> A 1993 study by the Office of
>Technology Assessment found that two-thirds of all drug patents fell
>into this "copycat" category, meaning that they did not involve
>qualitatively new treatments for diseases.
I wonder how many of the copy cat patents are usused but kept on the books of the same company that owns the original so to better guarantee a better monopoly position? Maybe this is a rather small additional problem to the many that Baker has skillfully analyzed.
Yours, Rakesh