Journal article: A growing literature has concluded that terrorism affects the economy, yet less is known about its impact on individual welfare. This article estimates the impact of the 2013 Boston marathon bombing on well-being, exploiting representative daily data from the American Time Use Survey and Well-Being Supplement. Using a combined regression discontinuity and differences-in-differences design, with the 2012 Boston marathon as a counterfactual, we find an immediate reduction in well-being of a third of a standard deviation. In particular, happiness declined sharply and negative emotions rose significantly. While the effects do not persist beyond one week, they may entail adverse health and economic consequences.