The intersection of antitrust and intellectual property circumscribes two century-long debates. The first pertains to questions about how antitrust law and intellectual property law interact, and the second pertains to questions about how parties can exploit property rights, including intellectual property rights, to exclude competitors. This iBrief finesses these questions and turns to practical considerations about how innovation and intellectual property can impinge antitrust enforcement. This iBrief develops two propositions. First, although collaborative research and development has often been and remains unwittingly misunderstood, what is understood about it is consistent with the long- standing observation that antitrust has rarely i...