Marketing and strategy researchers have often studied how organizations navigate multiple identities in relation to category spanning but extant literature pays less attention to understanding how individuals do so. Moreover, current econometric approaches only scratch the surface with respect to addressing the impact of multiple identities in professional settings. As a model domain to study labor market returns when individuals have more than one identity, we focus on interdisciplinary dissertators in the United States since evidence shows clear uptrends in dissertators engaging multiple professional identities and unclear trends in their outcomes. Our novel estimation method leverages a two-step process to characterize salaries of interdisciplinary dissertators as functions of the identities (academic fields) they acquire as graduate students. We estimate a first-stage regression of log earnings for monodisciplinarians on field dummies and respondent characteristics. After capturing the estimated field coefficients, we then regress log earnings for interdisciplinarians on linear and non-linear functions of these coefficients. Our estimates robustly reject the hypothesis that interdisciplinarians receive a salary premium. We also find evidence that the academic market, but not other employment sectors, particularly compensates researchers based on their primary discipline, an outcome that challenges emphases on interdisciplinarity. While our findings for interdisciplinarians point to the primary identity holding predominant importance for doctoral graduates in the United States, our two-step method provides a framework for parsing and estimating the varied impacts of multiple identities across a wide range of contexts.

Institutional leaders have long championed interdisciplinary research; however, researchers have paid relatively little attention to the people responding to such calls and their subsequent career outcomes. With the benefit of two large datasets spanning from 1986 through 2016, we show that interdisciplinary dissertations have become consistently more common in recent years as institutional leaders have highlighted the value of boundary-spanning research for solving important and emergent problems. With the benefit of survey data from a near-complete population of all dissertators in the US starting in 2001 through 2016, we observe a consistent upward trend in interdisciplinary dissertations. Unfortunately, we show that these interdisciplinary dissertators have experienced a comparably persistent penalty when considering salaries for their first year after earning the PhD. We also show that among interdisciplinary dissertators, individuals in lower-paying fields tend to earn more when choosing distantly related topic-combinations whereas researchers in higher-paying fields tend to be most rewarded for staying within relatively narrow disciplinary silos.