The referenced AEI/Brookings study has been scrubbed from the web. I have captured it on my own site at this link —

Here is a summary of the research that corroborates my own informal field study. The weight of the evidence shows that the sparing but periodic employment of the death penalty for the category of the most deliberate murders does have a net deterrent effect, i.e., it saves many more lives than it costs. In my opinion, the strong moral bias against executions shared widely in the academy and the relevant research communities has operated to bury data that demonstrates a death penalty deterrence effect.

“Journal of Applied Economics.”

4/01, Vol 33, N 5, p569 — p576, “Execution Moratorium Is No Holiday For Homicides; Execution and deterrence: a quasi-controlled group experiment.” Professors Dale O. Cloninger and Roberto Marchesini University of Houston. [Professor Cloninger (, Professor Marchesini (]

“The (Texas) execution hiatus (in 1996), therefore, appears to have spared few, if any, condemned prisoners while the citizens of Texas experienced a net 90 (to as many as 150) additional innocent lives lost to homicide. Politicians contemplating moratoriums may wish to consider the possibility that a seemingly innocuous moratorium on executions could very well come at a heavy cost.”

Professor Cloninger: “ . . . (Our recent) study is but another on a growing list of empirical work that finds evidence consistent with the deterrence hypothesis. These studies as a whole provide robust evidence — evidence obtained from a variety of different models, data sets and methodologies that yield the same conclusion. It is the cumulative effect of these studies that causes any neutral observer to pause.”

Emory University Paper:

“Does Capital Punishment Have a Deterrent Effect: New Evidence from Post-moratorium Panel Data”, Dezhbakhsh, Rubin ( and Shepherd (, January 2001. Located at January 2001.

Emory University Economics Department Chairman Hashem Dezhbakhsh and Emory Professors Paul Rubin and Joanna Shepherd: “Our results suggest that capital punishment has a strong deterrent effect. An increase in any of the probabilities — arrest, sentencing or execution — tends to reduce the crime rate. In particular, each execution results, on average, in eighteen fewer murders — with a margin of error of plus or minus 10.” Their data base used nationwide data from 3,054 US counties from 1977-1996.

University of Colorado (Denver) Paper:

“Pardons, Executions and Homicide”, H. Naci Mocan ( and R. Kaj Gottings (, October 2001, located at

University of Colorado (Denver) Economics Department Chairman Naci Mocan and Graduate Assistant R. Kaj Gottings found “a statistically significant relationship between executions, pardons and homicide. Specifically each additional execution reduces homicides by 5 to 6, and three additional pardons (commutations) generate 1 to 1.5 additional murders.” Their “data set contains detailed information on the entire 6,143 death sentences between 1977 and 1997.

Overview of U.S. Homicide Trends:

“Long term trends, Homicide Victimization, 1950-99”, Bureau of Justice Statistics, Source: FBI, Uniform Crime Reports, 1950-99, (ii) Crime in the United States — 2000, Section II — Crime Index Offenses Reported, “Murder and non negligent homicide”, FBI, Uniform Crime Reports, “Number of persons executed in the United States, 1930-2001”, Key Facts at a Glance, Executions Bureau of Justice Statistics, Source: Capital Punishment 2000, December 2001 at

Between June 1967 and January 1976, there was an effective national moratorium on executions (see the California experience below for more details). From 1966-1980, basically for the entire moratorium, U.S. criminal homicides jumped from 11,040 to 23,040, and the murder rate increased from 5.6 to 10.2/100,000. During that quasi moratorium period, the US averaged only 1 execution every 3 years, with a maximum of two executions per year. After the moratorium: From 1995-2000 executions averaged 71 per year. The US murder rate dropped from a high of 10.2/100,000 in 1980 to 5.5/100,000 in 2000, a 46% decrease. For a population of 200 million, the net 4.7% increase in annual murders represents an additional 9,400 killings.

Analysis of California Homicide Trends:

Recent California Experience is strongly suggestive of a deterrent effect. Between 1930 (the first year for which we have reliable records) through 1976 there were 292 executions (3,859 in the US). In the period from 1967 to 1977 there was an informal California moratorium on death penalty cases, part of a nationwide trend. No one was executed during that period in the state, and very few in the U.S. at large.

