Are Markups Too High? Competition, Strategic Innovation, and Industry Dynamics

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, productivity growth, and the labor share are in decline. We develop a unified framework to explore the underlying economic mechanisms driving these changes, and the implications for economic growth and social welfare. The model combines a detailed oligopolistic competition model featuring endogenous entry and exit with a new Schumpeterian growth model. Within each industry, there are an endogenously determined number of superstars that compete a la Cournot and a continuum of small firms which collectively constitute a competitive fringe. Firms dynamically choose their innovation strategy, cognizant of other firms' choices. The model is consistent with the changes in the macroeconomic aggregates, and it replicates the observed hump-shaped relationship between innovation and competition within and across industries. We estimate the model to disentangle the effects of separate mechanisms on the structural transition, which yields striking results: (1) While the increase in the average markup causes a significant static welfare loss, this loss is overshadowed by the dynamic welfare gains from increased innovation in response to higher profit opportunities. (2) The decline in productivity growth is largely driven by the increasing costs of innovation, i.e. ideas are getting harder to find