CONCLUSION

None of the existing data sources, by itself or in combination with

others, provides comprehensive, timely, and accurate data needed to answer

many important questions pertaining to the role of firearms in violent

events. Even some of the most basic descriptive questions cannot be anMEASURING

swered with existing data. For example, the existing data do not reveal

information pertinent to answering the following questions: 12

1. Where do youth who shoot themselves or others obtain their guns?

2. In what proportion of intimate-partner homicides committed with a

gun does the offender also take his or her own life or the lives of the victim’s

children or protectors?

3. Did the number of people shot with assault weapons change after the

passage of the 1994 ban on assault weapons?

4. What are the most common circumstances leading to unintentional

firearm-related deaths? Are particular types or makes and models of firearms

overrepresented in unintentional firearm-related deaths?

5. What proportion of suicide or homicide victims were under the care

of a mental health professional? What proportion were intoxicated with

alcohol or illicit drugs at the time of death? How do these proportions

compare with those for suicides committed by other means?

There are many other such “unanswerable questions” about firearmrelated

violence, and even more that can be answered only with great

ambiguity. Data for estimating firearm-related mortality lack timeliness

and contain only limited information on key circumstantial and weaponrelated

variables. For firearm-related morbidity data, key circumstantial

and weapon-related information is also limited, and no nationally representative

data sources monitor firearm-related hospitalizations and disabilities.

Data on firearm storage practices, weapon carrying, and gun

safety training are not routinely collected. Data for studying noncriminal

violence are lacking.

Significant gaps exist in the nation’s ability to monitor firearm-related

injury and assess firearm-related policies. In the committee’s view, the most

important step to improve understanding of firearms and violence is to

assemble better data. In the absence of improved data, the substantive

questions addressed in this report are not likely to be resolved.

Emerging data have the potential to make important advances in

understanding firearms and violence. In particular, the National Incident-

Based Reporting System and the National Violent Death Reporting System

can provide a wealth of information for characterizing violent events.

Whether these data will also be effective for evaluating the effects of

firearms, injury reduction policies, or other firearm-related policy ques-

12We thank Catherine Barber and David Hemenway of the Harvard School of Public

Health for providing these examples by personal communication.

tions is unknown and will almost certainly depend on the particular application.

No one system will be effective at answering all questions, but it is

important to begin by collecting accurate and reliable data to describe the

basic facts about violent injury and death. Thus, we are encouraged by the

efforts of the Harvard School of Public Health’s Injury Control Research

Center pilot data collection program, as well as the recent seed money

devoted to implement such a system at the CDC. We reiterate recommendations

made by past National Academies committees (e.g., Institute of

Medicine, 1999) and others to support the development and maintenance

of the National Violent Death Reporting System and the National Incident-

Based Reporting System. We also recognize that these types of data

systems have been the subject of great controversy and, in light of wellfounded

concerns, strongly urge that special care be taken to ensure the

credibility of these data.

The design and implementation plans for these and other proposed

data sets need to explicitly consider whether and how some of the more

complex and important policy questions regarding firearms and violence

might be resolved. There are many obstacles for developing better data:

• Methodological issues regarding how different data sets and prior

information might be used to credibly answer the complex causal questions

of interest.

• Survey sampling issues, including how to design surveys to effectively

obtain information on rare outcomes, geographical aggregation,

sample nonrepresentativeness, uncertain accuracy of self- and informant

reports, lack of standardization in data elements, and uncertain reliability

of cause-of-injury and fatality codes.

• Legal and political barriers that may make collecting important

data difficult if not impossible. For example, the 1986 Firearms Owners

Protection Act (the McClure-Volkmer Act) forbids the federal government

from establishing any “system of registration of firearms, firearm owners,

or firearms transactions or distribution.”

All of these issues should be carefully considered before new data collection

efforts are proposed or undertaken. The proliferation of firearm

data sources, without basic efforts to evaluate their validity and reliability,

to determine the possibility for linkages across data sets, and most importantly

to assess exactly which questions can be addressed with a particular

data set, will not lead to better policy research and violence prevention.

