The question how mergers affect innovation has gained prominence in a number of recent merger cases. Accounting for the likely effects of mergers on innovation is difficult for a number of reasons though. First of all, the relationship between market concentration and innovation is far from...

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 are...

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...

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...

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...

We analyze how consumer preferences for one-stop shopping affect the bargaining relationship between a retailer and its suppliers. One-stop shopping preferences create "demand complementarities" among otherwise independent products which lead to two opposing effects on upstream merger...

We analyze the welfare effects of structural remedies on merger activity in a Cournot oligopoly if the antitrust agency applies a consumer surplus standard. We derive conditions such that otherwise price-increasing mergers become externality-free by the use of remedial divestitures. In this...

We re-examine the common wisdom that cross-border mergers are the most effective merger strategy for firms facing powerful unions. In contrast, we obtain a domestic merger outcome whenever firms are sufficiently heterogeneous (in terms of productive efficiency and product differentiation). A...

We analyze horizontal mergers when the acquirer holds a passive partial ownership stake (PPO) in the target firm prior to the merger. We show that a PPO reduces the minimal synergy level necessary to make a merger beneficial for consumers. It follows that an antitrust authority ignoring existing...