<< Am I the only
one who thinks that this was written to "prove" that the death
penalty doesn't have a deterrent effect? As if you could set up
a hypothesis that goes "Say it had a deterrent effect; then, in
the places where they have it, you should see lower rates of
homicide. If you don't see that, there's no deterrent!"
What lousy logic! >>
Um. Why exactly is the logic lousy? On the surface, it looks like Mill's methods od co-variation and difference, fundamental to science. Now you might think that the study didn't take account of all the relevant variables, in which case there might be something to the objection. But not because it compared states with and without the death penalty.
Also, what's wrong with being interested in the result of your study, as long as it's a good study?
It would be surprising if the death penalty had a deterrent effect. It's handed out freakishly and is still very rare. It is handed out for the worst crimes, those that havea n element of horror and insanity that suggest the absence of rational calculation that might take long term consequences into account.
However, people do not support the death penalty because they believe it might deter crimes. They support it for retributivist and often for unconsciously racist reasons. Even if it were proved that the death penalty did not deter crimes, or even that it tended to cause them, I think the support for the death penalty would not drop much if at all.
--jks