On Friday, June 14, Danielle Foley moderated a webinar discussion, “Proving But-for Entry Dates in Pharmaceutical Antitrust Litigation.” This discussion, sponsored by the ABA Antitrust Section Health Care and Pharmaceuticals Committee, focused on a question that often arises in pharmaceutical antitrust litigation: When would generic entry have occurred absent the accused conduct? In this program, a panel of experienced economists and attorneys discussed approaches to proving but-for entry dates. They illustrated the limitations of and issues with the economic models and evidence used to support and dispute earlier entry dates.