Jonathan Rauch applies commons theory in an interesting way, in his latest article in Slate. (David Friedman made a similar argument a few days ago.) Basically, he argues that the problem with spam is that our inboxes (and attention) constitute a commons that spammers are overusing and despoiling. The solution? Require people to pay to send you e-mail– i.e., make use of your commons of attention. Hmmm….