Richardson, Katarina; den Berg, Gerard J van - C.E.P.R. Discussion Papers - 2006
employment by exploiting variation in the timing of treatment and outcome, dealing with selectivity on unobservables. We … model allowing for duration dependence and unobserved heterogeneity (leading to spurious duration dependence) in the … treatment effect itself, and we prove non-parametric identification. The data cover the population and include multiple …