Renewal Study of European Patents: A Three-country Comparison
This paper utilizes the renewal records of the EPO (European Patent Office) patents and estimates the patent value distributions in Germany, France and the U.K. An interesting finding, according to the author, is that the EPO patent holders are found to be much more willing to invest resources on finding new commercialization strategies in order to exploit their patented idea than the national patent holders in Pakes (1986).
Link
ftp://ftp1.economics.smu.edu/WorkingPapers/2005/Deng/renew3nations_july2005.pdf