Actually the last advantage is very convincing, especially in the technology industry. The equilibrium R&D investment level depends in a very complicated way o

Actually the last advantage is very convincing, especially in the technology industry. The equilibrium R&D investment level depends in a very complicated way on the relationship between your market share at any point and the entire history of your investment. I won't be surprised if that equilibrium level goes up as IP protection period shortens. Of course, there is no objective way to decide what the socially optimal level of R&D investment is in the first place. I guess we can just assume that the higher the better, as long as the economy still produces some food :)