Evaluating Methods and Findings from a Study of State Gun Policies

This brief technical report is part of RAND's ongoing Gun Policy in America research initiative. That project's review of the research on firearm policies included an article published in the journal The Lancet titled "Firearm Legislation and Firearm Mortality in the USA: A Cross-Sectional, State-Level Study," which examined the effects of 25 state laws on gun deaths. Given the relevance to RAND's ongoing research, the study team carefully reviewed the article and found several problems in the statistical methods and conclusions. The article's findings appeared likely to support bad gun policies and to hurt future research efforts that could treat them as valid. After reconstructing the data set and reanalyzing the article's models, RAND study team submitted a comment to The Lancet pointing out the significant problems in the article. Because the comment was limited to 250 words, this report provides technical background on the assessment, a detailed account of the errors detected, and statistical support for the RAND study team's conclusions.

Gun Policy in America aims to create a resource for policymakers and the general public to access unbiased information that informs and enables the development of fair and effective firearm policies. The initiative's mixed-methods approach incorporates statistical modeling, expert elicitation, a systematic review and synthesis of the research literature, and other techniques that draw on RAND's expertise in objectively analyzing complex policy challenges.