R&D competition and endogenous spillovers

The paper examines firms' choices between innovation and imitation in duopoly. We show that in the unique equilibrium asymmetric firms choose the same level of expenditure on imitation and the same ratio of innovative cost reduction to output. We evaluate the marginal contribution of innovation and imitation expenditure by small and large firms to consumer surplus and welfare, and discuss the desirability of differentiated R&D subsidies on innovation and imitation in terms of R&D tax rebates.