We consider a model of the innovative environment where there is a distinction between ideas for R

We investigate optimal rewards in an R&D model where substitute ideas for innovation arrive to random recipients at random times. By foregoing investment in a current idea, society as a whole preserves an option to invest in a better idea for the same market niche, but with delay. Because successive ideas may occur to different people, there is a conflict between private and social optimality. We investigate the optimal policy when the social planner learns over time about the arrival rate of ideas, and when private recipients of ideas can bank their ideas for future use. We argue that private incentives to create socially valuable options can be achieved by giving higher rewards where "ideas are scarce."

We investigate rewards to R&D in a model where substitute ideas for innovation arrive to random recipients at random times. By foregoing investment in a current idea, society as a whole preserves an option to invest in a better idea for the same market niche, but with delay. Because successive ideas may occur to different people, there is a conflict between private and social optimality. We characterize the welfare-maximizing reward structure when the social planner learns over time about the arrival rate of ideas, and when private recipients of ideas can bank their ideas for future use. We argue that private incentives to create socially valuable options can be achieved by giving higher rewards where "ideas are scarce."

We consider a model of the innovative environment where there is a distinction between ideas for R&D investments and the investments themselves. We investigate the optimal reward policy and how it depends on whether ideas are scarce or obvious. By foregoing investment in a current idea, society as a whole preserves an option to invest in a better idea for the same market niche, but with delay. Because successive ideas may occur to di¤erent people, there is a con‡ict between private and social optimality. We argue that private incentives to create socially valuable options can be achieved by giving higher rewards where "ideas are scarce." We then explore how rewards should be structured when the value of an innovation comes from its applications, and ideas for the innovation may be more or less scarce than ideas for the applications.