Lechner, Michael; Rodríguez-Planas, Núria; … - 2015
there is time varying panel non-response. If such non-response does not affect the common-trend assumption, then OLS and FE … are consistent, but OLS is more precise. However, if non-response is affecting the common-trend assumption, then FE … evidence that non‐response is not ignorable for the differences-in-differences estimation. …