The production of scientific ideas.

• Author: Azoulay, Pierre
• Position: Research Summaries

There is considerable evidence that the advancement of science influences productivity in the private sector of the economy. Thus, policymakers typically believe that public investments in science are important for long-run economic growth. But how do new scientific ideas come about? Apocryphal stories of Archimedes' eureka moment, or Newton's otherworldly contemplation interrupted by the fall of an apple, would have us believe that luck is an essential feature. Of course, if luck is all that is necessary to produce breakthroughs, then there is little room for scholarship on the subject. If, on the other hand, scientific knowledge production depends upon individuals, institutions, and incentives, then economic research should play an important role in increasing our understanding in this area.

While the pioneering work of Zvi Griliches, the founding director of the NBER's Productivity Program, set the stage for hundreds of subsequent empirical studies examining the diffusion of various technologies, comparatively little work has focused on the creation of the original technologies in the first place. This dearth of applied research on idea creation has not been for lack of interest but rather principally because of data limitations. As recently as 15 years ago, very little data were available to systematically study the scientific enterprise. Today, economists have at their disposal vast quantities of new data that allow them to link mentors and trainees, collaborators, and intellectual peers to characterize the production team. The data on papers, patents, and citations enable one to trace out the impact of individual bits of knowledge as they are incorporated into the research activities of other research teams, as well as within private sector firms. Together with methodological advances in the analysis of quasi-experimental data, we have begun to credibly characterize this production process, the conditions under which scientists collaborate to create new knowledge, and the benefits that follow.

One important theme that has emerged from the recent literature is the notion that an increased burden of knowledge because of an ever-expanding scientific frontier has led to greater scientific specialization, longer training periods, and to an increased propensity to collaborate. (1) This realization has cast a pall over the potential for ideas-based growth, because it implies that innovation is becoming more difficult over time. (2) Ultimately, whether this pessimism is warranted is an empirical question, which has led us to explore in more detail the impacts of interactions among scientists for the pace of scientific advance, and whether these interactions occur because of geographic proximity, shared intellectual interests, or social connections.

The Impact of Superstar Scientists

While the most important scientific work is much more likely to be produced as part of a collaboration than was the case only 40 years ago, (3) our own work suggests that the central members of these teams -- whom we call " superstars"-- continue to play an important role in shaping the rate and direction of scientific advance. Over the past ten years, we have gathered biographical information for a sample of 12,000 elite, academic life scientists, and combined these with precise measures of...