Cite Freyaldenhoven, Simon, Christian Hansen, Jorge Pérez Pérez, and Jesse M. Shapiro. 2021. “Visualization, Identification, and Estimation in the Linear Panel Event-Study Design.” Https://www.nber.org › Papershttps://www.nber.org › Papers. Working Paper Series. National Bureau of Economic Research. https://doi.org/10.3386/w29170.