Increasing globalization of business schools makes the hiring of research active faculty from abroad a more frequent practice; however, existing systems of business school industry stratification were predominantly created to help select candidates with a background from the same country. In this paper we discuss possible social categorization biases due to underdeveloped stratification in a global labor market and the consequences of the biased decision-making for the careers of academic researchers. We further explore the drivers of research productivity among sub-populations of European business school faculty with different patterns of international mobility. We use a sample of 360 tenured faculty members from 20 European business schools in 10 countries. These schools were randomly selected from the 50 most research intensive schools based on publication in the top 150 ISI listed business and management journals over 2007-2012. Our findings show that social closure in academic hiring is reinforced by an underdeveloped stratification of research-intensive employers in a global labor market. One manifestation of this closure is the trend for academic inbreeding in emerging scientific systems, that is, in countries where the field of organizational sciences has only recently started to develop according to international standards. The findings of this study have implications for academic researchers who consider international mobility and for hiring committees of business schools with an international profile.