That debate is now raging, not between traditional conservative and liberal politians or citizens, but between members of the liberal academia.

According to roughly a dozen recent studies, executions save lives. For each inmate put to death, the studies say, 3 to 18 murders are prevented.

The effect is most pronounced, according to some studies, in Texas and other states that execute condemned inmates relatively often and relatively quickly.

The studies, performed by economists in the past decade, compare the number of executions in different jurisdictions with homicide rates over time — while trying to eliminate the effects of crime rates, conviction rates and other factors — and say that murder rates tend to fall as executions rise. One influential study looked at 3,054 counties over two decades.

What is telling is that the data comes from those that are mostly liberal and personally opposed to the death penalty:

“I personally am opposed to the death penalty, but my research shows that there is a deterrent effect.” – H. Naci Mocan, an economist at Louisiana State University

“The evidence on whether it has a significant deterrent effect seems sufficiently plausible that the moral issue becomes a difficult one. I did shift from being against the death penalty to thinking that if it has a significant deterrent effect it’s probably justified.” – Cass R. Sunstein, a law professor at the University of Chicago

“I am definitely against the death penalty on lots of different grounds, but I do believe that people respond to incentives.” – Joanna M. Shepherd, a law professor at Emory

I’m not one who is wildly supportive of the death penalty. I have often said that I would easily concede doing away with capital punishment, if we would also do away with abortion. There is the hugely troubling issue of innocents being executed.

I also see the benefits of it as described by this research. I also believe it promotes the value of human life in an odd way. Human life should have such a high value that the only appropriate response to taking a life in a heinous manner is for the murder to forfeit their own life. To not punish in the severest possible way those that kill, is to affirm their apparent belief that human life which was taken is not valuable.

It will be interesting to see how this debate progresses, especially among the academics that rarely find themselves in agreement with conservatives and in opposition to their liberal colleagues.