Duopoly firms engaged in a standard two-stage game of R&D and Cournot competition are caught in a prisoner's dilemma for their R&D decisions whenever spillover effects are low. This effect works to the advantage of consumers and society. This result provides an interesting perspective on the...

We consider the standard two-stage game of R&D and Cournot competition with ex ante identical firms but depart from the literature in assuming that R&D is characterized by mildly, instead of strongly, decreasing returns to scale. We establish that only extreme R&D levels are possible at...