In 1976 the US Supreme Court effectively overturned the death penalty laws for several states (including California) in Fuhrman vs. Georgia 408 US 153. The Fuhrman court invalidated unfettered discretion statutes for producing “arbitrary and capricious” results. Also in 1976, “guided discretion” statutes were upheld in Gregg vs. Georgia 428 US 153 and Proffitt vs. Florida 428 US 242. The same year, mandatory death statutes were disapproved in Woodson vs. N. Carolina 428 US 280 and Roberts vs. Louisiana 428 US 325.

California voters enacted a qualifying death penalty statute in 1976 by a lopsided majority, but Rose Bird was appointed Chief Justice in 1977. [At the time, I thought it was a good appointment.] From that year until her removal in 1986 by the voters (along with Justices Reynoso and Grodin), there was another effective death penalty moratorium.

The Bird court reversed 61 death cases. From 1967 through 1991 there were no California executions. During this period the murder rate increased from 6 murders per 100,000 people to 12.6 murders per 100,000.

No one was executed in California until the Harris execution in 1992. In the next ten years, hundreds of death penalty cases arrived on death row, and there were 11 executions. According to California Attorney General Bill Lockyer, violent crime declined between 1993 through 1999 by 34%. Between 1991 and 2000, the homicide rate fell 47%, from the 1992 high of 12.9 per 100,000 to 5.9 per 100,000 at the end of 1999.

I am well aware of the other studies and statistics that are cited to the effect that there is no conclusive evidence of deterrence. So what are we “realistic persuadables” to make of all this? Deterrence can be measured in a number of ways:

(a) anecdotally, i.e., by collecting statements of criminals who admit to have refrained from killing someone when the opportunity and motive coincided, citing fear of the death penalty;

(b) statistically, by measuring the increase (or decrease) of the homicide rate when the death penalty is suspended;

(c) statistically, by measuring the decrease (or increase) of the homicide rate when the death penalty is enforced.

To summarize our problem: No perfect controlled experiment has yet been designed on a significant scale to produce a precise measure of the deterrence effect of the death penalty because there are too many variables: How much is the penalty actually used? What is the street level perception of the death penalty’s use? What is the arrest rate? The clearance rate? What is the time lag between charge and execution? [The median stay on California’s death row is about 13 years, a product of widespread ambivalence about the death penalty within the justice system and its exploitation by death penalty opponents.] The major problem with the statistical approaches (b) and (c) above is that demographics and other population factors shift with time. For example, the release into a population of violent criminals can skew numbers in favor of a homicide rate increase, masking any deterrence effect. But the larger the sample, the more the deterrence effect tends to show itself. The US and California numbers are large enough to show the trends.

Social Cost Analysis

A social cost calculation is possible, based on the value of a human life in different circumstances. Here is the formula:

L = [D s] – [E p]

· L is the measure of the success of the death penalty in net valuable lives.

· D is the raw number of lives saved by deterrence.

· s is the value assigned each life saved by deterrence. [s=1 or whatever society chooses.]

· E is the raw number of executions in the time frame.

· p is the value assigned to the life of a murder perpetrator.[p = 1 or whatever society chooses.]

To solve for “L,” we multiply the number of lives saved by deterrence times the value “s.” From that number, we subtract the number of executions times the value “p.” L is a measure of the success of the death penalty in valuable lives.

In other words, whenever “L “is a positive number, net valuable lives are saved. If “p’ (the value of the life of the killer) is set at zero, then the death penalty always saves net lives unless “D s” (value of lives saved by deterrence) is zero. This never happens (unless we perversely place s, the value of a single life saved, at zero), because we can always find examples of criminals who were deterred.

Some would have us assign the life of a convicted killer exactly the same value that of a saved life. [I think this is fairly perverse. When “p” and ‘s ‘each = 1, we have a moral equivalence between killer and victim.] But even in that calculation, the death penalty saves valuable lives because a tiny deterrent effect produces a net savings of human life whenever “E” is a small number. Only a minuscule percentage of all homicide convicts are actually executed.

