den Berg, Gerard J. van; Bozio, Antoine; Costa Dias, Monica - Institute for the Study of Labor (IZA) - 2014
Causal effects of a policy change on hazard rates of a duration outcome variable are not identified from a comparison of spells before and after the policy change, if there is unobserved heterogeneity in the effects and no model structure is imposed. We develop a discontinuity approach that...