By ROBERT TANNER, AP National Writer
19 minutes ago
Anti-death penalty forces have gained momentum in the past few
years, with a moratorium in Illinois, court disputes over lethal
injection in more than a half-dozen states and progress toward
outright abolishment in New Jersey.
The steady drumbeat of DNA exonerations pointing out flaws in the
justice system has weighed against capital punishment. The moral
opposition is loud, too, echoed in Europe and the rest of the
industrialized world, where all but a few countries banned
executions years ago.
What gets little notice, however, is a series of academic studies
over the last half-dozen years that claim to settle a once hotly
debated argument whether the death penalty acts as a deterrent to
murder. The analyses say yes. They count between three and 18 lives
that would be saved by the execution of each convicted
killer.
The reports have horrified death penalty opponents and several
scientists, who vigorously question the data and its
implications.
So far, the studies have had little impact on public policy. New
Jersey's commission on the death penalty this year dismissed the
body of knowledge on deterrence as "inconclusive."
But the ferocious argument in academic circles could eventually
spread to a wider audience, as it has in the past.
"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?"
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.
The studies' conclusions drew a philosophical response from a
well-known liberal law professor, University of Chicago's Cass
Sunstein. A critic of the death penalty, in 2005 he co-authored a
paper titled "Is capital punishment morally required?"
"If it's the case that executing murderers prevents the execution
of innocents by murderers, then the moral evaluation is not
simple," he told The Associated Press. "Abolitionists or others,
like me, who are skeptical about the death penalty haven't given
adequate consideration to the possibility that innocent life is
saved by the death penalty."
Sunstein said that moral questions aside, the data needs more
study.
Critics of the findings have been vociferous.
Some claim that the pro-deterrent studies made profound mistakes in
their methodology, so their results are untrustworthy. Another
critic argues that the studies wrongly count all homicides, rather
than just those homicides where a conviction could bring the death
penalty. And several argue that there are simply too few executions
each year in the United States to make a judgment.
"We just don't have enough data to say anything," said Justin
Wolfers, an economist at the Wharton School of Business who last
year co-authored a sweeping critique of several studies, and said
they were "flimsy" and appeared in "second-tier journals."
"This isn't left vs. right. This is a nerdy statistician saying
it's too hard to tell," Wolfers said. "Within the advocacy
community and legal scholars who are not as statistically adept,
they will tell you it's still an open question. Among the small
number of economists at leading universities whose bread and butter
is statistical analysis, the argument is finished."
Several authors of the pro-deterrent reports said they welcome
criticism in the interests of science, but said their work is being
attacked by opponents of capital punishment for their findings, not
their flaws.
"Instead of people sitting down and saying 'let's see what the data
shows,' it's people sitting down and saying 'let's show this is
wrong,'" said Paul Rubin, an economist and co-author of an Emory
University study. "Some scientists are out seeking the truth, and
some of them have a position they would like to defend."
The latest arguments replay a 1970s debate that had an impact far
beyond academic circles.
Then, economist Isaac Ehrlich had also concluded that executions
deterred future crimes. His 1975 report was the subject of
mainstream news articles and public debate, and was cited in papers
before the U.S. Supreme Court arguing for a reversal of the court's
1972 suspension of executions. (The court, in 1976, reinstated the
death penalty.)
Ultimately, a panel was set up by the National Academy of Sciences
which decided that Ehrlich's conclusions were flawed. But the new
pro-deterrent studies haven't gotten that kind of scrutiny.
At least not yet. The academic debate, and the larger national
argument about the death penalty itself with questions about
racial and economic disparities in its implementation shows no
signs of fading away.
Steven Shavell, a professor of law and economics at Harvard Law
School and co-editor-in-chief of the American Law and Economics
Review, said in an e-mail exchange that his journal intends to
publish several articles on the statistical studies on deterrence
in an upcoming issue.
http://news.yahoo.com/s/ap/20070611/ap_on_re_us/death_penalty_deterrence
