Capital is the operative word

This Freakonomics article suggests the death penalty has negligible effect on crime. This is a direct rebuttal to an this AP article. I've read both and have to take the side of the Freakonomics guys... you can make up your own mind.
I have to ask: How is killing someone any different than keeping them alive but incarcerated for the rest of their life? I don't think it matters if the death penalty has an effect on crime... for me, not being able to exist in society for the rest of my life is the same thing as death. Based on some famous quotes from the forefathers... I think they'd agree ("Give me liberty or give me death" et al).

Capital punishment in it's current state should be justified or otherwise based on cost to the innocent taxpayer. For me it's simple, if it's cheaper to euthanize (that word sounds too nice)... if it's cheaper to the taxpayers to exterminate these criminals, that's what should be done.

Based on expected life span and aging-associated health care costs, there should be a point where a person is just too old to get the death penalty...simple because it's costs to much to kill them...but what if they want it (I don't know what the suicide rates are like in prison)?

Texas just legalized death penalty for repeat child rapists. Should the death penalty be broadened? Since I don't believe it's a deterrent, I look at economic factors first.

All of this is assuming the male is guilty (women comprise 1.7% of death row inmates) Of course, that depends on the debatable abilities of out judicial system. So take this post with a grain of salt... because Orenthal Simpson knows the system is flawed (you guys heard about the Juice's "here's how I would have done it" book, right?).