Social Influence Given (Partially) Deliberate Matching: Career Imprints in the Creation of Academic Entrepreneurs
Executive Summary — How do people select partners for relationships? Most relationships arise from a matching process in which individuals pair on a limited number of high-priority dimensions. Although people often match on just a few attributes, it may be that some set of additional characteristics, which was not considered when a choice was made to develop the relationship, results in the social transmission of attitudes and behaviors. For this reason, social matching is only "partially" deliberate. HBS professor Toby Stuart and coauthors observe this phenomenon in an analysis of the origins and consequences of the matching of postdoctoral biomedical scientists to their faculty advisers. This work shows the imprints of postdoctoral advisers on the subsequent choices of the scientists-in-training who travel through their laboratories. The researchers' findings contribute to a burgeoning literature on the interface between academic and commercial science. Key concepts include:
- The fact that matching is only partially deliberate clearly opens avenues for the unforeseen transmission of attitudes and behaviors.
- In certain circumstances, the attributes to which we are unexpectedly exposed can matter. Particularly when these exposures take place in the context of relationships with long durations or ones in which there are notable status or experience differentials between partners, chance exposures can fundamentally change individuals' points of view.
- In long running, asymmetric relationships (such as those between protégés and advisers), the length of interaction provides ample opportunity for the standard pathways of influence to take hold. And when these experiences occur in the process of professional development as seen in this study, they may result in turning points that reorient actors' career trajectories.
- Such partially deliberate matching may permeate the sociology of the economy, as many social relationships in market contexts arise from a limited set of economic imperatives, but subsequently become pipelines for social influence.
Actors often match with associates on a small set of dimensions that matter most for the particular relationship at hand. In so doing, they are exposed to unanticipated social influences because counterparts have more interests, attitudes, and preferences than would-be associates considered when they first chose to pair. This implies that some apparent social influences (those tied to the rationales for forming the relationship) are endogenous to the matching process, while others (those that are incidental to the formation of the relationship) may be conditionally exogenous, thus enabling causal estimation of peer effects. We illustrate this idea in a new dataset tracking the training and professional activities of academic biomedical scientists. In qualitative and quantitative analyses, we show that scientists match to their postdoctoral mentors based on two dominant factors, geography and scientific focus. They then adopt their advisers' orientations toward commercial science as evidenced by the transmission of patenting behavior, but they do not match on this dimension. We demonstrate this in two-stage models that adjust for the endogeneity of the matching process, using a modification of propensity score estimation and a sample selection correction with valid exclusion restrictions. Furthermore, we draw on qualitative accounts of the matching process recorded in oral histories of the career choices of the scientists in our data. All three methods-qualitative description, propensity score estimators, and those that tackle selection on unobservable factors-are potential approaches to establishing evidence of social influence in partially endogenous networks, and they may be especially persuasive in combination. 47 pages.