For a long time I've argued that patents make no sense from a societal viewpoint when the time of independent discovery is less than the length of the patent and where alternative means of disseminating information for benefit exists (such as Open Source, Scientific Journals etc) - for more see here and here.
Patents can act as a spur for innovation but also as a choke-hold. As commoditisation of communication, open source and other factors have accelerated the rate and diffusion of innovation then the length of term is becoming even more problematic.
So today, whilst casually researching another issue, I came across this beautiful paper from Rufus Pollock on optimal copyright length.
