Mike Linksvayer has some interesting things to say about public goods and rent seeking (Public Goods Rent Seeking):

Copyright is (should be) the textbook case of wildly overestimating the public goods problem while ignoring rent seeking problems (NB “how can an artist make a full time living doing only art” is not a public goods problem). Witness massive production of art where expected profit from sales of copies and licensing is nil, both outside the content industry and where restrictions on copying are not enforced. Consider who benefits from perpetual copyright — not the public. [links, emphasis in original]