[pizza_boy]

In economics a cost or benefit that is difficult to charge for is known as an externality. The pleasant smell of food might be a positive externality; second hand smoke a negative.

Ronald Coase (who also produced The Nature of the Firm) did the seminal work here. It turns out that in cases where it is difficult to assign property rights government intervention is often the best way to address externalities.

Readers of the essay may benefit from a footnote mentioning these basic economic principles.