(FORTUNE Magazine) – Your servant was recently browsing through Nexis, reading about the death penalty, not because this is his idea of a good time, honest, but because he was thinking of writing something about the interesting ambivalence of the American Civil Liberties Union in this area. The ACLU endlessly condemns the barbarism and cruelty it discerns in every imaginable method of execution. But it also condemns efforts put forward to make execution less cruel, e.g., the recent adoption of lethal injection, because painless killing makes the death penalty more ''acceptable.'' That is what we were planning to write about. What we ended up getting intrigued by was a thought that surfaced in a Chicago Tribune piece stumbled upon in the Nexis search. The thought: that in + a considerable number of cases, sentencing somebody to death probably increases his life expectancy. We first sniffed this astounding proposition in a May 1989 Chicago Tribune opinion piece by Stephen Chapman, and finally decided it has to be true. It is really quite logical when you think about it. For openers, very few individuals on death row actually get executed: only about 20 a year, from a population around 2,400. Those arriving on death row nowadays are increasingly apt to come from the violence-prone drug business. Nobody exactly knows the death rate in that business, but it figures to be a lot higher than 20/2,400 per year. In any case, Chapman quotes professor Arthur Alschuler of the University of Chicago law school as guessing that a drug dealer on death row has a longer life expectancy than one on the street. On the street, the dealer faces numerous characters just as depraved as he is. And has no ACLU to protect him.