Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Early entry has the advantage of higher revenues per unit of output early on. Late entry has the benefit of learning from the experience of earlier entrants, and hence lower production costs. The advantages are balanced off in a continuous-time, perfect-foresight equilibrium. Competition generates S-shaped diffusion, and staggered entry and exit. A monopolist will innovate less than a competitive industry, but the innovation that he does do, he will do sooner. Copyright 1989 by American Economic Association.