More Guns Less Crime (40 page)

Pooled, cross-sectional, time-series data: Data that allow the researcher not only to compare differences across geographic areas, but also to see how these differences change across geographic areas over time.

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Regression: A statistical technique that essentially lets us fit a line to a data set to determine the relationship between variables.

Statistical significance: A measure used to indicate how certain we can be that the impact of a variable is different from some value (usually whether it is different from zero).

Time-series data: Data that provide information about a particular place over time. For example, time-series data might examine the change in the crime rate for a city over many years.

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Description of the Data

This appendix provides a detailed discussion of the variables used in this study and their sources. The number of arrests and offenses for each crime in every county from 1977 to 1992 were provided by the FBI's Uniform Crime Reports (UCR). The UCR program is a nationwide, cooperative statistical effort by over 16,000 city, county, and state law-enforcement agencies to compile data on crimes that are reported to them. During 1993, law-enforcement agencies active in the UCR program represented over 245 million U.S. inhabitants, or 95 percent of the total population. The coverage amounted to 97 percent of the U.S. population living in Metropolitan Statistical Areas (MSAs) and 86 percent of the population in non-MSA cities and in rural counties. 1 The Supplementary Homicide Reports of the UCR supplied the data on the sex and race of victims and on whatever relationship might have existed between victim and offender. 2

The regressions report results from a subset of the UCR data set, though we also ran the regressions with the entire data set. The main differences were that the effect of concealed-handgun laws on murder was greater than what is reported in this study, and the effects on rape and aggravated assault were smaller. Observations were eliminated because of changes in reporting practices or definitions of crimes; see Crime in the United States for the years 1977 to 1992. For example, from 1985 to 1994, Illinois operated under a unique, "gender-neutral" definition of sex offenses. Another example involves Cook County, Illinois, from 1981 to 1984, which experienced a large jump in reported crime because of a change in the way officers were trained to report crime.

The additional observations that were either never provided or were dropped from the data set include those from Arizona (1980), Florida (1988), Georgia (1980), Kentucky (1988), and Iowa (1991). Data for counties containing the following cities were also eliminated for the crime rates listed: violent crime and aggravated assault for Steubenville, Ohio (1977— 89); violent crime and aggravated assault for Youngstown, Ohio (1977— 87); violent crime, aggravated assault, and burglary for Mobile, Alabama

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(1977-85); violent crime and aggravated assault for Oakland, California (1977-90); violent crime and aggravated assault for Milwaukee, Wisconsin (1977-85); all crime categories for Glendale, Arizona (1977-84); violent crime and aggravated assault for Jackson, Mississippi (1977 and 1982); violent crime and aggravated assault for Aurora, Colorado (1977 and 1982); violent crime and aggravated assault for Beaumont, Texas (1977 and 1982); violent crime and aggravated assault for Corpus Christi, Texas (1977 and 1982); violent crime and rape for Macon, Georgia (1977-81); violent crime, property crime, robbery, and larceny for Cleveland, Ohio (1977—81); violent crime and aggravated assault for Omaha, Nebraska (1977—81); all crime categories for Eau Claire, Wisconsin (1977—78); all crime categories for Green Bay, Wisconsin (1977); and all crime categories for Little Rock, Arkansas (1977-79).

The original Uniform Crime Report data set did not have arrest data for Hawaii in 1982. These missing observations were supplied to us by the Hawaii UCR program. In the original data set several observations included two observations for the same county and year identifiers. The incorrect observations were deleted from the data.

For all of the different crime rates, if the true rate was zero, we added 0.1 before we took the natural log of those values. It is not possible to take the natural log of zero, because any change from zero is an infinite percentage change. For the accident rates and the supplementary homicide data, if the true rate was zero, we added 0.01 before we took the natural logs of those values. 3

The number of police in a state, the number of officers who have the power to make arrests, and police payrolls for each state by type of officer are available for 1982 to 1992 from the U.S. Department of Justice's Expenditure and Employment Data for the Criminal Justice System.

The data on age, sex, and racial distributions estimate the population in each county on July 1 of the respective years. The population is divided into five-year age segments, and race is categorized as white, black, and neither white nor black. The population data, with the exception of 1990 and 1992, were obtained from the U.S. Bureau of the Census. 4 The estimates use modified census data as anchor points and then employ an iterative proportional-fitting technique to estimate intercensal populations. The process ensures that the county-level estimates are consistent with estimates of July 1 national and state populations by age, sex, and race. The age distributions of large military installations, colleges, and institutions were estimated by a separate procedure. The counties for which special adjustments were made are listed in the report. 5 The 1990 and 1992 estimates have not yet been completed by the Bureau of the

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Census and made available for distribution. We estimated the 1990 data by taking an average of the 1989 and 1991 data. We estimated the 1992 data by multiplying the 1991 populations by the 1990—91 growth rate of each county's population.

