Unilateral Effects Analysis in Merger Review: Limits and Opportunities

29 Pages Posted: 24 Jan 2014 Last revised: 8 Apr 2014

See all articles by Malcolm B. Coate

Malcolm B. Coate

U.S. Federal Trade Commission (FTC)

Date Written: April 7, 2014


Many economists believe that unilateral effects analysis should dominate the merger review process for differentiated products. However, it is far from clear if these theoretical models are broadly applicable, as they impose monopoly-style entry assumptions that constrain the competitive process. By abstracting from the complexities of the market process, the standard unilateral effects analysis gives rise to tractable mathematical equilibriums. Of course, the equilibriums may not offer insights if the key assumptions are not valid.

This paper will explore the limits to and opportunities for unilateral effects analysis, using the Landes-Posner model of a dominant firm as an initial example, before expanding the discussion to Nash-Bertrand models of competition. These Lerner-based modeling structures are problematic, especially when the entry-related assumptions are not credible. Because economic models may remain applicable even when their assumptions are not valid, the discussion addresses various types of effects evidence that could confirm the predictions of a specific unilateral effects model. Court precedent is reviewed, with an emphasis on a current understanding of the structural presumption, along with the applicability of effects evidence to litigation. By focusing the analysis on facts, unilateral effects analysis serves to aid the merger review process.

Keywords: merger, antitrust, competition policy, guidelines, presumption, unilateral effects

JEL Classification: K21, L40

Suggested Citation

Coate, Malcolm B., Unilateral Effects Analysis in Merger Review: Limits and Opportunities (April 7, 2014). Available at SSRN: https://ssrn.com/abstract=2383476 or http://dx.doi.org/10.2139/ssrn.2383476

Malcolm B. Coate (Contact Author)

U.S. Federal Trade Commission (FTC) ( email )

601 Pennsylvania Avenue, NW
Washington, DC 20580
United States

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