On behalf of the merging parties, Brattle economists analyzed the competitive impact of Duke Energy’s acquisition of Piedmont Natural Gas for antitrust review by the Federal Trade Commission and “public interest” review by the North Carolina Utilities Commission. Our analysis examined the effect of the transaction on competition with respect to gas transportation and delivered gas in North Carolina and other areas, including allegations of potential “vertical” harm through partial foreclosure or the use of strategies to raise rivals’ costs.