Since the 1970s, there have been significant changes in firm dynamics within and across industries in the US. Industries are increasingly dominated by a small number of large firms ("superstars"). Markups, market concentration, profits, and R&D spending are increasing, whereas business dynamism,...

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...

Firms use both innovation and advertising to increase their profits, markups, and market shares. While they serve the same purpose from the firms' perspective, their broader implications vary substantially. In this paper, we study the interaction between these two intangible inputs and analyze...