Article Examines Statistical Models of Measuring Deterrence
In the July 2004 Skeptical Enquirer, Rutgers Sociology professor Ted Goertzel examines the methods - and the variant results that emerge - used in studying the deterrent effect of executions on homicide. Read the article here.

Scientific American Looks at Crime Rates
In his Scientific American magazine article entitled, “The Case of the Unsolved Crime Decline,” criminologist Richard Rosenfeld examines why U.S. crime rates dropped more than 40% in the 1990’s and what lessons current policy-makers can learn from this decline. Rosenfeld provides an overview and evaluation of previous research showing a link in the crime rate decline and factors such as changes in demographics, law-enforcement practices, economic conditions, incarceration rates, domestic violence and firearm policies, and the use of guns by young drug dealers. He concludes that while each of these may have contributed toward the decline in serious violent and property crime rates, some of the policies also produced unintended policy effects that could have been avoided if research-based policy experiments had been conducted. For example, stiffer sentences for adult drug offenders, a policy designed to deter crime, may actually facilitate the criminal careers and shorten the lives of the youthful drug sellers who take their place. Based on his research, Rosenfeld provides three lessons that he believes society can draw that may help anticipate and even head off the next crime rate rise. These lessons include dividing crime trends into their component parts, looking for unintended policy effects and engaging in research-based policy experiments before new programs are implemented. (Scientific American, February 2004)

Study Identifies Flaws in Recent Deterrence Research
A new study conducted by Professor Richard Berk of the UCLA Department of Statistics has identified significant statistical problems with the data analysis used to support recent studies claiming to show that executions deter crime in the United States. In “New Claims about Executions and General Deterrence: Deja Vu All Over Again?,” Professor Berk addresses the problem of “influence,” which occurs when a very small and atypical fraction of the available data dominates the statistical results of a study. He found that this statistical problem is found in a number of recent studies claiming to show that capital punishment deters violent crime. The UCLA study conducted by Berk found that in many instances the number of executions by state and year is the key explanatory variable used by researchers, despite the fact that many states in most years execute no one and few states in particular years execute more than five individuals. These values represent about 1% of the available observations that could have been used by researchers to draw conclusions for earlier studies claiming to find that capital punishment is a deterrent. In Professor Berk’s study, a re-analysis of the existing data shows that claims of deterrence are a statistical artifact of this anomalous 1%.
In the abstract, Berk writes:

“A number of papers have recently appeared claiming to show that in the United States executions deter serious crime. There are many statistical problems with the data analyses reported. This paper addresses the problem of “influence,” which occurs when a very small and atypical fraction of the data dominate the statistical results. The number of executions by state and year is the key explanatory variable, and most states in most years execute no one. A very few states in particular years execute more than 5 individuals. Such values represent about 1% of the available observations. Re-analyses of the existing data are presented showing that claims of deterrence are a statistical artifact of the anomalous 1%.”

(Published on UCLA’s Web site, July 19, 2004).

Gallup Poll Finds Decreased Support for Death Penalty When Compared with Life Sentence
A May 2004 Gallup Poll found that a growing number of Americans support a sentence of life without parole rather than the death penalty for those convicted of murder. Gallup found that 46% of respondents favor life imprisonment over the death penalty, up from 44% in May 2003. During that same time frame, support for capital punishment as an alternative fell from 53% to 50%. The poll also revealed a growing skepticism that the death penalty deters crime, with 62% of those polled saying that it is not a deterrent. These percentages are a dramatic shift from the responses given to this same question in 1991, when 51% of Americans believed the death penalty deterred crime and only 41% believed it did not. Only 55% of those polled responded that they believed the death penalty is implemented fairly, down from 60% in 2003. When not offered an alternative sentence, 71% supported the death penalty and 26% opposed. The overall support is about the same as that reported in 2002, but down from the 80% support in 1994. (Gallup Poll News Service, June 2, 2004) Read the Gallup Press Release.

FBI Report Reveals Murder Rate Rise in the South
According to the FBI’s Preliminary Uniform Crime Report for 2002, the murder rate in the South increased by 2.1% while the murder rate in the Northeast decreased by almost 5%. The South accounts for 82% of all executions since 1976; the Northeast accounts for less than 1%. Read the report. (FBI Preliminary Uniform Crime Report 2002, June 16, 2003).

