Zeoli, A., McCourt, A., Buggs, S., Frattaroli, S., & Webster, D. (2018). Evidence that Gun Laws Can Reduce Intimate Partner Homicides.
In a recent longitudinal analysis (Zeoli et al., 2017), we examined whether state laws are associated with lower rates of IPH. We analyzed the number of IPHs [Intimate Partner Homicides] per year in 45 states over 34 years (1980 to 2013). Five states were not included due to extensive gaps in data on IPH. We also examined specific types of laws for different states, and when each law went into effect, which varied considerably from state to state. For example, enactment dates for laws requiring persons with domestic violence restraining orders (DVROs) to relinquish their guns range from 1993 to 2013 for the states in the study. In addition to the firearm laws under study, our statistical models controlled for the size of the population at risk, national trends in IPH, baseline differences in rates of IPH by state, and state-level factors that have been correlated with IPH, such as police staffing levels, economic indicators, and fluctuations in homicides in general. We included these measures so that variation in IPH rates that was due to these other factors would not be attributed to the firearm laws in our analyses. To test whether each law was correlated with IPH, we analyzed the IPH trend for each state before and after that state enacted the law (for states that have the law). The model assessed the amount of change coincident with the enactment of each law across states to determine average change and whether this change was significant. For something other than the law to produce the correlation observed, it would have to act at the same time each law was enacted in each state, and it would have to produce the effect we hypothesize the law to have. Given that we found significant correlations for multiple firearm laws, this scenario would have to occur for each law, an unlikely scenario.