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...

We analyze duopoly Bertrand competition under network effects. We consider both incompatible and compatible products. Our main result is that network effects create a fundamental conflict between the maximization of social welfare and consumer surplus whenever products are incompatible. While...

This paper investigates the strategic effect of bundling when a multi-product firm producing two complements faces competition in both markets. I consider a demand structure where both Cournot and Bertrand competition can be evaluated. Bundling is completely ineffective when firms compete in...

We revisit the relationships between competition and market outcomes in a Stackelberg oligopoly. Consider a differentiated oligopolistic market consisting of n leaders with different efficiencies and m followers. We show that the efficient leader's profit may increase with the number of...

This paper analyzes exclusionary conduct of platforms in two-sided markets. Motivated by recent antitrust cases against shopping centers introducing radius restrictions on their tenants, we provide a discussion of the likely positive and normative effects of exclusivity clauses, which prevent...

Competition is the backbone of U.S. economic policy. The U.S. Supreme Court observed, “The heart of our national economic policy long has been faith in the value of competition.” Competition advocacy is also thriving internationally. Promoting competition is broadly accepted as the best...

Local network externalities are present when the network externalities associated with entering a certain network depends not only on the total number of agents in the network, but on the identity of the agents in the network. We explore the consequences of local network externalities within a...

We analyze the likelihood of arms race behavior in markets with liquidity provision by HFTs. Liquidity providers (makers) and liquidity consumers (takers) make costly investments in monitoring speed. Competition among makers and takers induces arms race behavior. However, trade success...

This paper analyses a two-sided market in which two platforms compete against each other. One side, the advertisers, exerts a negative externality on the ther side, the users. It is shown that if platforms can charge advertisers only, a higher degree of competition for users can lead to higher...

Market power on each side of a multisided platform, whether in the form of increasing prices or decreasing quality, is constrained by the risk of losing sales on the other sides. That tends to weaken market power on each side and encourages platforms to keep prices lower and quality higher than...