The influence of strategic patenting on companies' patent portfolios

This paper analyses whether strategic motives for patenting influence the characteristics of companies' patent portfolios. We use the number of citations and oppositions to represent these characteristics. The analysis is based on survey data from German companies, which are combined with EPO data covering applications from 1991 to 2000. We find clear evidence that the companies' patenting strategies are related to the characteristics of their patent portfolios. First, companies using patents in the traditional way to protect their technological knowledge base receive a higher number of forward citations for their patents. Second, the motive of offensive - but not of defensive - blocking is related to a higher incidence of oppositions, whereas companies using patents as bartering chips in collaborations receive fewer citations and fewer oppositions to their patents.