Michael Noel, Mar 14, 2011
Every year, the Federal Trade Commission(“FTC”)and the Antitrust Division of the Department of Justice (“DOJ”) are notified of thousands of mergers. Investigating which mergers are likely to have anticompetitive effects is a difficult, data-intensive, and resource-consuming task. Screens are necessary to target the truly problematic mergers and economize on scarce agency resources.
The agencies have historically relied in part upon a screen for unilateral effects based on the market shares of the merging firms. The 1997 merger guidelines state that, in concentrated industries, if the new merged firm would attain a market share of at least 35 percent the merger would be presumptively anticompetitive. The specific figure has since been dropped in the 2010 guidelines.
As has long been noted by economists, market share screens rely on the inherently difficult and artificial exercise of defining a relevant market from which to construct market shares. Market definition exercises must make a discrete “in or out” decision for each product from what is generally a continuum of substitute products, and market shares are sensitive to where this cutoff is drawn.
Recently, Joseph Farrell and Carl Shapiro (hereafter “FS”) introduced a new screen known as Upward Price Pressure (“UPP”) to flag potential unilateral effects. The screen requires as inputs estimates of diversion ratios, markups, and post-merger cost efficiency expectations.
On theoretic gro