Book Description

(cont.) I prove the existence of the equilibrium and show that the model's predictions are consistent with the aforementioned reduced form evidences. These results rely on two assumptions: the concavity of the profit function with respect to firm size and the constant returns to scale property of the R&D production function. The intuition is that, when profits are concave, the incentives for radical innovation diminishes as firm size increases. As a result, R&D intensity and firm growth also decrease. Next, I estimate the structural parameters of the model using Simulated Methods of Moments and use the results to conduct a policy experiment. Since firms in this model do not internalize the positive externalities that they generate on other firms, there is underinvestment in R&D, so that there is scope for policy action through size-dependent R&D subsidies. In conclusion of this policy experiment, the optimal size-dependent R&D subsidy policy does considerably better than optimal uniform (size-independent) policy. Moreover, supporting small firms is more growth-enhancing than subsidizing big firms. For a large range of values for the elasticity of substitution, the growth enhancing effect dominates the negative impact of public spending on initial consumption. Therefore, the optimal (welfare-maximizing) policy provides higher subsidies to smaller firms.