We study the causal impact of invalidating marginally valid patents during post-grant opposition at the European Patent Office on affected inventors' subsequent patenting. We exploit exogenous variation in invalidation by leveraging the participation of a patent's original examiner in the...

R&D expenditures of firms varies vastly between and within industries. In recent years a lot of theoretical and empirical studies attempted to explain the distribution of R&D expenditures. Four main factors repeatedly appeared in this literature: Firm size, market power, appropriability and...