One of the pioneering works on endogenous market structures, by Tandon (1984), has extended the standard Cournot model with linear demand to endogenous entry and sunk R&D costs to show that the endogenous number of firms is independent from the size of the market. I generalize the model in many...

We develop a simple model of competition for the market that shows that, contrary to the Arrow view, endogenous entry threat in a market induces the average firm to invest less in R&D and the incumbent leader to invest more. We test these predictions with a Tobit model based on a unique dataset...