Antitrust authorities are particularly concerned with the dominant market position of tech giants such as Google, Facebook, and Amazon. These digital conglomerates are characterized by platform-based business models. However, despite their dominance, they are competing with each other to attract...

It is often argued that, first, the decision criterion of antitrust authorities should be total social welfare and that, second, mergers increasing the value of this criterion but ending with lower consumer surplus should be allowed in the name of efficiency gains realized by merging firms. This...

We explore the design of self-financing tax-subsidy schemes to solve hold-up problems in environmental regulation. The announcement of the tax rate seems to be preferable to solve hold-up problems with respect to the investment in environmental R&D. In contrast, only the announcement of the...

This paper analyzes pricing decisions and competition in network markets, assuming that groups of consumers can coordinate their choices when it is in their interest, if coordination does not require communication. It is shown that multiple asymmetric networks can coexist in equilibrium. A...

This paper analyzes pricing decisions and competition in network markets, assuming that groups of consumers can coordinate their choices when it is in their interest, if coordination does not require communication. It is shown that multiple asymmetric networks can coexist in equilibrium. A...

This paper assumes that groups of consumers in network markets can coordinate their choices when it is in their best interest to do so, and when coordination does not require communication. It is shown that multiple asymmetric networks can coexist in equilibrium if consumers have heterogeneous...

In standard Walrasian macro-finance models, pecuniary externalities due to fire sales lead to excessive borrowing and insufficient liquidity holdings. We investigate whether imperfect competition (Cournot) improves welfare through internalizing the externality and find that this is far from...

This paper analyzes pricing decisions and competition in network markets, assuming that groups of consumers can coordinate their choices when it is in their interest, if coordination does not require communication. It is shown that multiple asymmetric networks can coexist in equilibrium. A...

This paper assumes that groups of consumers in network markets can coordinate their choices when it is in their best interest to do so, and when coordination does not require communication. It is shown that multiple asymmetric networks can coexist in equilibrium if consumers have heterogeneous...

This paper studies the design of sin taxes when firms exercise market power. We outline an optimal tax framework that highlights how market power impacts the efficiency and redistributive properties of sin taxation, and quantify these effects in an application to sugar-sweetened beverage...