across faculty members within a broad field of study, varies across fields, as well as what the determinants are of differences in PhD student supervision responsibilities across individual faculty members within each broad field. Of particular concern to us, given the elimination of mandatory retirement, is how faculty members’ productivity in the supervision of PhD students varies over their life cycles.