This paper develops a theory of patent portfolios in which firms accumulate an enormous amount of related patents in … infringe on other firms ́patent portfolios. We investigate how litigation incentives for the holders of patent portfolios … impact the incentives to introduce new products and draw welfare implications. We also consider a patent portfolio …

creates a shock for the patent holder but also its competitors who cite that patent: invalidation wipes out portfolio … synergies and the necessity to have defensive patents. This paper shows that Federal Circuit patent litigations affect the … invalidated patent. This observation supports that many patents are renewed for defensive purposes. The portfolio size also …

In an effort to decompose and adjust patent sales prices for patent portfolio valuation, this study analyzes patent … July 2011 did not fundamentally change the pricing of patent portfolio, and patent market has not been in bubble. Also …, while NPEs play an active role in patent sale market, there is no difference in pricing between the transactions with at …