Capital Punishment and Deterrence: Examining the Effect of Executions on Murder in Texas. Authors John Sorenson, Robert Wrinkle, Victoria Brewer, and James Marquart examined executions in Texas between 1984 and 1997. They speculated that if a deterrent effect were to exist, it would be found in Texas because of the high number of death sentences and executions within the state. Using patterns in executions across the study period and the relatively steady rate of murders in Texas, the authors found no evidence of a deterrent effect. The study concluded that the number of executions was unrelated to murder rates in general, and that the number of executions was unrelated to felony rates. (45 Crime and Delinquency 481-93 (1999)).

Deterrence, Brutalization, and the Death Penalty: Another Examination of Oklahoma’s Return to Capital Punishment. In this study, author William Bailey speculated that if executions had a deterrent effect in Oklahoma, it would be observable by comparing murder rates and rates of sub-types of murder, such as felony-murder, stranger robbery-related killings, stranger non-felony murder, and argument-related killings, before and after the resumption of executions. Bailey examined the period between 1989 and 1991 for total killings and sub-types of killing. After controlling for a number of variables, Bailey found that there was no evidence for a deterrent effect. He did, however, find that there was a significant increase in stranger killings and non-felony stranger killings after Oklahoma resumed executions after a 25-year moratorium. (36 Criminology 711-33 (1998)).

Effects of an Execution on Homicides in California. Author Ernie Thompson examined criminal homicides in Los Angeles before and after California’s execution of Robert Harris in 1992, the state’s first execution after a 25-year moratorium. Thompson found slight increases in homicides during the eight months following the execution. (3 Homicide Studies 129-150 (1999)).

The Geography of Execution: The Capital Punishment Quagmire in America. Keith Harries and Derral Cheatwood studied differences in homicides and violent crime in 293 pairs of counties. Counties were matched in pairs based on geographic location, regional context, historical development, demographic and economic variables. The pairs shared a contiguous border, but differed on use of capital punishment. The authors found no support for a deterrent effect of capital punishment at the county level comparing matched counties inside and outside states with capital punishment, with and without a death row population, and with and without executions. The authors did find higher violent crime rates in death penalty counties. (Rowman and Littlefiled Publishers, Lanham, MD (1997))

Homicide Rates Fall in Canada After Abolition of Death Penalty
The abolition of the death penalty in Canada in 1976 has not led to increased homicide rates. Statistics Canada reports that the number of homicides in Canada in 2001 (554) was 23% lower than the number of homicides in 1975 (721), the year before the death penalty was abolished. In addition, homicide rates in Canada are generally three times lower than homicide rates in the U.S., which uses the death penalty. For example, according to the U.S. Bureau of Justice Statistics, the homicide rate in the U.S. in 1999 was 5.7 per 100,000 population and the rate in Canada was only 1.8. Canada currently sentences those convicted of murder to life sentences with parole eligibility. (Issues, 8/4/02).

Latest Uniform Crime Report Shows Highest Murder Rate Again in the South
The latest FBI Uniform Crime Report shows that in 2000, the national murder rate decreased 3.1% from 1999, with the smallest decline in the South. The South remains the region with the highest murder rate, 6.8 victims per 100,000, compared to 5.1 in the West and Midwest, and 4.0 in the Northeast. (Crime in the U.S. 2000, FBI Uniform Crime Reports, October 2001) Read the report.

Since the death penalty was reinstated, over 80% of all executions have occurred in the South, the region with the highest murder rate. The Northeast, the region with the lowest murder rate, has accounted for less than 1% of the executions.

The FBI report also showed that in 2000, 49% of murder victims were white and 48.5% are black. Although blacks and whites are victims of murder in about equal numbers, over 80% of the victims in death penalty cases resulting in execution since 1976 have been white.

Deterrence: U.S. Murder Rate Greatly Exceeds European Non-Death Penalty Nations
Data released by the British Home Office reveals that the United States, which retains the death penalty, has a murder rate that is more than three times that of many of its European allies that have banned capital punishment. (New York Times, May 11, 2002). The data challenges the argument that the death penalty is a deterrent to murder. There are more than 110 nations around the world that have banned the death penalty in law or practice.

At her weekly Justice Department news briefing, U.S. Attorney General Janet Reno said that she has yet to find any evidence that the death penalty deters crime. “I have inquired for most of my adult life about studies that might show that the death penalty is a deterrent. And I have not seen any research that would substantiate that point,” said Reno. (Reuters, 1/21/00)

The Bureau of Justice Statistics reports that the South repeatedly has the highest murder rate. In 1999, it was the only region with a murder rate above the national rate. The South accounts for 80% of executions. The Northeast, which has less than 1% of all executions in the U.S., has the lowest murder rate.