Thus, the committee urges that work be started to think carefully about

the prospects for developing data to answer specific policy questions of

interest. The design for collecting data and the analysis of that data should

be selected in light of the particular research question. For example, what

data are needed to support research on a causal model of the relation

between gun ownership or availability and suicide? Building such a model

would presumably involve estimating the probability that an individual

commits suicide conditional on gun ownership (or availability in some

sense). What data are needed to do this? What data are needed to estimate

the effects of policy interventions on the probability of suicide or on the

substitution of other means of suicide for guns? What other prior information

is relevant? What covariates should be included? Are data on them

currently available? Do data on covariates exist in a form that could be

combined with gun ownership or availability data? Is it necessary to construct

a new data set that includes both ownership or availability data and

the covariates?

If one is interested in answering the question of whether adolescents

with a gun in the home are more likely to successfully commit suicide than

adolescents who do not have a gun in their home, then home-level data on

gun possession and adolescent suicide are needed rather than aggregate

data concerning the numbers of guns in circulation. This type of information

could be used to address the basic question of what proportion of the

adolescents with a gun in their home eventually commit suicide with a gun.

Answering causal questions about firearms and suicide may require additional

information.

The same questions can be asked about the probability of committing a

violent crime with a gun conditional on ownership or availability. Similarly,

what data are needed to support improved research on firearms markets

and how criminals or suicide victims obtain firearms? How, if at all,

would improvements in trace data be used in studies of the effects of policy

interventions on firearms markets or any other policy issue? What would

the desired improvements contribute to research on policy interventions for

reducing firearms violence? How can trace data be used, considering the

deficiencies of these data?

Ultimately, linking the research and data questions will help define the

data that are needed. For example, attempting to answer the seemingly

basic research question, “How many times each year do civilians use firearms

defensively?” by using samples of data collected from crimes reported

to the police is a mismatch between the data source and the research question.

These surveys cannot reveal successful forms of resistance that are not

reported to the police.

This effort to think carefully about the data needed to answer some of

the basic research questions should take place in collaboration with survey

statisticians, social scientists, public health researchers, and representatives

from the Bureau of Justice Statistics, the National Institute of Justice, the

Centers for Disease Control and Prevention, the Bureau of Alcohol, Tobacco,

and Firearms, and others. The research program should assess data

limitations of the existing and proposed data sets, regularly report the

results of that research both in the scientific literature and in forums acces52

sible to data users, and propose modifications to the data sources when

needed.

Careful attention should be paid to ownership, and use data. As we

demonstrate repeatedly in this report, the lack of credible data on gun

ownership and limited understanding of the relationship between ownership

and violence are among the most critical data barriers to better understanding

firearm-related violence. Thus, the committee recommends a research

effort to identify ways in which firearms acquisition, ownership, and

use data can be accurately collected with minimal risk to legitimate privacy

concerns.

A starting point is to assess the potential of ongoing surveys. For example,

efforts should be undertaken to assess whether tracing a larger

fraction of guns used in crimes, longitudinal data from the Monitoring The

Future survey, or enhancement of items pertaining to gun ownership in

ongoing national surveys may provide useful research data.

To do this, researchers need access to the data. Thus, the committee

recommends that appropriate access for research purposes be given to the

Monitoring The Future survey, as well as to the data maintained by regulatory

and law enforcement agencies, including the trace data maintained by

BATF, registration data maintained by the FBI and state agencies, and

manufacturing and sales data.13 These data may or may not be useful for

understanding firearms markets and the role of firearms in crime and violence.

However, without access to these systems, researchers are unable to

assess their potential for providing insight into some of the most important

firearms policy and other research questions. We realize that many have

deeply held concerns about expanding the government’s knowledge of who

owns what type of guns and how they are used. We also recognize the

argument that some may refuse to supply such information, especially those

who are most at risk to use guns illegally. More generally, we recognize that

data on firearms ownership and violence have been the subject of great

controversy. Nevertheless, there is a long established tradition of making

sensitive data available to researchers. In light of these well-founded concerns,

the committee strongly recommends that special care be taken to

ensure the integrity of the data collection and dissemination process. Concerns

over security and privacy must be addressed in the granting of greater

access to the existing data and in creating new data on acquisition, ownership,

and use.

13Current law prohibits the FBI from retaining data from background checks. If these data

were retained and provided in an individually identifiable form for research purposes, they

might provide useful information on firearms markets and measures of known gun owners

nationally. To determine the properties of these data, the FBI would need to retain the records

and researchers would need access to test their utility for informing policy.