Multiple victim Public Shootings primarily on nondiscretionary (or"shall issue")concealed handgun laws although we also look at evidence on the role of waiting periods and additional penalties imposed on individuals who use guns in the commission of a crime We analyze multiple victim public shootings(hereafter, multiple shootings or killings)in the United States in the period 1977 to 1995. 10 The main advantage of restricting our study to U.s. data is hat we can compare states with and without shall issue laws at different points in time(other things constant)and, therefore, can estimate the effects of a change in the law within a state during the sample period. In contrast, time series data for a single country faces the problem that many different events may occur at around the same time which makes it difficult to disentangle the impact of a change in the law from other factors. And an international study across different countries faces problems in finding comparable data on gun laws, crime rates, and gun ownership Our study ends in 1995 because many of the variables we use are not available after than date A few words about why we study multiple shootings. Aside from the public attention these acts receive, multiple shootings allow us to test the applicability of economics to an area believed to be far outside the domain of economics. Perpetrators of these acts are often thought to be psychotic or irrational and hence not responsive to costs and benefits. Thus, legal sanctions or, as in this case, the prospect of encountering an armed individual during a shooting spree would have no deterrent effect on these individuals. Indeed the act itself is cited as powerful evidence of irrational or psychotic behavior since a sane person would never kill helpless victims in a While the recent rash of public school shootings during the 1997-98 school took place after the period of our study, these incidents raise questions about the unintentional consequences of laws. The five public school shootings took place after a 1995 federal law banned guns (including permitted concealed handguns) within a thousand feet of a school. The possibility exists that attempts to outlaw guns from schools, no matter how well meaning, may have produced perverse effects. It is interesting to note that during the 1977 to 1995 period, 15 shootings took place in schools in states without right-to-carry laws and only one took place in a state with this type of law. There were 19 deaths and 97 injuries in states without the law, while there was one death and two njuries in states with the law
5 Multiple Victim Public Shootings primarily on nondiscretionary (or “shall issue”) concealed handgun laws although we also look at evidence on the role of waiting periods and additional penalties imposed on individuals who use guns in the commission of a crime. We analyze multiple victim public shootings (hereafter, multiple shootings or killings) in the United States in the period 1977 to 1995.10 The main advantage of restricting our study to U.S. data is that we can compare states with and without shall issue laws at different points in time (other things constant) and, therefore, can estimate the effects of a change in the law within a state during the sample period. In contrast, time series data for a single country faces the problem that many different events may occur at around the same time which makes it difficult to disentangle the impact of a change in the law from other factors. And an international study across different countries faces problems in finding comparable data on gun laws, crime rates, and gun ownership. Our study ends in 1995 because many of the variables we use are not available after than date. A few words about why we study multiple shootings. Aside from the public attention these acts receive, multiple shootings allow us to test the applicability of economics to an area believed to be far outside the domain of economics. Perpetrators of these acts are often thought to be psychotic or irrational and hence not responsive to costs and benefits. Thus, legal sanctions or, as in this case, the prospect of encountering an armed individual during a shooting spree would have no deterrent effect on these individuals. Indeed, the act itself is cited as powerful evidence of irrational or psychotic behavior since a sane person would never kill helpless victims in a 10 While the recent rash of public school shootings during the 1997-98 school took place after the period of our study, these incidents raise questions about the unintentional consequences of laws. The five public school shootings took place after a 1995 federal law banned guns (including permitted concealed handguns) within a thousand feet of a school. The possibility exists that attempts to outlaw guns from schools, no matter how well meaning, may have produced perverse effects. It is interesting to note that during the 1977 to 1995 period, 15 shootings took place in schools in states without right-to-carry laws and only one took place in a state with this type of law. There were 19 deaths and 97 injuries in states without the law, while there was one death and two injuries in states with the law
