Posner and Becker have both come out in favour of capital punishment for murder. I reluctantly agree, but for somewhat different reasons.
There is mixed evidence that capital punishment deters murders (cited by Posner and Becker). Both Posner and Becker think this evidence is persuasive. Posner even restates the powerful neoclassical economics explanation for why capital punishment has a strong deterrent effect:
it is exceedingly rare for a defendant who has a choice to prefer being executed to being imprisoned for life.
My question: does anyone know the suicide rate for prisoners incarcerated for life? Does it depend on prison conditions? Does it depend on the types of cell-mates and fellow prisoners one must deal with? How does it compare with suicide rates for people of similar intelligence and background but not in prison?
I can think of many fates worse than death [an evening with a life insurance salesman? (cf Woody Allen)], and I can readily imagine that many? some? prisoners would prefer to take their own lives rather than be subjected to life in some prisons.
To the extent that this supposition makes sense, capital punishment might not have much of a deterrent effect. In fact, it might very well be a better deterrent to keep the criminals alive under horrid prison conditions.
So why do I reluctantly favour capital punishment? To put a polite term on it: retributive justice. Less politely, vengefulness. There are some criminals who commit crimes so heinous they don’t deserve to live (And this from a guy who was a long-time pacifist). If I thought we could punish them more by keeping them alive in horrid prison conditions, I would favour that option, but given all the bleeding-heart tendencies for prison reform, I know that ain’t gonna happen.
For more of my thoughts on cruel and unusal punishment, see this.