Harhoff, Dietmar; von Graevenitz, Georg; Wagner, Stefan - 2013
benefit from revocation of a patent and when firms are caught up in patent thickets. Using data on opposition against patents … at the European Patent Office we show that opposition decreases in fields in which many others profit from patent … revocations. Moreover, in fields with a large number of mutually blocking patents the incidence of opposition is sharply reduced …