In their article in this issue of AJPH (p. 1309), Karaye et al. assessed the impact of the New York Secure Ammunition and Firearms Enforcement Act (NY SAFE Act) on firearm-related suicide and homicide rates for the 1999 to 2019 period.1 Introduced in January 2013, the NY SAFE Act contains many provisions going beyond the general federal requirements, such as increased background checks before the purchase of a firearm and ammunition, prohibition of large-capacity magazines and some semiautomatic weapons, a red flag system, and safe storage conditions. The authors’ results indicated that the NY SAFE Act was associated with a significant decrease in firearm-related homicides, whereas firearm-related suicides were not affected. Furthermore, the authors did not observe any substitution effect. Their findings suggest that multicomponent gun control laws can prevent firearm-related homicides.
Their article has two main contributions: (1) the method they used to estimate the impact of the act, which overcame several threats to internal validity usually found in evaluations of gun control laws, and (2) the implications for future studies and public health policy that emerge from their discussion. However, the authors seem to have struggled, for instance, to provide strong hypotheses to explain why the NY SAFE Act was associated with a significant drop in firearms-related homicides but not suicide rates. Here I elaborate on both contributions.
IMPROVING THE INTERNAL VALIDITY OF EVALUATION STUDIES
Laws such as the NY SAFE Act have been introduced not only in the United States but also in Canada, Australia, and New Zealand.1 Several systematic reviews have been conducted to estimate the impact of multicomponent laws.1–4 These reviews reached different conclusions about the potential of multicomponent laws to prevent firearm-related deaths. However, they all concluded that high-quality research was needed. Although some evaluation studies reported that the simultaneous implementation of laws targeting multiple elements of firearm regulations reduced firearm-related deaths in certain countries, Santaella et al. mentioned that “challenges in ecological design and the execution of studies [limit] the confidence in study findings and the conclusions that can be derived from them.”1(p152) Important threats to internal validity have been identified in several evaluations of gun control laws.1,2,4
The evaluation of the NY SAFE Act was based on an innovative quasi-experimental approach to obtaining results with strong internal validity. Karaye et al. were among the first researchers to use the synthetic control method to construct a counterfactual that closely resembles the “treatment” state. The authors used data from a pool of donors—potential control states—and from the pretreatment period to predict what would have happened without the introduction of the NY SAFE Act in 2013. They were able to build a synthetic control region that was similar to the actual state of New York in terms of pretreatment sociodemographic characteristics and mortality rates. Their findings provide strong evidence about the preventive impact of the NY SAFE Act on firearm-related homicides, especially given that no substitution effect was detected. Their study paves the way for future evaluations of gun control laws based on strong quasi-experimental designs.
PREVENTIVE MECHANISMS TRIGGERED BY GUN CONTROL LAWS
Karaye et al.’s discussion shows that additional research needs to be conducted to obtain a comprehensive understanding of the impact of the NY SAFE Act and other similar laws. As suggested by the authors, future studies could evaluate the effect of the act on nonfatal firearm-related injuries and consider individual data. In addition to such suggestions, there is an urgent need for studies that would provide an understanding of the preventive mechanisms that were associated with the decline in firearm-related homicide rates.
There is, at best, scarce knowledge on the cumulative effects of gun control laws, on how provisions are enforced by competent authorities, and on how components of gun control laws interact. To claim that a “treatment” is associated with an outcome, one must not only observe a significant relationship but also be able to provide a credible explanation. This is a basic rule of causal inference. The explanations provided by the authors in interpreting the impact of the NY SAFE Act on suicides and homicides could benefit from new evidence. At least two claims can be challenged on the basis of actual scientific evidence.
First, the authors stressed that the provisions prohibiting some assault weapons and large-capacity magazines could partially explain the observed decrease in firearm-related homicides. These weapons can contribute to mass shootings. The authors’ claims are questionable. On one hand, the effect of the NY SAFE Act on mass shooting incidents or other indicators (e.g., the number of victims per incident) was not assessed. On the other hand, despite some encouraging findings about the preventive effects of banning large-capacity magazines,5 systematic reviews are not in agreement about the impact of gun and ammunition bans. Two systematic reviews were unable to reach conclusions about the impact of such measures because evaluation studies lacked internal validity.1,2 One review indicated that these measures are ineffective6 and another that they are in fact effective.7 Updating these systematic reviews with recent evaluation studies could lead to different conclusions about the impact on gun violence of banning large-capacity ammunition magazines and semiautomatic weapons.
Second, conversely to the homicide rate, suicides did not decline after the introduction of the NY SAFE Act. According to the authors, the effects on suicides could be delayed as suicide prevention efforts involve comprehensive strategies, including improved access to mental health services, community support, and efforts to reduce the stigma associated with mental health issues. This claim is delicate and debatable in it applies to homicide as well. The authors’ message may also be misinterpreted: prevention of homicide goes beyond mere gun control strategies.
