With some delay, I attach David Spector's insightful presentation on collective dominance under the ECMR (which was presented at the last lunch talk of the GCLC). David's slides confirm that the standard of proof is set extremely high. However, David suggests that quantitative techniques can be useful to substantiate a prediction of coordinated effects post merger. And there, I get a bit lost, as I have found many contradictory statements of economists on the issue. Many have affirmed that coordination can only be evidenced quantitatively in a narrow set of circumstances. Your input would be most appreciated.