Endogenous timing of R&D decisions with spillovers: Output versus research subsidies

This study considers an endogenous timing game of R&D decisions with research spillovers and compares the effects of output and research subsidies. We show that the simultaneous-move (sequential-move) game is an equilibrium if the spillover rate is low (high) under an output subsidy while this equilibrium is socially beneficial if the spillover rate is high or low enough. Under a research subsidy, however, the simultaneous-move game is a unique equilibrium regardless of the spillover rate, which is always socially beneficial. We also show that an output subsidy in the simultaneous-move game provides higher (lower) social welfare than a research subsidy if the spillover rate is low (high). Finally, we provide the robustness of our findings and some policy-relevant discussions.