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...

We analyze market dynamics under Bertrand duopoly competition in industries with network effects and consumer switching costs. Consumers form installed bases, repeatedly buy the products, and differ with respect to their switching costs. Depending on the ratio of switching costs to network...

We analyze the role of consumer expectations in a Hotelling model of price competition when products exhibit network effects. Expectations can be strong (stubborn), weak (price-sensitive) or partially stubborn (a mix of weak and strong). As a rule, the price-sensitivity of demand declines when...

We analyze the efficiency defense in merger control. First, we show that the relationship between exogenous efficiency gains and social welfare can be non-monotone. Second, we consider both endogenous mergers and endogenous efficiencies and find that merger proposals are largely aligned with a...

Katz (1987), DeGraba (1990), and Yoshida (2000) have formulated theories that price discrimination bans in intermediary goods markets tend to have positive effects on allocative, dynamic and productive efficiency, respectively. We show that none of these results is robust vis-à-vis endogenous...

Given various recent antitrust investigations on the retail sector, we deal with uncovering demand systems substitution patterns for a particular market (diapers) to investigate the inter-format competition (supermarkets vs. discounters vs. drugstores). Using the uncovered demand system we...

We analyze Bertrand duopoly competition in markets with network effects and consumer switching costs. Depending on the ratio of switching costs to network effects, our model generates four different market patterns: monopolization and market sharing which can be either monotone or alternating. A...