Samuel Little, a man who confessed killing 93 women over four decades, died in a California prison in late December” (Hannah Knowles, “Deadliest Serial Killer in American History Dies at 80, with Police Still Searching for his Victims,” Washington Post, December 30, 2020). He illustrated in a horrible way what Nobel-winning economist Gary Becker taught us: criminals are rational in the sense that they respond to incentives; those who are not rational don’t stay long on the market.

Becker was awarded the 1992 Nobel Prize in economics for “having extended the domain of economic theory to aspects of human behavior which had previously been dealt with—if at all—by other social science disciplines such as sociology, demography and criminology.” The higher the cost for a given benefit, the fewer crimes will be committed. (Recall that benefits are subjective.)

Ex ante, the expected cost of a crime from the criminal’s viewpoint is given by his likely punishment times the probability of being caught and condemned (assuming he is risk neutral). Of course, he will do anything that can be done at low cost to reduce the second factor in his expected punishment. For Little, an efficient criminal, this meant killing only women who were less likely to be missed by somebody and whose deaths were thus less likely to be successfully investigated. His victims were prostitutes, drug addicts, homeless women… He has not been the only criminal pervert in history to do so: Jack the Ripper comes to mind. The Post writes:

 He boasted to investigators of killing with impunity and avoiding “people who would be immediately missed.”

In a terrible sentence, which also reminds us of the obstacles (including occupational licensure and zoning) that American governments have raised against black flourishing in America, Little, who is himself a black man, explained to the Washington Post:

I’m not going to go over there into the White neighborhood and pick out a little teenage girl.