Various patent indicators, such as number of citations, technology-cycle-time (TCT), number of claims, renewal status have been used to measure the value of patents with respect to economic value through competitive advantage a company patent holding company gains by holding legal rights to sale of the described technology. Another use of patent indicators attempts to gain insight into the emerging innovation landscape or “technology lifecycle”. Analysis of knowledge stock demonstrated by a group of patents can forecast potential novel technologies which will hold advantages over existing ones.
A patent’s forward citations are references to it received by a later filed patent as opposed to a backward citation which are references listed on a patent grant (or application) itself. The use of forward citations as a positive measure of a patents importance has been reviewed numerous times in academic literature.
The more (forward) citations a firm’s patents receive, the more influential its patents are for future technology, and the higher the assumed economic value of a firm’s patent stock.
However, forward citations have been found to only uncover a small portion of patent value information (Gambardella, 2008)(Bessen, 2008). Perhaps this is due to the ambiguous purpose of citations themselves. Most patent offices do not declare an explicit reason for citing another patent. In the European Patent Office (EPO), however, all forward citations are not equal, but rather may be classified by patent examiners as “blocking citations” which are references to previous art that may limit the scope of the patent that contains the reference. This inherently increases the strength and enforceability of the referenced patent. Unfortunately, the USPTO does not classify patent citations in any way.
Still, finding patents which have accumulated a disproportionate number of forward citations within a short period of time can give insight into an overall technology forecasting strategy.
Here we will investigate using forward citations of very new patents (patents that have been granted within the past 3 years) to uncover novel technologies and also describe some potential limitations of this approach. — TO BE CONTINUED —