Data on income, unemployment, income maintenance, and retirement were obtained by the Regional Economic Information System (REIS). Income maintenance includes Supplemental Security Insurance (SSI), Aid to Families with Dependent Children (AFDC), and food stamps. Unemployment benefits include state unemployment insurance compensation, Unemployment for federal employees, unemployment for railroad employees, and unemployment for veterans. Retirement payments include old-age survivor and disability payments, federal civil employee retirement payments, military retirement payments, state and local government employee retirement payments, and workers compensation payments (both federal and state). Nominal values were converted to real values by using the consumer price index. 6 The index uses the average consumer price index for July 1983 as the base period. County codes for twenty-five observations did not match any of the county codes listed in the ICPSR codebook. Those observations were deleted from the sample.

Data concerning the number of concealed-weapons permits for each county were obtained from a variety of sources. Mike Woodward, of the Oregon Law Enforcement and Data System, provided the Oregon data for 1991 and after. The number of permits available for Oregon by county in 1989 was provided by the sheriff's departments of the individual counties. Cari Gerchick, Deputy County Attorney for Maricopa County in Arizona, provided us with the Arizona county-level conviction rates, prison-sentence lengths, and concealed-handgun permits from 1990 to 1995. The Pennsylvania data were obtained from Alan Krug. The National Rifle Association provided data on NRA membership by state from 1977 to 1992. The dates on which states enacted enhanced-sentencing provisions for crimes committed with deadly weapons were obtained from a study by Marvell and Moody. 7 The first year for which the enhanced-sentencing variable equals 1 is weighted by the portion of that first year during which the law was in effect.

For the Arizona regressions, the Brady-law variable is weighted for 1994 by the percentage of the year for which it was in effect (83 percent).

The Bureau of the Census provided data on the area in square miles of each county. Both the total number of unintentional-injury deaths and the number of those involving firearms were obtained from annual issues of Accident Facts and The Vital Statistics of the United States. The classification of types of weapons is from International Statistical Classification of Diseases

and Related Health Problems, vol. 1, 10th ed. The handgun category includes guns for single-hand use, pistols, and revolvers. The total includes all other types of firearms.

The means and standard deviations of the variables are reported in appendix 4.

Appendix Four

National Sample Means and Standard Deviations

Toble A4.1 National Sample Means and Standard Deviations

Variable

Observations Mean

Standard deviation

Gun ownership information:

Nondiscretionary law dummy 50,056 Arrests rates (ratio of arrests to offenses)

0.16

0.368

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Table A4.1 Continued

Variable

Observations Mean

Standard deviation

Rate of accidental deaths from

causes other than guns Rate of total accidental deaths Rate of murders (handguns) Rate of murders (other guns) Income data (all values in real 1983 Real per-capita personal

income Real per-capita unemployment

insurance Real per-capita income

maintenance Real per-capita retirement

(over age 65) Population characteristics County population County population per square

mile State population State NRA membership

(per 100,000 people) Percent voting Republican in

presidential election

'Index crimes represent the total of all violent and property crimes.

Table A4.2 Average percent of the total population in U.S. counties in each age, sex, and race cohort from 1977 to 1992 (50,023 observations)

A ppendix Five

Continuation of the Results from Table 4.2: The Effect of Demographic Characteristics on Crime

Toble A5.1 Continued

Table A5.1 Continued

*The result is statistically significant at the 1 percent level for a two-tailed t-test. **The result is statistically significant at the 5 percent level for a two-tailed t-test. ***The result is statistically significant at the 10 percent level for a two-tailed t-test.

Notes

CHAPTER ONE

1. Gary Kleck, Targeting Guns (Hawthorne, NY: Aldine de Gruyter Publishers, 1997), and David B. Kopel, Guns: Who Should Have Them! 1 (Amherst, NY: Prometheus Books, 1995), pp. 260—61, 300—1. The estimates on the number of guns are very sensitive to the rate at which guns are assumed to wear out. Higher depreciation rates produce a lower estimated current stock. About a third of all guns are handguns.

A recent poll by the Dallas Morning News indicated that "52 percent of the respondents said they or a member of their household own a gun. That response is consistent with Texas Polls dating to 1985 that found more than half of Texans surveyed own guns.

"In the latest poll, of those who said they owned a gun, 43 percent said they had two to five guns; 28 percent said they had one; and 19 percent said they had more than five guns. And of the gun owners polled, 65 percent said they had some type of shooting instruction." See Sylvia Moreno, "Concealed-Gun Law Alters Habits of Some Texans, Poll Finds Supporters, Foes Disagree About What That Means," Dallas Morning News, Nov. 3, 1996, p. 45A. The number of people owning guns is examined in more detail in chapter 3.

