Gypsies' informal institutions

Peter Leeson, the economics of pirates guy, has a new paper on gypsies:

Gypsies believe the lower half of the human body is invisibly polluted, that supernatural de…lement is physically contagious, and that non-Gypsies are spiritually toxic. I argue that Gypsies use these beliefs, which on the surface regulate their invisible world, to regulate their visible one. They use superstition to create and enforce law and order. Gypsies do this in three ways. First, they make worldly crimes supernatural ones, leveraging fear of the latter to prevent the former. Second, they marshal the beliefthat spiritual pollution is contagious to incentivize collective punishment of antisocial behavior. Third, they recruit the belief that non-Gypsies are supernatural cesspools to augment such punishment. Gypsies use superstition to substitute for traditional institutions of law and order. Their bizarre belief system is an efficient institutional response to the constraints they face on their choice of mechanisms of social control.