This is one of the big reasons why there shouldn't be a death penalty.
It helps that in probably 80% of the cases there is no real doubt on the identity of the killer (not all cases are a suspense movie scenario). But I wonder if the reliability of courts is even higher that whatever that percentage is.
"In practice, it's more expensive than life-in-prison" doesn't do it for ya?
If the death penalty were reserved for use in cases that meet a higher standard -- say "guilty beyond any conceivable possibility of doubt" -- I wouldn't necessarily have a problem with it. To me, that's the difference between a Timothy McVeigh and a West Memphis Three. But I don't have any insight into how many cases would meet that criterion. It may be that the death penalty is simply not worth reserving as an option in those cases.
Regarding just the second number - deterrence - here's a claim that the death penalty deters, saving between 3 and 18 lives per execution depending on the study you choose (quite the spread, BTW...):
http://www.washingtonpost.com/wp-dyn/content/article/2007/06...
...But here's a claim that the death penalty doesn't deter (though they cite, not direct statistical evidence, but the opinion of criminologists and the fact that some places without a death penalty have lower murder rates than places with it; but maybe if I dug deeper I'd find something more direct):
http://www.deathpenaltyinfo.org/facts-about-deterrence-and-d...
Perhaps someone who've looked into it more deeply can weigh in; all I'm saying is that it matters what the answer is.
(My own intuition would be that people aren't deterred by the death penalty very much, because they count on not getting caught, instead of multiplying the penalty by the probability or some such. But I could be wrong. Also I'm open to the opinion that you shouldn't do some things to people regardless of potential benefits to society, for instance I'm pretty sure torture would deter more than the death penalty because it's a very vivid picture a potential criminal would have in their mind, but it's great that nobody thinks we should go there. I just don't think that the capital punishment is "cruel and unusual" that way.)
I could not disagree with you more! It should not matter how much total good it does if even one person is wrongly killed via the death penalty. It sounds like a logically sound thing until you find yourself being the one person society has decided to kill for the better good of the society.
That said, I understand the deterrent effect to be often assumed to be far greater than reality bears out, and I think the death penalty is quite a poor practice on balance for a host of reasons.
It's certainly true that threatening prosecutors with execution in the event of a wrongful execution would stop them from pursuing the death penalty in almost any case. The same is true of a threat of life in prison, and probably also true of substantially lesser sentences.
A rough translation (my French is rusty - been a decade or two): "The law is clear: Anyone who intentionally kills another will lose their head. Let the executioner do his duty." "This way, my friend" "And so, a good deed done" "I'm sorry, but anyone who intentionally kills another..."
(Idées Noires is fantastic and macabre. Franquin kept "letting" people who causes suffering for other people - or animals - die horrible deaths in his panels, often with a solid dose of poetic justice in between other things, and coupled with rather caustic political commentary. Unfortunately, AFAIK I don't think there is an English translation (one was in the works), but even with quite modest French they're relatively easy to understand (many of them don't have much or any text))
[1] http://www.franquin.com/in/album3_in.php - rightmost panel on the top.
I'll be sure to write, "if only the person that stabbed me in this dark alley had the deterrent of possibly being convicted and executed maybe I would still be alive" in blood before I lose consciousness or run out of blood.
The death penalty isn't about deterrence. It's about vengeance. At least to the family and friends of the victim.
Many in the US, for religious reasons, consider death to be the ultimate punishment. You know - "hell is that way".
But what if you don't believe in hell, or a judgement? Then death is an easy way out. Personally, I'd rather die than be thrown into a hole for 40 years.
So allow me to rephase: //I'd think that it matters how many innocent people are executed vs how many people believe the criminal will suffer in hell.
Either way, i agree.
Because they believe hell is more of a punishment. They'd rather see the criminal dead in hell, then sitting in a jail cell alive.
I just googled this and discovered there's a Christianity Stack Exchange site. Seems to be no strong consensus on exactly when you get to heaven.
The Emory study cited by that first article (http://cjlf.org/deathpenalty/DezRubShepDeterFinal.pdf) doesn't inspire me much. Show me an observational study which the researchers claim "eliminates the bias arising from unobserved heterogeneity", and I'll show you a study that was conducted by overconfident researchers who're overselling the strength of their evidence.
And no, after reading the paper I'm not personally convinced that they did deal with unobserved heterogeneity. I'm not even convinced that the authors fully understand what the unobserved heterogeneity problem's really about. They seem to think that it's something you can whisk away by just throwing a bunch of covariates at your data, which is not how it works. If they mentioned their conditional independence assumption, let alone attempted to defend it, I missed it.