The project team developed a new framework for the study of firearm violence within the context of gun culture. The investigators defined gun culture and developed methods by which to measure and analyze its effect on gun violence. The team expanded a multistate-level database on gun ownership, firearm policy, and firearm mortality, and examined the inter-relationship among these factors and gun culture. Results have provided new data to enable public health practitioners to identify strategies for addressing and reducing firearm violence.
- What are the individual and combined impacts of a wide range of state policy approaches to reducing firearm violence?
- What are the specific gun policies that most effectively impact firearm violence?
- Inform policy-makers and others about which firearm policies to support and how to frame them, by identifying individual and combinations of state-level policies that are most effective at reducing firearm violence through the development of a publicly available state firearm laws database.
- Provide an empirical foundation to support novel approaches to reducing firearm violence by influencing the culture of health around guns and gun policy.
Dr. Michael Siegel and his team at the Boston University School of Public Health has launched a comprehensive, publicly available, interactive database of state firearm policies. The database includes data on specific provisions of state-level gun policy over a 26-year period from 1991 to 2016 and is the first step in Dr. Siegel's research project. Future research aims to delve more deeply into the relationship between social gun culture, gun ownership, firearm policy, and firearm violence. This database offers researchers, advocacy groups, and decision-makers data and tools to identify effective strategies for addressing firearm violence. There are several interesting findings that have already resulted from examination of the database.
The Impact of State Firearm Laws on Homicide Rates in Suburban and Rural Areas Compared to Large Cities in the United States, 1991‐2016. Two policies—universal background checks and “may issue” laws that required a heightened showing of suitability for concealed carry—were associated with lower firearm homicide rates in large cities but were not associated with firearm homicide rates in suburban and rural areas. In contrast, laws that prohibited gun possession by people convicted of a violent misdemeanor were associated with lower firearm homicide rates in suburban and rural areas, but were not associated with firearm homicide rates in large cities. Permit requirements were associated with lower firearm homicide rates in both large cities and suburban and rural areas.
Most Effective Policies in Reducing Gun Homicides. Of ten state laws evaluated, three laws are significantly associated with lower homicide rates: 19.3% drop with Violent Misdemeanor laws, 11.1% drop with May issue laws, and a 9.6% drop with Universal background checks. Compared to states without violent misdemeanor, may issue, and universal background check laws in effect, states with just one of these laws experienced 6.2% lower homicide rates, states with two of the laws experienced 13.5% lower homicide rates, and states with all three of the laws in effect experienced 36.1% lower homicide rates. Although laws banning assault weapons or large capacity ammunition magazines may seem like an appropriate response, especially in the context of mass shooting events, there is no significant relationship between these laws and homicide rates. The same is true for stand your ground laws, one gun per month laws, and prohibitions on gun trafficking.
Concealed Firearm Permits and Homicide Rates. "Shall-issue" laws, in which concealed carry permits have to be issued if an individual meets requisite critera, were "significantly associated with 6.5% higher total homicide rates, 8.6% higher firearm homicide rates, and 10.6% higher handgun homicide rates, but were not significantly associated with long-gun or nonfirearm homicide," as compared to "may-issue" laws. "May-issue" laws are laws in which law enforcement has much greater discreation when determining if an individual will be issued a concealed carry permit.
Gun Laws & Intimate Partner Homicide. State laws prohibiting individuals subject to domestic violence-related restraining orders from possessing firearms and requiring them to relinquish firearms already in their possession resulted in lower firearm-related intimate partner homicide rates. Absent the explicit requirement to relinquish firearms, intimate partner homicide rates did not decrease. To be effective in protecting public safety, policy makers should ensure their state laws include enforcement provisions to guarantee that people prohibited from possessing firearms do not have access to weapons.
Firearm Manufacturing Trends. After an overall decrease in domestic firearms production from 1996 through 2004 there was a steady increase from 1.7% in 2005 to 13.8% in 2013, when more than 10 million firearms were produced. This increase in total firearm production was primarily driven by the increased production of pistols and rifles. Similar trends were observed in gun purchases and recovered and traced crime guns. These firearm manufacturing and purchasing trends reveal a shift toward more-lethal weapons, which may reflect a shift in cultural practices and norms related to guns and could inform strategies to reduce firearm violence.
Household Gun Ownership & Youth Suicide Rates. The researchers examined the relationship between levels of household gun ownership in each state in 2004 and the youth suicide rates in those states during the subsequent 10 years (2005-2015), while controlling for the prevalence of youth suicide attempts and other factors that are known to affect suicide risk. The major finding was that for each 10 percentage point increase in household gun ownership, the youth suicide rate in a state increased by 27%. This study demonstrates that the strongest single predictor of a state’s youth suicide rate is the prevalence of household gun ownership in that state. The availability of firearms is contributing to an increase in the number of suicides, not just leading youth to substitute other means of suicide for guns.
Firearm mortality rates including homicide and suicide.
Expansion of the state firearm law database. Comparative analysis of the health impacts of various policies across all 50 states using a linear regression model or a negative binomial model, depending on the distribution of the outcome variable for each research question of interest.
Boston University School of Public Health
Everytown for Gun Safety
Children's Hospital Boston
Duke Sanford School of Public Policy