The Dynamic Effects of Antitrust Policy on Growth and Welfare

To shed light on the dynamic effects of antitrust policy on growth and welfare, we develop and estimate the first general equilibrium model with Schumpeterian innovation, oligopolistic product market competition, and endogenous M&A decisions. The estimated model reveals that: (1) Existing policies generate gains in growth and welfare. (2) Strengthening antitrust enforcement could deliver substantially higher gains. (3) The dynamic long-run effects of antitrust policy on social welfare are an order of magnitude larger than the static gains from higher allocative efficiency in production. (4) Current HHI-based antitrust rules leave the majority of anticompetitive acquisitions undetected, highlighting the need for alternative guidelines. Overall, our results suggest that the long-run impact on innovation policy and aggregate productivity growth should receive much higher consideration in the design of antitrust policies