Chicago Law and Economics Working Paper 6 ublic place. The claim is then made that a law permitting individuals to carry concealed weapons couldnt possibly deter shooting sprees in public places(though it might reduce the number of people killed or wounded). And since these laws might well increase the availability of guns to potential perpetrators, the combination of criminal irrationality and greater availability of guns might lead to an increase in the number of incidents of multiple shootings In contrast, the economic model of crime predicts that a shall issue law will raise the potential perpetrator's cost of acting (e.g, he might be wounded or killed if he acts)and lower his expected benefit (e.g, he will do less damage if he encounters armed resistance Although not all offenders will alter their behavior in response to a shall issue law. some individuals will be deterred from ng out a shooting spree because the resulting changes in costs and benefits will be sufficiently large to make their net gain from acting negative How large the deterrent effect is depends on how many potential offenders are close enough to the margin so that the passage of a shall issue law changes the net benefit from positive to negative Economics predicts, therefore, that shall issue laws will reduce the number of mass shootings(subject to the "greater availability of guns qualification noted above)though the magnitude of this response is uncertain a study of multiple shootings also allows us to comp whether a shall issue law will produce a bigger deterrent effect on multiple shootings than on ordinary murders and other crimes. This may appear surprising in light of the claimed irrationality of individuals who go on shooting sprees. But another consideration points in the opposite direction. Suppose a shall issue law deters crime primarily by raising the probability that a perpetrator will encounter a potential victim who is armed. In a single victim crime, this probability is likely to be very low. Hence the deterrent effect of the law-though negative--might be relatively small. Now consider a shooting spree in a public place. The likelihood that one or more potential victims or bystanders are armed would be very large even though the probability that any particular individual is armed is very
Chicago Law and Economics Working Paper 6 public place. The claim is then made that a law permitting individuals to carry concealed weapons couldn’t possibly deter shooting sprees in public places (though it might reduce the number of people killed or wounded). And since these laws might well increase the availability of guns to potential perpetrators, the combination of criminal irrationality and greater availability of guns might lead to an increase in the number of incidents of multiple shootings. In contrast, the economic model of crime predicts that a shall issue law will raise the potential perpetrator’s cost of acting (e.g., he might be wounded or killed if he acts) and lower his expected benefit (e.g., he will do less damage if he encounters armed resistance). Although not all offenders will alter their behavior in response to a shall issue law, some individuals will be deterred from carrying out a shooting spree because the resulting changes in costs and benefits will be sufficiently large to make their net gain from acting negative. How large the deterrent effect is depends on how many potential offenders are close enough to the margin so that the passage of a shall issue law changes the net benefit from positive to negative. Economics predicts, therefore, that shall issue laws will reduce the number of mass shootings (subject to the “greater availability of guns” qualification noted above) though the magnitude of this response is uncertain. A study of multiple shootings also allows us to compare whether a shall issue law will produce a bigger deterrent effect on multiple shootings than on ordinary murders and other crimes. This may appear surprising in light of the claimed irrationality of individuals who go on shooting sprees. But another consideration points in the opposite direction. Suppose a shall issue law deters crime primarily by raising the probability that a perpetrator will encounter a potential victim who is armed. In a single victim crime, this probability is likely to be very low. Hence the deterrent effect of the law—though negative—might be relatively small. Now consider a shooting spree in a public place. The likelihood that one or more potential victims or bystanders are armed would be very large even though the probability that any particular individual is armed is very
Multiple victim Public Shootings low. 11 In principle, this suggests a testable hypothesis: a shall issue law will have a bigger deterrent effect on shooting sprees in public places than on more conventional crimes. Finally because the presence of citizens with concealed handguns may be able to stop attacks before the police are able to arrive, our data also allows us to provide the first evidence that we know of concerning whether the severity of those crimes that still take place can be mitigated Il. Multiple Vict im Public Shootings: A First Look We define a multiple shooting as one in which two or more people are killed or wounded in a public place. "Public place"refers to a shooting that occurred in a church, business, bar, street, government building, public transit, place of employment, park, health care facility, mall or restaurant. We collected data on these shootings from articles reporting multiple shootings during the 1977 to 1995 period in the Lexis/Nexis computerized database. Our sample does not include all multiple shootings in the database We exclude the following: those that were the byproduct of another crime e g, a robbery or drug deal); shootings that involved gang activity (e. g, drive by shootings); professional hits or shootings related to organized crime; and serial killings or killings that took place over the span of more than one day. 2 Although there is no right line between different types of multiple shootings, there are several reasons for limiting our sample as we do 1. One of us has already studied the effects of shall issue laws on murder rates in general. Hence by adding shootings from robberies, II To illustrate, let the probability (p) that a single individual is carrying a concealed handgun equal. 10. Assume further that there are 10 individuals in a public place. Then the probability that at least one of them is armed is about. 65 (=1-(.9) 12 In a recent paper(see T. Petee, K. Padgett and T. York, Debunking the Stereotype: An Examination of Mass Murder in Public Places, 1 Homicide Studies 317(1997)the authors find felony related mass murders account for 36 percent and gang motivated 5.8 percent of mass murder incidents over the 1965 to 1995 period. That study defines mass murders as the killing three or more persons(so it has much fewer incidents than our sample)
