We study the gains from trade in a model with oligopolistic competition, heterogeneous firms and innovation, and provide a formula to decompose the mechanism. The new insight we provide is that market concentration can be a welfare-relevant feature of market power above and beyond markup...

The mixed-demand model allows for very flexible specification of what should be considered endogenous and exogenous in demand system estimation. This paper introduces a revealed preference framework to analyze the mixed-demand model. The proposed methods can be used to test whether observed data...