2.3. Guideline 3: Mergers Can Violate the Law When They Increase the Risk of Coordination

The Agencies determine that a merger may substantially lessen competition when it meaningfully increases the risk of coordination among the remaining firms in a relevant market or makes existing coordination more stable or effective. [Endnote 19] Firms can coordinate across any or all dimensions of competition, such as price, product features, customers, wages, benefits, or geography. Coordination among rivals lessens competition whether it occurs explicitly—through collusive agreements between competitors not to compete or to compete less—or tacitly, through observation and response to rivals. Because tacit coordination often cannot be addressed under Section 1 of the Sherman Act, the Agencies vigorously enforce Section 7 of the Clayton Act to prevent market structures conducive to such coordination.

Tacit coordination can lessen competition even when it does not rise to the level of an agreement and would not itself violate the law. For example, in a concentrated market a firm may forego or soften an aggressive competitive action because it anticipates rivals responding in kind. This harmful behavior is more common the more concentrated markets become, as it is easier to predict the reactions of rivals when there are fewer of them.

To assess the extent to which a merger may increase the likelihood, stability, or effectiveness of coordination, the Agencies often consider three primary factors and several secondary factors. The Agencies may consider additional factors depending on the market.

2.3.A. Primary Factors

The Agencies may conclude that post-merger market conditions are susceptible to coordinated interaction and that the merger materially increases the risk of coordination if any of the three primary factors are present.

Highly Concentrated Market

By reducing the number of firms in a market, a merger increases the risk of coordination. The fewer the number of competitively meaningful rivals prior to the merger, the greater the likelihood that merging two competitors will facilitate coordination. Markets that are highly concentrated after a merger that significantly increases concentration (see Guideline 1) are presumptively susceptible to coordination. If merging parties assert that a highly concentrated market is not susceptible to coordination, the Agencies will assess this rebuttal evidence using the framework described below. Where a market is not highly concentrated, the Agencies may still consider other risk factors.

Prior Actual or Attempted Attempts to Coordinate

Evidence that firms representing a substantial share in the relevant market appear to have previously engaged in express or tacit coordination to lessen competition is highly informative as to the market’s susceptibility to coordination. Evidence of failed attempts at coordination in the relevant market suggest that successful coordination was not so difficult as to deter attempts, and a merger reducing the number of rivals may tend to make success more likely.

Elimination of a Maverick

A maverick is a firm with a disruptive presence in a market. The presence of a maverick, however, only reduces the risk of coordination so long as the maverick retains the disruptive incentives that drive its behavior. A merger that eliminates a maverick or significantly changes its incentives increases the susceptibility to coordination.

2.3.B. Secondary Factors

The Agencies also examine whether secondary factors demonstrate that a merger may meaningfully increase the risk of coordination, even absent the primary risk factors. Not all secondary factors must be present for a market to be susceptible to coordination.

Market Concentration

Even in markets that are not highly concentrated, coordination becomes more likely as concentration increases. The more concentrated a market, the more likely the Agencies are to conclude that the market structure suggests susceptibility to coordination.

Market Observability

A market is more susceptible to coordination if a firm’s behavior can be promptly and easily observed by its rivals. Rivals’ behavior is more easily observed when the terms offered to customers are readily discernible and relatively observable (that is, known to rivals).

Observability can refer to the ability to observe prices, terms, the identities of the firms serving particular customers, or any other competitive actions of other firms. Information exchange arrangements among market participants, such as public exchange of information through announcements or private exchanges through trade associations or publications, increase market observability. Regular monitoring of one another’s prices or customers can indicate that the terms offered to customers are relatively observable. Pricing algorithms, programmatic pricing software or services, and other analytical or surveillance tools that track or predict competitor prices or actions likewise can increase the observability of the market.

Competitive Responses

A market is more susceptible to coordination if a firm’s prospective competitive reward from attracting customers away from its rivals will be significantly diminished by its rivals’ likely responses. This is more likely to be the case the stronger and faster the responses from its rivals because such responses reduce the benefits of competing more aggressively. Some factors that increase the likelihood of strong or rapid responses by rivals include: (1) the market has few significant competitors, (2) products in the relevant market are relatively homogeneous, (3) customers find it relatively easy to switch between suppliers, (4) suppliers use algorithmic pricing, or (5) suppliers use meeting-competition clauses. The more predictable are rivals’ responses to strategic actions or changing competitive conditions, and the more interactions firms have across multiple markets, the greater the susceptibility to coordination.

Aligned Incentives

Removing a firm that has different incentives from most other firms in a market can increase the risk of coordination. For example, a firm with a small market share may have less incentive to coordinate because it has more to gain from winning new business than other firms. The same issue can arise when a merger more closely aligns one or both merging firms’ incentives with the other firms in the market. In some cases, incentives might be aligned or strengthened when firms compete with one another in multiple markets (“multi-market contact”). For example, firms might compete less aggressively in some markets in anticipation of reciprocity by rivals in other markets. The Agencies examine these and any other market realities that suggest aligned incentives increase susceptibility to coordination.

Profitability or Other Advantages of Coordination for Rivals

The Agencies regard coordinated interaction as more likely to occur when participants in the market stand to gain more from successful coordination. Coordination generally is more profitable or otherwise advantageous for the coordinating firms the less often customers substitute outside the market when firms offer worse terms.

Rebuttal Based on Structural Barriers to Coordination Unique to the Industry

When market structure evidence suggests that a merger may substantially lessen competition through coordination, the merging parties sometimes argue that anticompetitive coordination is nonetheless impossible due to structural market barriers to coordinating. The Agencies consider this rebuttal evidence using the framework in Section 3. In so doing, the Agencies consider whether structural market barriers to coordination are “so much greater in the [relevant] industry than in other industries that they rebut the normal presumption” of coordinated effects. [Endnote 20] In the Agencies’ experience, structural conditions that prevent coordination are exceedingly rare in the modern economy. For example, coordination is more difficult when firms are unable to observe rivals’ competitive offerings, but technological change has made this situation less common than in the past and reduced many traditional barriers or obstacles to observing the behavior of rivals in a market. The greater the level of concentration in the relevant market, the greater must be the structural barriers to coordination in order to show that no substantial lessening of competition is threatened.

[Endnote 19] See Brooke Grp. Ltd. v. Brown & Williamson Tobacco Corp., 509 U.S. 209, 229-30 (1993) (“In the § 7 context, it has long been settled that excessive concentration, and the oligopolistic price coordination it portends, may be the injury to competition the Act prohibits.”).

[Endnote 20] See H.J. Heinz Co., 246 F.3d at 724.