Entry Deterrence, Concentration, and Merger Policy

In merger enforcement, entry is considered to be a factor that potentially can mitigate otherwise anti-competitive effects of a merger. The current framework for entry analysis evaluates whether potential entrants are likely to have the incentives and ability to enter the industry under the conditions of elevated profitability that are created by an anti-competitive merger. Missing from entry analysis is the notion that incumbent firms may proactively deter entry and how such incumbent incentives may change as a result of a merger. By modeling entry as the outcome of a game between incumbents and potential entrants, we show that a merger can reduce the likelihood of entry even at elevated profit levels by increasing incumbent incentives to invest in entry deterrence. The paper has two policy implications for merger enforcement: First, a merger that is benign by traditional measures may nonetheless have the effect of reducing future entry—entry that would have made the market more competitive relative to status quo. Second, evidence of recent historical entry—which is an important criterion that is used to assess the likelihood of post-merger entry—may be of less evidentiary value than is considered under the current merger enforcement policy.