A New Taxonomy for Star Scientists: Three Essays

It is surprising that the prevailing performance taxonomy for scientists (Star versus Non-Star) focuses only on individual output and ignores social behavior since scholars often characterize innovation as a communal process. To address this deficiency, I expand the traditional taxonomy that focuses solely on productivity and add a second, social dimension to the taxonomy of scientists: helpfulness to others. Using a combination of academic paper citations and Impact Factor-weighted publications to measure scientist productivity as well as the receipt of academic paper acknowledgements to measure helpfulness, I classify scientists into four distinct categories of human capital quality: All-Stars, who have both high productivity and helpfulness; Lone Wolves, who have high productivity but average helpfulness; Mavens, who have average productivity but high helpfulness; and Non-Stars, who have both average productivity and helpfulness.The first study examines the impact of 415 immunologists on the performance of their coauthors. Looking at the change in quality-adjusted publishing output of an immunologist's coauthors after the immunologist's death, I find that the productivity of an All-Star's coauthors decreases on average by 35%, a Maven's coauthors by 30% on average, and a Lone Wolf's coauthors by 19%, all relative to the decrease in productivity of a Non-Star's coauthors. These findings suggest that our current conceptualization of star scientists, which solely focuses on individual productivity, is both incomplete and potentially misleading as Lone Wolves may be systematically overvalued and Mavens undervalued.The second study builds upon the first study's finding that Mavens have a large impact on the performance of their coauthors. Using salary disclosures from 2008 at the University of California, I examine the extent to which each star type is compensated differently. While Mavens have a larger impact on the performance of their coauthors than Lone Wolves, Mavens are compensated less, providing preliminary evidence that these performance effects are spillovers.The third study examines the likelihood of an immunologist's mobility as a function of his observable and unobservable human capital. The greater a scientist's productivity (observable to the market), the greater his inter-institution mobility, while the greater a scientist's helpfulness (unobservable to the market), the lower his inter-institution mobility.