7 Multiple Victim Public Shootings low.11 In principle, this suggests a testable hypothesis: a shall issue law will have a bigger deterrent effect on shooting sprees in public places than on more conventional crimes. Finally, because the presence of citizens with concealed handguns may be able to stop attacks before the police are able to arrive, our data also allows us to provide the first evidence that we know of concerning whether the severity of those crimes that still take place can be mitigated. II. Multiple Victim Public Shootings: A First Look We define a multiple shooting as one in which two or more people are killed or wounded in a public place. “Public place” refers to a shooting that occurred in a church, business, bar, street, government building, public transit, place of employment, park, health care facility, mall or restaurant. We collected data on these shootings from articles reporting multiple shootings during the 1977 to 1995 period in the Lexis/Nexis computerized database. Our sample does not include all multiple shootings in the database. We exclude the following: those that were the byproduct of another crime (e.g., a robbery or drug deal); shootings that involved gang activity (e.g., drive by shootings); professional hits or shootings related to organized crime; and serial killings or killings that took place over the span of more than one day.12 Although there is no bright line between different types of multiple shootings, there are several reasons for limiting our sample as we do. 1. One of us has already studied the effects of shall issue laws on murder rates in general. Hence by adding shootings from robberies, 11 To illustrate, let the probability (p) that a single individual is carrying a concealed handgun equal .10. Assume further that there are 10 individuals in a public place. Then the probability that at least one of them is armed is about .65 (= 1 – (.9)10). 12 In a recent paper (see T. Petee, K. Padgett and T. York, Debunking the Stereotype: An Examination of Mass Murder in Public Places, 1 Homicide Studies 317 (1997)) the authors find felony related mass murders account for 36 percent and gang motivated 5.8 percent of mass murder incidents over the 1965 to 1995 period. That study defines mass murders as the killing three or more persons (so it has much fewer incidents than our sample)
Chicago law and economics Working paper gang activity and so forth to our sample we risk duplicating earlier work 2. Shall issue laws permit law-abiding citizens to carry guns so these laws should have little impact on killings related to gang activity, drug deals and organized crime. Individuals involved in these activities are already engaged in unlawful activities that often require them to carry guns. In short, these persons carry guns independent of whether the law permits them to do so. Hence a"shall issue should have little effect on their behavior 3. Restricting our study to shootings in public places allows us to concentrate on places where economic theory suggests that shall issue laws will have their greatest effect. 13 We expect this because more citizens will be carrying concealed handguns in public places after a law allowing them to carry a gun has been passed. and a shall issue law should also be a more effective deterrent if the potential perpetrator either knows or is uncertain whether the intended victim is armed. Conversely the law should have no effect if the offender knows in advance that the victim is not armed. But such knowledge is unlikely for public places. So unless there are explicit restrictions on carrying guns in certain places(e. g, near schools), a shall issue law should increase the likelihood that a potential victim or bystander is armed. 14 4. One can also question our definition of multiple shootings as requiring two or more killings or injuries. Later in the paper we look 13 Alschuler(1997, P. 369)claims that concealed handguns should only deter crimes involving strangers. Our response is that concealed handguns can deter crimes involving acquaintances as well as strangers, though deterrence involving acquaintances might be more easily thought of as similar to open carrying of guns. The big effect of concealed handguns is that they may allot people to be able to now defend themselves outside of their home or busines e he passage of the concealed handgun laws may deter crimes against uaintances simply to the extent to which it increases gun ownership. 14 Most states allow private businesses to decide whether permit holders are allowed to carry concealed handguns on their premises. State rules may also ary with regard to other places such as government buildings, churches, and
Chicago Law and Economics Working Paper 8 gang activity and so forth to our sample we risk duplicating earlier work. 2. Shall issue laws permit law-abiding citizens to carry guns so these laws should have little impact on killings related to gang activity, drug deals and organized crime. Individuals involved in these activities are already engaged in unlawful activities that often require them to carry guns. In short, these persons carry guns independent of whether the law permits them to do so. Hence a “shall issue” should have little effect on their behavior. 3. Restricting our study to shootings in public places allows us to concentrate on places where economic theory suggests that shall issue laws will have their greatest effect.13 We expect this because more citizens will be carrying concealed handguns in public places after a law allowing them to carry a gun has been passed. And a shall issue law should also be a more effective deterrent if the potential perpetrator either knows or is uncertain whether the intended victim is armed. Conversely the law should have no effect if the offender knows in advance that the victim is not armed. But such knowledge is unlikely for public places. So unless there are explicit restrictions on carrying guns in certain places (e.g., near schools), a shall issue law should increase the likelihood that a potential victim or bystander is armed.14 4. One can also question our definition of multiple shootings as requiring two or more killings or injuries. Later in the paper we look 13 Alschuler (1997, p. 369) claims that concealed handguns should only deter crimes involving strangers. Our response is that concealed handguns can deter crimes involving acquaintances as well as strangers, though deterrence involving acquaintances might be more easily thought of as similar to open carrying of guns. The big effect of concealed handguns is that they may allow people to be able to now defend themselves outside of their home or business. The passage of the concealed handgun laws may deter crimes against acquaintances simply to the extent to which it increases gun ownership. 