This paper presents results from a multiple-year project concerned with the involvement of foreign (non-U.S.) entities in U.S. patent litigation. A comparison of data from 2004 and 2009 that cover 5,407 patent cases filed in U.S. federal district courts in those two years evidences an increase in the number of cases involving foreign defendants, and thus an increasing potential for cross-border enforcement problems. With this basic finding the research supports the proposition advanced by a number of intellectual property scholars in the U.S. and abroad that rules need to be established to facilitate a smooth process for recognition and enforcement of foreign judgments in intellectual property cases. The research fills a significant gap in the existing literature, which has relied so far on only isolated individual cases to illustrate cross-border enforcement problems; comprehensive empirical evidence has not existed to show a growing need for improved rules for recognition and enforcement. In addition to providing this missing evidence the paper uses data concerning the involvement of foreign defendants to reveal remarkable facts about the changing landscape of patent litigation in the U.S.
Marketa Trimble, When Foreigners Infringe Patents: An Empirical Look at the Involvement of Foreign Defendants in Patent Litigation in the U.S., Santa Clara Computer & High Technology L. J., Vol. 27, No. 3, (2011)