Dennis Crouch has published an excellent article on American patent applications data in Patently-O. Dennis has analysed 10,000 of the most recent patents "to see what's going on with pendency and other issues." He found the average time from filing to grant in the case of applications that were not based on a previous US filing to have been 3 years and 4 months and the average time from filing to grant in the case of applications based on a prior US filing to have been 2 years and 11 months. Applications based on foreign filings seemed to take the same amount of time regardless whether they were based on a previous filing or not.
It is interesting to compare the US Patent and Trademark Office's performance with that of our own. Some comparable data is available from "Facts and Figures 2004-2005" and some performance data can be checked from the Patent Office's Annual Report and Accounts for 2005 and 2006. Judging by the table on page 58 of the Annual Report which indicates that 93% of patents were granted within 2 1/2 years of request our boys and girls don't do too badly. Of course, they don't handle anything like the volume of the USPTO. I haven't checked the EPO's stats yet but I am not sure that I shall anything like as gratified when I do.
Anyway returning to Dennis Crouch, it is an excellent article in a first rate blog. Professional commitments and other matters have kept me from reading other peoples' blogs as well as writing my own over the last few months but Patently-O was one that I always read. If you are pressed for time, gentle readers, that is the very last one to miss.