Sir Thomas More: Honorary Economist

Apparently there is nothing new under the sun. George Stigler, one of the University of Chicago’s all-time great economists, introduced the phrase “marginal deterrence” to economists in a 1970 research paper. The idea behind marginal deterrence is that you want to set penalties such that, even if you can’t commit the criminal from carrying out a crime, he still has incentives to shift his criminal behavior toward less socially costly crimes.
Stigler’s idea wasn’t completely new. I believe the Italian criminologist Cesare Beccaria was writing about it back in the 1700’s, around the time of Adam Smith. So Stigler’s contribution was 200 years late, because at least among economists the idea had been lost.
My former student Emily Feldman informs me now that even Beccaria was a few hundred years too late. Back in 1516, Sir Thomas More already understood the concept. He writes in book one of Utopia:

And surely there is no one who doesn’t know how absurd and even dangerous for society it is to punish theft and murder alike. If the thief realizes that theft by itself carries the same peril as murder, that thought alone will encourage him to kill the victim whom otherwise he would only have robbed. Apart from the fact that he is in no greater danger if he is caught, murder is safer, since he conceals both crimes by killing the witness. Thus while we strive to terrify thieves with extreme cruelty, we really urge them to kill the innocent.

Hats off to Emily for this remarkable discovery.