Those conclusions are so outrageously off base.
Deterrent effect cannot be gauged that way. That's like trying to prove the existence of God mathematically; it's not even within the same realm of reasoning. And if you notice the only people who seem to agree with the findings of those studies are the people who carried them out.
In other news, 40% of Americans say they would not be able to serve on a jury and condemn somebody to death for moral reasons, while 60% say that they support the death penalty.
http://news.yahoo.com/s/nm/20070609/...thpenalty_dc_1
Also, I'm closing this thread, as it's been dug up more than enough as it is.