We use a rigorous three-stage many-analysts design to assess how different researcher decisions-specifically data cleaning, research design, and the interpretation of a policy question-affect the variation in estimated treatment effects. A total of 146 research teams each completed the same...

With only a few exceptions, previous studies on terror attacks and election outcomes have focused on a particular country or attack, limiting their generalizability. Using data on the outcomes of 393 legislative elections held in 39 European countries during the period 1970-2017, we find limited...