Deterrence

“The death penalty is certainly not an effective law enforcement tool. Effective law enforcement and crime prevention requires precious resources that are being wasted on this ineffective and broken program. In times of fiscal crisis the programs that fail to achieve their own goals should be the first to go.” Ken Jones, 33-year veteran of Illinois’ Cook County Police Department

Studies find no meaningful evidence that the use of the death penalty deters crime.

The National Research Council of the National Academies based on a review of more than three decades of research concluded that studies claiming a deterrent effect on murder rates from the death penalty are fundamentally flawed and should not be used when making policy decisions. (2012)

Consider the following:

• A Death Penalty Information (DPI) study of 30 years of FBI Uniform Crime Report Homicide data showed that the South had the highest murder rate and accounts for over 80% of the executions in the nation. That region also accounts for more law enforcement officers killed than any other region in the last 15 years. The Northeast, which has less than 1% of executions, again had the lowest murder rate.
• In New Jersey the murder rate dropped two years in a row after the death penalty was repealed, with Camden, NJ, reaching its lowest level of violent crime since 1969.
• The U.S. with the death penalty has a much higher murder rate than countries in Europe which do not have the death penalty
• A 2009 study found 88% of the nation’s top criminologists believe the death penalty is not a deterrent. (“Do Executions Lower Homicide Rates? The Views of Leading Criminologists,” Northwestern University School of Law’s Journal of Criminal Law and Criminology by Professor Michael Radelet and Traci Lacock, June 2009).
• Even police officers do not believe the death penalty is an effective deterrent. Police chiefs ranked the death penalty last among effective ways to reduce violent crime in a 2009 survey. A full 99% said that changes such as reducing drug abuse or improving the economy were more important than the death penalty in reducing violent crime.

RESEARCHERS FIND FLAWS IN STUDIES CLAIMING DETERRENT EFFECT

In an article entitled, “The Death Penalty: No Evidence for Deterrence,” John Donohue and Justin Wolfers examined recent statistical studies that claimed to show a deterrent effect from the death penalty. The authors conclude that the estimates claiming that the death penalty saves numerous lives “are simply not credible.” In fact, the authors state that using the same data and proper methodology could lead to the exact opposite conclusion: that is, that the death penalty actually increases the number of murders. The authors state: “We show that with the most minor tweaking of the [research] instruments, one can get estimates ranging from 429 lives saved per execution to 86 lives lost. These numbers are outside the bounds of credibility.”

The authors conclude that the evidence of deterrence is far too weak to rely on as a justification for the death penalty:

The view that the death penalty deters is still the product of belief, not evidence. The reason for this is simple: over the past half century the U.S. has not experimented enough with capital punishment policy to permit strong conclusions. Even complex econometrics cannot sidestep this basic fact. The data are simply too noisy, and the conclusions from any study are too fragile. On balance, the evidence suggests that the death penalty may increase the murder rate although it remains possible that the death penalty may decrease it. If capital punishment does decrease the murder rate, any decrease is likely small.

John Donohue is a professor at Yale Law School and a Research Associate at the National Bureau of Economic Research. Justin Wolfers is a professor at the Wharton School of Business and a Research Affiliate at the National Bureau of Economic Research. (The Economists’ Voice, April 2006).

The overwhelming conclusion is that, despite the numerous studies on the deterrent effect of the death penalty, their findings have either been inconclusive or conflicting with each other. As summarized in a report released in 2012 by the National Research Council, “research to date on the effect of capital punishment on homicide rates is not useful in determining whether the death penalty increases, decreases, or has no effect on these rates.'”