GMU Economist Alex Tabarrok writes:
Today I am in Florida giving a seminar to a group of Federal judges on the law and economics of Federalism and Crime. One of the surprising things that I discovered in my research is that cities, counties, and even most states can legally banish criminals from their borders. I say most states because, for example, the Georgia state constitution makes banishment illegal. Georgia judges, however, have found a way around the law they have imposed “158-county” banishment. (If you guessed that Georgia has 159 counties give yourself two points.)
Banishment is a particulary noteworthy example of a negative spillover – banishment benefits the state doing the banishing but only at the expense of other states. I will suggest to the Federal judges, therefore, that state banishment should be illegal.
As readers of this blog know, I am generally very supportive of federalism and decentralization. In this case, however, there is a strong argument for federal government intervention to prevent banishment, just as in cases where state governments dump pollution onto the land or waterways of neighboring states. By “banishing” criminals, state governments save themselves the cost of imprisoning them and also ensure that the cost of any future crimes these individuals commit (as well as the cost of punishing any such future crimes) will fall on other states. Indeed, banishment may actually reduce state government incentives to combat crime, because some of the costs of crime can be exported to their neighbors by banishing the criminals.
Some of Alex’s commenters argue that banishment should be retained because it is a relatively cheap and convenient way of punishing some types of criminals. This may be true, to some extent. But there are many other forms of punishment that cost much less than prison, yet do not have the perverse incentives created by banishment. Fines and community service are just two of many examples.
UPDATE: This post by Corey Yung of the Sex Crimes Blog provides evidence that interstate banishment may not be as common as Alex suggests.