Changes

In 2015 there were 629,647 patent applications. Assuming history is anything to go by, around 80% will be eventually granted. Patents are valid for 20 years from application, providing renewal fees are paid at 3½, 7½, and 11½ years. Scotchmer (1999) reports that half of all patents are not renewed past 10 years. It currently takes the patent office more than 2 years, down from more than 3 years before the America Invents Act, to process a patent application. Applicants can request that undue processing time be added back to their patent terms. There are other factors, like terminal disclaimers and being found invalid or unenforceable by courts, which affect patent terms. A conservative estimate of mean patent term is 10 years from application. We will therefore use the 2.5m patents granted from 2006 to 2015 as a proxy for the number of active patents.

== Patent Trade ==