The Death Penalty Works

Studies show that the death penalty is in fact a deterrent to crime:

A 2003 study he co-authored, and a 2006 study that re-examined the data, found that each execution results in five fewer homicides, and commuting a death sentence means five more homicides. "The results are robust, they don't really go away," he said. "I oppose the death penalty. But my results show that the death penalty (deters) — what am I going to do, hide them?"

Statistical studies like his are among a dozen papers since 2001 that capital punishment has deterrent effects. They all explore the same basic theory — if the cost of something (be it the purchase of an apple or the act of killing someone) becomes too high, people will change their behavior (forego apples or shy from murder).

To explore the question, they look at executions and homicides, by year and by state or county, trying to tease out the impact of the death penalty on homicides by accounting for other factors, such as unemployment data and per capita income, the probabilities of arrest and conviction, and more.

Among the conclusions:

• 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.

In 2005, there were 16,692 cases of murder and nonnegligent manslaughter nationally. There were 60 executions.

I don't think it really takes studies to figure this out, but I can guarantee you that every time there's a high profile execution, a lot of people have second thoughts about getting into situations that might make them eligible for death row. How many gang members in LA started rethinking their life after Stanley "Tookie" Williams got the needle?