$5 to Elsevier for a PDF of this paper. That made me look up the organization, the federal-sounding National Bureau of Economic Research. They're not feds at all, they're some private think-tank. It seems to me that "economic" think tanks are always tools of the crypto-fascist imperialistic elite, if you'll pardon the hyperbole. So, I'm not surprised by (a) the $5 fee, and (b) the finding that incumbents generate most innovation, which is kind of false to my experience, at least, and maybe false to common wisdom.