Time Magazine features a story on how the evidence says the death penalty deters crime. I know: given that our legal system is radically slanted in favor of the accused, and given that the average time between sentencing and execution is 12 years, it’s a wonder there is any deterrent value. Yet studies show there is.
“Science does really draw a conclusion. It did. There is no question about it,” said Naci Mocan, an economics professor at the University of Colorado at Denver. “The conclusion is there is a deterrent effect.”
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?”
Note that Naci Mocan opposes the death penalty, yet admits his research shows a deterrent effect.
Notice this graph that illustrates a remarkable trend: as executions go up, murders go down. The lines don’t exactly shadow each other (but then, there is no swift execution of justice, either), but the trend is completely unmistakable.
Note that flat line of executions for the first few years of the graph came after the U.S. Supreme Court ban on capital punishment from 1972-1976.
From the article, here are some of the findings on the death penalty and deterrence:
— 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.
This last point is specifically interesting. Justice should be swift, to be fair to both the guilty and to those who await justice. An average of twelve years to execute a tried and convicted murderer spits in the face of justice. And as this shows, it weakens the deterrent effect. If the convicted murderer was executed within a year of being found guilty, cause and effect would be much more closely tied together…and would save more lives.
There are a number of articles here on the deterrence effect of capital punishment.
The death penalty would be good for society even if there were no deterrent effect; it forever removes the danger to society from someone who has demonstrated disregard for human life. It also demonstrates the value we place on human life, in that we require the ultimate penalty for the wrongful taking of human life. And it provides as close as we can come to justice for the one whose life was taken, and the loved ones who were robbed of that person’s life.