We present a model with firms selling (homogeneous) products in two imperfectly segmented markets (a "high-demand" and a "low-demand" market). Buyers are mobile but restricted by transportation costs, so that imperfect arbitrage occurs when prices differ in both markets. We show that equilibria...

This paper sheds new light on the role of communication for cartel formation. Using machine learning to evaluate free-form chat communication among firms in a laboratory experiment, we identify typical communication patterns for both explicit cartel formation and indirect attempts to collude...

Boone (2008a) proposes a new competition measure based on Relative Profit Differences (RPD) with superior theoretical properties. However, the empirical applicability and robust-ness of the Boone-Indicator is still unknown. This paper aims to address that question. Using a rich, newly built,...

The experimental literature on antitrust enforcement provides robust evidence that communication plays an important role for the formation and stability of cartels. We extend these studies through a design that distinguishes between innocuous communication and communication about a cartel,...

Cartels can severely harm social welfare. Competition authorities introduced leniency rules to destabilize existing cartels and hinder the formation of new ones. Empirically, it is difficult to judge the success of these measures because functioning cartels are unobservable. Existing...

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...

Since 2010, Google, Apple, Facebook, Amazon, and Microsoft (GAFAM) have acquired more than 400 companies. Competition authorities did not scrutinize most of these transactions and blocked none. This raised concerns that GAFAM acquisitions target potential competitors yet fly under the radar of...

Previous work has shown that state-level antitrust enforcement activity may have impacts on entry and relocation behavior by U.S. firms. Significant state-level antitrust activity may be an indicator of a perceived adverse business environment and it is found to deter establishment entry,...

The paper deals with the competitive effects of price guarantees in a spatial duopoly where consumers can search for lower prices but have to incur hassle costs if they want to claim a price guarantee. It is shown that symmetric equilibria with and without price guarantees exist but price...

We investigate patterns in common ownership networks between firms that are active in the US pharmaceutical industry for the period 2004-2014. Our main findings are that "brand firms" - i.e. firms that have R&D capabilities and launch new drugs - exhibit relatively dense common ownership...