Replication Data for: Navigating Potential Pitfalls in Difference-in-Differences Designs: Reconciling Conflicting Findings on Mass Shootings' Effect on Electoral Outcomes

Recent work on the electoral effects of gun violence in the United States relying on the difference-in-differences design has produced conflicting findings that range from null effects to substantively large effects. At the same time, as the difference-in-difference design on which this research has relied has exploded in popularity, scholars have documented several methodological issues this design faces---including potential violations of parallel-trends and unaccounted for treatment effect heterogeneity. Sadly, these pitfalls (and their solutions) have not been fully explored in political science. In this paper, we apply these advancements to the unresolved debate on the effects of gun violence on electoral outcomes in the United States. We show that studies that find a large positive effect of gun violence on Democratic vote share are a product of a failure to properly specify difference-in-differences models when underlying assumptions are unlikely to hold. Once these biases are corrected, shootings show little evidence of sparking large electoral change. Our work clarifies an important unresolved debate and provides a cautionary guide for the many scholars currently employing difference-in-differences designs.