Homicide Deaths Among Adult Cohabitants of Handgun Owners in California, 2004 to 2016 : A Cohort Study.

BACKGROUND: Although personal protection is a major motivation for purchasing firearms, existing studies suggest that people living in homes with firearms have higher risks for dying by homicide. Distribution of those risks among household members is poorly understood. OBJECTIVE: To estimate the association between living with a lawful handgun owner and risk for homicide victimization. DESIGN: This retrospective cohort study followed 17.6 million adult residents of California for up to 12 years 2 months (18 October 2004 through 31 December 2016). Cohort members did not own handguns, but some started residing with lawful handgun owners during follow-up. SETTING: California. PARTICIPANTS: 17 569 096 voter registrants aged 21 years or older. MEASUREMENTS: Homicide (overall, by firearm, and by other methods) and homicide occurring in the victim's home. RESULTS: Of 595 448 cohort members who commenced residing with handgun owners, two thirds were women. A total of 737 012 cohort members died; 2293 died by homicide. Overall rates of homicide were more than twice as high among cohabitants of handgun owners than among cohabitants of nonowners (adjusted hazard ratio, 2.33 [95% CI, 1.78 to 3.05]). These elevated rates were driven largely by higher rates of homicide by firearm (adjusted hazard ratio, 2.83 [CI, 2.05 to 3.91]). Among homicides occurring at home, cohabitants of owners had sevenfold higher rates of being fatally shot by a spouse or intimate partner (adjusted hazard ratio, 7.16 [CI, 4.04 to 12.69]); 84% of these victims were female. LIMITATIONS: Some cohort members classified as unexposed may have lived in homes with handguns. Residents of homes with and without handguns may have differed on unobserved traits associated with homicide risk. CONCLUSION: Living with a handgun owner is associated with substantially elevated risk for dying by homicide. Women are disproportionately affected. PRIMARY FUNDING SOURCE: The National Collaborative on Gun Violence Research, the Fund for a Safer Future, the Joyce Foundation, Stanford Law School, and the Stanford University School of Medicine.

Policies to influence perceptions about COVID-19 risk: The case of maps.

Choropleth disease maps are often used to inform the public about the risks posed by coronavirus disease 2019 (COVID-19). In a survey conducted in the U.S. state of Georgia in June 2020, we randomly assigned respondents to view either of two maps. The first map reported county-level COVID case counts; the second displayed case rates per 100,000 people. Respondents who saw case rate maps were less likely to perceive COVID as mostly an urban problem and reported higher levels of concerns about the virus. Case rate maps also increased support for policies aimed at mitigating the spread of the virus, although, for this outcome, the effect was quantitatively small and the maps did not change individuals' self-reported behavior. For several outcomes, the impact of the case rate map was strongest for rural residents and self-identified Republicans, both of whom were less worried about the virus and more skeptical about public health measures to mitigate its spread.

Handgun Ownership and Suicide in California.

BACKGROUND: Research has consistently identified firearm availability as a risk factor for suicide. However, existing studies are relatively small in scale, estimates vary widely, and no study appears to have tracked risks from commencement of firearm ownership. METHODS: We identified handgun acquisitions and deaths in a cohort of 26.3 million male and female residents of California, 21 years old or older, who had not previously acquired handguns. Cohort members were followed for up to 12 years 2 months (from October 18, 2004, to December 31, 2016). We used survival analysis to estimate the relationship between handgun ownership and both all-cause mortality and suicide (by firearm and by other methods) among men and women. The analysis allowed the baseline hazard to vary according to neighborhood and was adjusted for age, race and ethnic group, and ownership of long guns (i.e., rifles or shotguns). RESULTS: A total of 676,425 cohort members acquired one or more handguns, and 1,457,981 died; 17,894 died by suicide, of which 6691 were suicides by firearm. Rates of suicide by any method were higher among handgun owners, with an adjusted hazard ratio of 3.34 for all male owners as compared with male nonowners (95% confidence interval [CI], 3.13 to 3.56) and 7.16 for female owners as compared with female nonowners (95% CI, 6.22 to 8.24). These rates were driven by much higher rates of suicide by firearm among both male and female handgun owners, with a hazard ratio of 7.82 for men (95% CI, 7.26 to 8.43) and 35.15 for women (95% CI, 29.56 to 41.79). Handgun owners did not have higher rates of suicide by other methods or higher all-cause mortality. The risk of suicide by firearm among handgun owners peaked immediately after the first acquisition, but 52% of all suicides by firearm among handgun owners occurred more than 1 year after acquisition. CONCLUSIONS: Handgun ownership is associated with a greatly elevated and enduring risk of suicide by firearm. (Funded by the Fund for a Safer Future and others.).

Assembly of the LongSHOT cohort: public record linkage on a grand scale.

