Patent citations

Interesting bit of the day: if you look at granted patents and calculate the age of the patents that the given patent cites and calculate averages, it appears that the selection of companies affects the value quite a bit. In my case the aggregate patents of about 120 companies involved in either high-tech/electronics and/or automobiles shows that on average newer patents are cited than in the case of all the patents. The timeframe has been the patents from 1976 to 2010. Diagram below, blue bars are the first group and green is the group with all patents.