Now available — Externality and taboo: Resolving the Judaic pig puzzle

My article with Peter Leeson and Nicholas Snow is now available online at Rationality and Society. The article makes a simple point — there is a rational choice explanation for the emergence and enforcement of a taboo on pigs with Judaism. That explanation is rooted in the idea that pigs are trespassers that can damage higher-value properties of non-pig owners. The pig is an externality when raised the way it was during the Iron Age (and in Judea). A taboo is a way to define property rights and to enforce them. The reason is that those who suffered trespass were also the lowest-cost managers of the externality (or, phrased differently, they were those who were best able to maximize wealth net of transaction costs). The abstract is below and you can email me for the full paper in case its gated:

Judaic law famously bans pigs. For millennia, scholars have wondered why. This paper uses the economics of property rights to resolve the puzzle. We argue that the Judaic pig ban was an instrument for internalizing swine externalities. Free ranging pigs in search of sustenance trespass on agricultural landowners’ property, wreaking destruction. Activities that foster such pigs thus create negative externalities that can cripple agricultural economies. When the expected cost of swine externalities becomes large, internalization becomes worthwhile: lawmakers with a vested interest in the agricultural economy ban activities that foster free ranging pigs. That is what transpired in ancient Judah, where lawmakers were priests whose livelihoods depended on agriculture, where all swine ranged freely, and where the expected cost of swine externalities surged during the late Iron Age. Lawmakers invoked God to enjoin involvement with pigs because a supernatural injunction was cheaper to enforce than a natural one: in a land of faithful Hebrews, Yahweh’s swine prohibition enforced itself. The Judaic pig ban’s features are consistent with pig bans recently adopted by US states such as Montana, which everyone agrees are instruments for internalizing swine externalities.