Several authors have stressed that prevention of firearm-related homicides needs to be multifaceted and based on a public health approach.8 Accordingly, gun control strategies represent one approach among others. Other prevention measures have proven effective, including law enforcement strategies such as programs based on the focused-deterrence approach,9 prevention projects offered to at-risk youths or youths in high-risk communities,10 education campaigns promoting safe storage conditions,11 and place-based measures such as greening efforts.12 States should consider not only multicomponent laws in their strategy to reduce gun violence but also programs supporting primary, secondary, and tertiary prevention efforts directed at various targets (at-risk youths, blighted vacant lands, potential victims, guns). Considering the polarization of the gun control debate in the United States, researchers and experts need to promote a holistic and intersectoral approach to the prevention of firearm-related violence.8
In conclusion, the Karaye et al. evaluation study provides convincing results regarding the potential of multicomponent gun control laws. Their discussion highlights that there is an urgent need for additional research to build a stronger body of evidence about these laws. More precisely, their discussion shows that additional studies are needed to pinpoint the preventive mechanisms responsible for the decline in firearm-related homicide rates. Similarly, knowledge is scarce about the cumulative effects of gun control laws and other violence reduction measures. Additional knowledge on this latest issue would help further support a multifaceted approach to the prevention of gun violence.
CONFLICTS OF INTEREST
The author declares no conflicts of interest.
See also Karaye et al., p. 1309.
REFERENCES
- 1.Santaella-Tenorio J, Cerdá M, Villaveces A, Galea S. What do we know about the association between firearm legislation and firearm-related injuries? Epidemiol Rev. 2016;38(1):140–157. doi: 10.1093/epirev/mxv012. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Hahn RA, Bilukha O, Crosby A, et al. Firearms laws and the reduction of violence: a systematic review. Am J Prev Med. 2005;28(2):40–71. doi: 10.1016/j.amepre.2004.10.005. [DOI] [PubMed] [Google Scholar]
- 3.McPhedran S.A systematic review of quantitative evidence about the impacts of Australian legislative reform on firearm homicide. 2023. https://www.sciencedirect.com/science/article/abs/pii/S1359178916300258
- 4.Bennett N, Karkada M, Erdogan M, Green RS. The effect of legislation on firearm-related deaths in Canada: a systematic review. CMAJ Open. 2022;10(2):E500–E507. doi: 10.9778/cmajo.20210192. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Siegel M, Goder-Reiser M, Duwe G, Rocque M, Fox JA, Fridel EE. The relation between state gun laws and the incidence and severity of mass public shootings in the United States, 1976–2018. Law Hum Behav. 2020;44(5):347–360. doi: 10.1037/lhb0000378. [DOI] [PubMed] [Google Scholar]
- 6.Lee LK, Fleegler EW, Farrell C, et al. Firearm laws and firearm homicides: a systematic review. JAMA Intern Med. 2017;177(1):106–119. doi: 10.1001/jamainternmed.2016.7051. [DOI] [PubMed] [Google Scholar]
- 7.Makarios MD, Pratt TC. The effectiveness of policies and programs that attempt to reduce firearm violence: a meta-analysis. Crime Delinq. 2012;58(2):222–244. doi: 10.1177/0011128708321321. [DOI] [Google Scholar]
- 8.Cook PJ. Expanding the public health approach to gun violence prevention. Ann Intern Med. 2018;169(10):723–724. doi: 10.7326/M18-2846. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Braga AA, Cook PJ. Policing Gun Violence: Strategic Reforms for Controlling Our Most Pressing Crime Problem. New York, NY: Oxford University Press; 2023. [Google Scholar]
- 10.Petrosino A, Campie P, Pace J, et al. Cross-sector, multi-agency interventions to address urban youth firearms violence: a rapid evidence assessment. Aggress Violent Behav. 2015;22:87–96. doi: 10.1016/j.avb.2015.04.001. [DOI] [Google Scholar]
- 11.Rowhani-Rahbar A, Simonetti JA, Rivara FP. Effectiveness of interventions to promote safe firearm storage. Epidemiol Rev. 2016;38(1):111–124. doi: 10.1093/epirev/mxv006. [DOI] [PubMed] [Google Scholar]
- 12.Moyer R, MacDonald JM, Ridgeway G, Branas CC. Effect of remediating blighted vacant land on shootings: a citywide cluster randomized trial. Am J Public Health. 2019;109(1):140–144. doi: 10.2105/AJPH.2018.304752. [DOI] [PMC free article] [PubMed] [Google Scholar]