Studies say death penalty deters crime

There are a few interesting studies that were recently talked about in an AP story on capital punishment as a deterrent (click here to read the full article). Here are excerpts from the article:

- Each execution deters an average of 18 murders, according to a 2003 nationwide study by professors at Emory University. (Other studies have estimated the deterred murders per execution at three, five and 14).

- The Illinois moratorium on executions in 2000 led to 150 additional homicides over four years following, according to a 2006 study by professors at the University of Houston.

- Speeding up executions would strengthen the deterrent effect. For every 2.75 years cut from time spent on death row, one murder would be prevented, according to a 2004 study by an Emory University professor.

There wasn't a link to the actual studies themselves, so I do not know exactly how these studies were carried out. For instance, did it take into account the economic background's (or difference in economic background) affect on the convicted? Or the change in economic conditions in a given area? The ratio of those who were convicted versus those found innocent? To tell you the truth, I am wondering how they conducted their information gathering techniques. I mean, are they taking the word of convicted murderers or potential murderers?

Regardless, I think these studies are an interesting starting point for a discussion on capital punishment.