There are tons of empirical studies showing the effects, good and bad, of patent systems using historical as well as more recent data. For instance studies of h

There are tons of empirical studies showing the effects, good and bad, of patent systems using historical as well as more recent data. For instance studies of historical fairs have shown that the introduction of a patent system greatly increased the rate of innovation in fields where other protection was not previously available. On the other hand there are studies showing that patent tickets in some industries caused slowdowns in progress. There is significant evidence of various benefits and costs. The problem is, these pros and cons are not directly comparable so nobody can say one outweighs the other.