Adblockers. They’re all the rage in discussions about the future of news organizations. This post on Medium by Dave Pell is one more restatement of the positive externalities generated by news organizations. While it is eloquent, it has no suggestion of how to deal with the problem. That’s because the problem of externalities is a genuinely hard one for our market-based economic organization (and way of thinking). Activities that generate positive externalities (and by extension public goods) are constantly under-provided and are likely to continue to be under-provided for the foreseeable future.