Andy and April are using Ben’s things without his permission and it’s starting to bug him. The two negotiate for ways to remedy the externality.
The citizens of Pawnee drink from a water fountain by placing their whole mouth on the nozzle. Ann correctly points out the externality in the situation that by kissing one water fountain drinker, you’re kissing them all.
The pollution from the local factory creates a beautiful sunset, but it also gives people asthma.
Ron finds a typewriter out by the dumpster, but the noise of the machine bothers everyone in the office.
Ron describes how he shouldn’t have to follow government regulations about toxic chemicals because he’s the only one breathing the fumes.
Leslie tries to turn the pit into a public garden and allows citizens to plant whatever they chose in the garden. Someone decided to plant marijuana in the garden instead.