BACKGROUND: Virtually all existing evidence linking access to firearms to elevated risks of mortality and morbidity comes from ecological and case-control studies. To improve understanding of the health risks and benefits of firearm ownership, we launched a cohort study: the Longitudinal Study of Handgun Ownership and Transfer (LongSHOT). METHODS: Using probabilistic matching techniques we linked three sources of individual-level, state-wide data in California: official voter registration records, an archive of lawful handgun transactions and all-cause mortality data. There were nearly 28.8 million unique voter registrants, 5.5 million handgun transfers and 3.1 million deaths during the study period (18 October 2004 to 31 December 2016). The linkage relied on several identifying variables (first, middle and last names; date of birth; sex; residential address) that were available in all three data sets, deploying them in a series of bespoke algorithms. RESULTS: Assembly of the LongSHOT cohort commenced in January 2016 and was completed in March 2019. Approximately three-quarters of matches identified were exact matches on all link variables. The cohort consists of 28.8 million adult residents of California followed for up to 12.2 years. A total of 1.2 million cohort members purchased at least one handgun during the study period, and 1.6 million died. CONCLUSIONS: Three steps taken early may be particularly useful in enhancing the efficiency of large-scale data linkage: thorough data cleaning; assessment of the suitability of off-the-shelf data linkage packages relative to bespoke coding; and careful consideration of the minimum sample size and matching precision needed to support rigorous investigation of the study questions.

Handgun Acquisitions in California After Two Mass Shootings.

BACKGROUND: Mass shootings are common in the United States. They are the most visible form of firearm violence. Their effect on personal decisions to purchase firearms is not well-understood. OBJECTIVE: To determine changes in handgun acquisition patterns after the mass shootings in Newtown, Connecticut, in 2012 and San Bernardino, California, in 2015. DESIGN: Time-series analysis using seasonal autoregressive integrated moving-average (SARIMA) models. SETTING: California. POPULATION: Adults who acquired handguns between 2007 and 2016. MEASUREMENTS: Excess handgun acquisitions (defined as the difference between actual and expected acquisitions) in the 6-week and 12-week periods after each shooting, overall and within subgroups of acquirers. RESULTS: In the 6 weeks after the Newtown and San Bernardino shootings, there were 25 705 (95% prediction interval, 17 411 to 32 788) and 27 413 (prediction interval, 15 188 to 37 734) excess acquisitions, respectively, representing increases of 53% (95% CI, 30% to 80%) and 41% (CI, 19% to 68%) over expected volume. Large increases in acquisitions occurred among white and Hispanic persons, but not among black persons, and among persons with no record of having previously acquired a handgun. After the San Bernardino shootings, acquisition rates increased by 85% among residents of that city and adjacent neighborhoods, compared with 35% elsewhere in California. LIMITATIONS: The data relate to handguns in 1 state. The statistical analysis cannot establish causality. CONCLUSION: Large increases in handgun acquisitions occurred after these 2 mass shootings. The spikes were short-lived and accounted for less than 10% of annual handgun acquisitions statewide. Further research should examine whether repeated shocks of this kind lead to substantial increases in the prevalence of firearm ownership. PRIMARY FUNDING SOURCE: None.

Representation and redistribution in federations.

Many of the world's most populous democracies are political unions composed of states or provinces that are unequally represented in the national legislature. Scattered empirical studies, most of them focusing on the United States, have discovered that overrepresented states appear to receive larger shares of the national budget. Although this relationship is typically attributed to bargaining advantages associated with greater legislative representation, an important threat to empirical identification stems from the fact that the representation scheme was chosen by the provinces. Thus, it is possible that representation and fiscal transfers are both determined by other characteristics of the provinces in a specific country. To obtain an improved estimate of the relationship between representation and redistribution, we collect and analyze provincial-level data from nine federations over several decades, taking advantage of the historical process through which federations formed and expanded. Controlling for a variety of country- and province-level factors and using a variety of estimation techniques, we show that overrepresented provinces in political unions around the world are rather dramatically favored in the distribution of resources.

Política distributiva na Federação: estratégias eleitorais, barganhas legislativas e coalizões de governo / Distributive policy in the Federation: electoral strategies, legislative bargaining and government coalitions

This article discusses and tests different hypotheses about electoral and legislative strategies in Brazil, which is a federation with a strong president, over-representation in both chambers, and members of the legislative branch who are encouraged to seek funds for their constituencies. It examines the geographical distribution of budget and extra-budgetary funds during the period from 1990-2000 and measures the relative importance of captive and undecided districts, over-represented states, state governments, congressional party coalitions and indicators of poverty. It concludes that Brazilian presidents have considerable power over the transfer of resources and use it to preserve their political base in congress. They channel the resources available to them to the states with the largest number of legislators in the governing coalition.