2. For example, in Chicago 59 percent of police officers report never having had to fire their guns. See Andrew Martin, "73% of Chicago Cops Have Been Attacked While Doing Their Job," Chicago Tribune, June 17, 1997, p. A3.

3. Dawn Lewis of Texans Against Gun Violence provided a typical reaction from gun-control advocates to the grand jury decision not to charge Gordon Hale. She said, "We are appalled. This law is doing what we expected, causing senseless death." Mark Potok, a Texan, said that the concealed-gun law saved his life. "I did what I thought I had to do," (USA Today, Mar. 22, 1996, p. 3A). For a more recent evaluation of the Texas experience, see "Few Problems Reported After Allowing Concealed Handguns, Officers Say," Fort Worth Star-Telegram, July 16, 1996. By the end of December 1996, more than 120,000 permits had been issued in Texas.

4. Japan Economic Newswire, "US. Jury Clears Man Who Shot Japanese Student," Kyodo News Service, May 24, 1993; and Lori Sham, "Violence Shoots Holes in USA's Tourist Image," USA Today, Sept. 9, 1993, p. 2A.

5. Gary Kleck, Point Blank: Guns and Violence in America (Hawthorne, NY: Aldine de Gruyter Publishers, 1991).

6. John R. Lott, Jr., "Now That the Brady Law Is Law, You Are Not Any Safer Than Before," Philadelphia Inquirer, Feb. 1, 1994, p. A9. For a more detailed breakdown of police shootings in the larger US. cities, see William A. Geller and Michael S. Scott, Deadly Force: What We Know (Washington, DC: Police Executive Research Forum, 1992).

7. "Mexican Woman Who Killed Would-Be Rapist to Turn to Activism," Associated Press Newswire, Feb. 12, 1997, dateline Mexico City.

8. For many examples of how guns have prevented rapes from occurring, see Paxton Quigley, Armed and Female (New York: St. Martin's, 1989).

9. Newspaper stories abound. Examples of pizza deliverymen defending themselves can be found in the Chicago Tribune, May 22, 1997, p. 1; Baltimore Sun, Aug. 9, 1996, p. Bl; Tampa

264/NOTES TO PAGES 3-4

Tribune, Dec. 27, 1996, p. Al; and Los Angeles Times, Jan. 28, 1997, p. Bl. Another recent example involved a pizza deliveryman in New Paltz, NY (Middletown (New York) Times Herald Record, Jan. 25, 1997). Examples of thwarted carjackings (Little Rock Democrat-Gazette, Aug. 3, 1996) and robberies at automatic teller machines (York (Pennsylvania) Daily Record, April 25, 19%) are also common.

For a case in which a gun was merely brandished to stop an armed street robbery, see the Annapolis Capitol, Aug. 7, 1996. Other examples of street robberies that were foiled by law-abiding citizens using concealed handguns include the case of Francisco Castellano, who was shot in the chest during an attempted street robbery by two perpetrators but was able to draw his own handgun and fire back. Castellano's actions caused the robbers to flee the scene (Corey Dada and Ivonne Perez, "Armed Robbery Botched as Restaurateur Shoots Back," Miami Herald, Aug. 3, 1996, p. B6.) The following story gives another example: "Curtis Smalls was standing outside the USF&G building when he was attacked by two thugs. They knocked him down, robbed, and stabbed him. Mr. Smalls pulled a .38-caliber revolver and shot both attackers, who were later charged with this attack and two other robberies and are suspects in at least 15 more robberies." This story was described in "Gun Laws Render Us Self-Defenseless," Baltimore Sun, Sept. 27, 1996. See also Charles Strouse, "Attacker Killed by His Victim," Fort Lauderdale (Florida) Sun-Sentinel, Sept. 16, 1997, p. 4B; Henry Pierson Curtis, "Bicyclist Kills Man Who Tried to Rob Him," Orlando Sentinel, Sept. 19, 1997, p. D3; and Florence (Alabama) Times Daily, Dec. 27, 1996, for other examples. Examples of foiled carjackings can be found in "Guns and Carjacking: This Is My Car," Economist, Sept. 20,1997. Many other types of robberies have been foiled by people carrying concealed handguns. In at least one case, citizens carrying concealed handguns in Jacksonville, Florida may have saved a restaurant waitress from being shot ("Pistol-Packing Seniors in Florida Wound Robber," Reuter Information Service, Sept. 24, 1997, 6:15 p.m. EDT). For another example, see Clea Benson, "Wounded Barmaid Kills Gunman in Holdup," Philadelphia Inquirer, Jan. 23, 1997, p. Rl.