A mandate for open access to your publications is necessary

Empiric data from within the open access movement shows, that self archiving only works if an institutional open access mandate is in place. Obviously, this is not just a problem unique to open access but to other fields where compliance to procedures which evidently do have great advantages.

Food security:
"This isn’t simply a matter of caving in to industry pressure. The Bush administration won’t issue food safety regulations even when the private sector wants them. The president of the United Fresh Produce Association says that the industry’s problems “can’t be solved without strong mandatory federal regulations”: without such regulations, scrupulous growers and processors risk being undercut by competitors more willing to cut corners on food safety. Yet the administration refuses to do more than issue nonbinding guidelines."
Paul Krugman, New York Times, May 21, 2007