Perhaps no area of antitrust law reflects the different assumptions and philosophies of Chicago School and post-Chicago analysts more than monopolization and vertical restraints. Whereas the Chicago School sees little risk from exclusionary conduct, even by monopolists, a post-Chicago and other scholars recognize that raising rivals' costs can frequently be a profitable strategy for dominant firms, may well harm consumers and/or the competitive process. The AAI believes the U.S. agencies should take a more aggressive enforcement posture towards exclusionary conduct by dominant firms and renew antitrust's historic skepticism of durable monopolies and their predatory practices.