We study the impact of a General Purpose Technology that changes the cost structure turning fixed costs into variable ones in most sectors. A major recent example is cloud computing, whose adoption allows firms to avoid large up-front costs in IT and to rent computing capability online. We study...

I analyze the role of leadership in multi-sided markets as online advertising. Search and display advertising are better characterized by (respectively) quantity and price competition. A platform that reached dominance in search may have an incentive to limit services to consumers to be...

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...

I characterize microfounded endogenous market structures with Bertrand and Cournot competition and perform welfare analysis generalizing the Mankiw-Whinston condition for excess entry. The impact of market leaders on welfare is reconsidered, with a number of policy implications about strategic...

I characterize microfounded endogenous market structures with Bertrand and Cournot competition and perform welfare analysis generalizing the Mankiw-Whinston condition for excess entry. The impact of market leaders on welfare is reconsidered, with a number of policy implications about strategic...

This article provides an overview of recent progress in the theory of market structure, of the role of market leaders and the scope of industrial policy, presents new results through simple examples of quantity competition, price competition and competition for the market and develops new...

This article derives antitrust implications for markets where entry can be regarded as endogenous (contrary to most analysis within the post-Chicago tradition). Many applications concern issues of abuse of dominance. Endogenous entry requires a wide revision of our understanding of the role of...

Most market structures are neither perfectly or monopolistically competitive: they are characterized by a small number of large firms engaged in strategic interactions in their production and investment decisions. Yet, most of our economic theories are still based on a simplified world where...

A marketplace such as Amazon hosts a variety of products by third party sellers and acts as a first party or private label retailer. Assuming an advantage of Amazon in logistics and of sellers in marketing, we investigate whether entry by Amazon is excessive from the point of view of consumers...

I study a merger between producers of complement inputs facing entry of superior inputs, with investment by the incumbents in deterministic cost reduction and by the entrants in probabilistic innovation, and competition in prices. The merger is profitable by solving Cournot complementarity...