14 Most states allow private businesses to decide whether permit holders are allowed to carry concealed handguns on their premises. State rules may also vary with regard to other places such as government buildings, churches, and bars
Multiple victim Public Shootings at alternative definitions requiring greater number of deaths and Tables 1 and 2 present data on multiple shootings for the United states as a whole. and for states with and without shall issue laws We find that states without shall issue laws had more deaths and injuries from multiple shootings per year(both in absolute numbers and on a per capita basis) during the 1977 to 1995 period Note also that the number of states without shall issue laws declined from 43 to 29 and the percentage of the U.S. population in these states fell from 91.5 to 68 percent in this period. Yet states without shall issue laws still account for the overwhelming majority(often over 90 percent) of deaths and injuries. The different rates of shootings, murders, or injuries are very consistent over time and do not arise from a few unusual years Tables 3 and 4 look more closely at the 14 states that adopted shall issue laws between 1977 and 1995.15(No state has ever repealed this law. Table 3 shows a sharp drop in multiple murders and injuries per 100,000 persons after the passage of a shall issue law Murders fell by 89 percent and injuries by 82 percent. Table 4 indicates that this drop occurred largely during the first full yean. the a state enacted its law (year"" in the first column). Overall, the decline is so large that we observe zero multiple killings in three of the eight years after the passage of a law, an event that did not occur 15 The fourteen states that enacted"shall issue"or"right-to-carry"laws in th 1977 to 1995 period (dates in parentheses)are as follows: Alaska (1994 Arizona (1994), Florida(1987), Georgia(1989), Idaho(1990), Maine (1985). Tennessee(1994), Virginia (1988), West Virginia (1989), and Wyoming (1994). The following eight states had"shall issue"laws over the entire period Alabama, Connecticut, Indiana, New Hampshire, North Dakota, South Dakota, Vermont and Washington. Data on states having laws prior to 1993 are from Clayton E. Cramer and David B Kopel, Shall Issue: The New Wave of Concealed Handgun Permit Laws, 62 Tennessee Law Review, 679(1995) We used a Nexis search to determine the state and date for states passing laws between 1993 and 1995. These two sources were also used in Lott and mustard (1997). Because of objections raised to the dates for"shall issue" laws in Maine and Virginia(see the discussion in Lott and Mustard), the regression analysis presented in part III examines the sensitivity of our findings to alternative dates for Maine and Virginia
9 Multiple Victim Public Shootings at alternative definitions requiring greater number of deaths and injuries. Tables 1 and 2 present data on multiple shootings for the United States as a whole, and for states with and without shall issue laws. We find that states without shall issue laws had more deaths and injuries from multiple shootings per year (both in absolute numbers and on a per capita basis) during the 1977 to 1995 period. Note also that the number of states without shall issue laws declined from 43 to 29 and the percentage of the U.S. population in these states fell from 91.5 to 68 percent in this period. Yet states without shall issue laws still account for the overwhelming majority (often over 90 percent) of deaths and injuries. The different rates of shootings, murders, or injuries are very consistent over time and do not arise from a few unusual years. Tables 3 and 4 look more closely at the 14 states that adopted shall issue laws between 1977 and 1995.15 (No state has ever repealed this law.) Table 3 shows a sharp drop in multiple murders and injuries per 100,000 persons after the passage of a shall issue law. Murders fell by 89 percent and injuries by 82 percent. Table 4 indicates that this drop occurred largely during the first full year after a state enacted its law (year “1” in the first column). Overall, the decline is so large that we observe zero multiple killings in three of the eight years after the passage of a law, an event that did not occur 15 The fourteen states that enacted “shall issue” or “right-to-carry” laws in the 1977 to 1995 period (dates in parentheses) are as follows: Alaska (1994), Arizona (1994), Florida (1987), Georgia (1989), Idaho (1990), Maine (1985), Mississippi (1990), Montana (1991), Oregon (1990), Pennsylvania (1989), Tennessee (1994), Virginia (1988), West Virginia (1989), and Wyoming (1994). The following eight states had “shall issue” laws over the entire period: Alabama, Connecticut, Indiana, New Hampshire, North Dakota, South Dakota, Vermont and Washington. Data on states having laws prior to 1993 are from Clayton E. Cramer and David B. Kopel, Shall Issue: The New Wave of Concealed Handgun Permit Laws, 62 Tennessee Law Review, 679 (1995). We used a Nexis search to determine the state and date for states passing laws between 1993 and 1995. These two sources were also used in Lott and Mustard (1997). Because of objections raised to the dates for “shall issue” laws in Maine and Virginia (see the discussion in Lott and Mustard), the regression analysis presented in part III examines the sensitivity of our findings to alternative dates for Maine and Virginia