Two economists at Washington University, Michele Boldrin and David K. Levine, have recently published a book, Against Intellectual Monopoly, which asserts that the “current patent/copyright system discourages and prevents inventions from entering the marketplace. ”
Against Monopoly (a blog maintained by Professors Boldrin and Levine)
The book seems to be freely available online: http://www.dklevine.com/general/intellectual/againstfinal.htm