For example, at a rate of 6 homicides per 100,000, a jurisdiction with a population of 30 million people would suffer 1,800 homicides in a year. Let’s assume 16 are executed in a given year (which is more than the total number California executed in the last decade). If only 2% additional homicides are deterred that year because of the possibility of the death penalty, 36 innocent lives will have been saved, a net savings of 20 lives even if we were to perversely assign the same value to the life of each murder victim and murderer.

Only if the value of “p” is grossly exaggerated can that calculation outcome be changed. If effect, the true-believer death penalty opponents are assigning an infinite value to p, the life of the killer. This may or may not be good theology, but it is terrible public policy.

Let’s pick a more realistic number for p. Assume the value of the life of a convicted death eligible killer is reduced to p=.5, (a generous value considering the value most Californians would assign). If only 9 murders were deterred in the last hypothetical, society would still be ahead. And when the reduced penal consequences to the would-be killers are taken into account (after all a murder deterred is one less killer, too), the societal balance sheet is not even close.

Whenever the value of the convicted killer’s life is reduced from p=1, a very, very weak deterrence effect, one measured by a handful of individual cases, always demonstrates a net social benefit.

But the real deterrence effect of the death penalty is undoubtedly stronger. The studies referenced and California’s recent experience are consistent with a large actual deterrence effect, one greater than the actual number of executions. Compare the moratorium period from 67 to 92, and the resumed execution period from 92 to the present day. There was a swing of 6 homicides per 100,000, a reduction in the murder rate attributable in whole or part to the resumption of the death penalty. Consider that an increase of 6 homicides per 100,000 to 12 per 100,000 is an increase of 1,800 homicides per year for a population of 30 million people. Those numbers strongly suggest a deterrence effect to large to mask or deny.

Deterring Violence-Prone Recidivists

Not all sub-populations are equally deterred. Criminally prone males do most murders. Educated people with a lot to lose (i.e., most death penalty opponents) are deterred from killing each other by a moral code, coupled with the prospect of shame, arrest, and prison. Subtract the pro-life moral code, the shame, and add gang affiliation and/or long prison experience. Move this sub-population into an urban area and ask yourself the question: Will the prospect of a return to prison deter all these men?

For example, at 113 homicides during 2002, the city of Oakland achieved a homicide rate just under 28 per 100,000, or more than twice the highest homicide rate ever recorded for the state as a whole. Police sources confirm that most of these homicides are being committed by members of a cohort of prison parolees, about 3,000 of whom were recently released from state prison to live in Oakland. The homicide problem can be particularly acute in some urban areas because of concentrations of violence-prone former prison inmates. Most California state prison graduates re-offend after release on parole. Obviously, most of state prison parolees are not adequately deterred by the prospect of further prison. A fortiori, the possibility of mere incarceration even for murder is a very weak deterrent for this sub-population.

A critical moment comes when a prison habituated felon, who is preparing to engage in another crime, chooses to bring along a loaded pistol; a second critical moment comes when he makes the decision to pull the trigger or to refrain from that act. We need to ask: What disincentives will get the attention of this sub group of criminals? In the current punishment scheme, what is there beyond a term for years? There is only life incarceration without parole and, finally, the threat of execution.

Even for those undeterred by the prospect of an additional prison term, some criminals do hesitate when faced with the prospect of a long stay on death row, separated from the general prison population, living with the hovering ghost of the “Green Room.” As more cities like Oakland, California experience the influx of prison habituated released felons in their midst, the need for additional deterrence will grow.

I’m well aware of the psychological and budgetary costs of administering the death penalty. The cases are hard on everyone in the system, especially for those assigned the responsibility of conducting an effective defense. If it were just a question of working conditions in the legal community from which I’ve graduated, I would want to abolish the penalty. But the social costs are too high.

Copyright 2001, 2002, 2003, 2005, 2006, 2008, 2011 by Jay B Gaskill, Attorney at Law, as published on the Policy Think Site ( Contact:

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