This paper performs a comparison of two well known approaches for modelling R&D spillovers associated with investment in green technology, namely D'Aspremont-Jacquemin and Kamien-Muller-Zang. We show that there is little qualitative difference between the models in terms of total surplus...

We examine the use of subsidies to R&D in a mixed and a private duopoly market. We show that the socially optimal R&D subsidy is increasing in the degree of spillovers but it is lower in the private duopoly. The optimal R&D subsidy leads to an increase in total R&D and production, however, it...