Opportunities and benefits as determinants of the direction of scientific research.

Scientific research and private-sector technological innovation differ in objectives, constraints, and organizational forms. Scientific research may thus not be driven by the direct practical benefit to others in the way that private-sector innovation is. Alternatively, some - yet largely unexplored - mechanisms drive the direction of scientific research to respond to the expected public benefit. We test these two competing hypotheses of scientific research. This is important because any coherent specification of what constitutes the socially optimal allocation of research requires that scientists take the public practical benefit of their work into account in setting their agenda. We examine whether the composition of medical research responds to changes in disease prevalence, while accounting for the quality of available research opportunities. We match biomedical publications data with disease prevalence data and develop new methods for estimating the quality of research opportunities from textual information and structural productivity parameters.