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Why Price Correlations Don't Define Antitrust Markets: On Econometric Algorithms For Market Definition, Jonathan Baker

Working Papers

This paper compares two econometric methods that have been proposed for market definition: price correlations and residual demand curve estimation. Econometric theory is used to demonstrate that price correlations among firms will likely contain little or no information relevant to defining antitrust markets, under the assumption that a hypothetical cartel facing a downward sloping residual demand curve constitutes an antitrust market (defined according to the DOJ Guidelines). Hence price correlation analyses are likely to have little value for antitrust market definition. In terms of the literature on empirical techniques for market definition, this paper shows that if the econometric market …