We show that the main nonparametric identification finding of Abbring and Van den Berg (2003b, Econometrica) for the effect of a timing-chosen treatment on an event duration of interest does not hold. The main problem is that the identification is based on the competing-risks identification...

This paper discusses the evaluation problem using observational data when the timing of treatment is an outcome of a stochastic process. We show that the duration framework in discrete time provides a fertile ground for effect evaluations. We suggest easy-to-use nonparametric survival function...

We utilize a large-scale randomized social experiment to identify how coworkers affect each other's effort as measured by work absence. The experiment altered the work absence incentives for half of all employees living in Göteborg, Sweden. Using administrative data we are able to recover the...

In this paper we perform inference on the effect of a treatment on survival times in studies where the treatment assignment is not randomized and the assignment time is not known in advance. Two such studies are discussed: a heart transplant program and a study of Swedish unemployed eligible for...

We utilize a large-scale randomized social experiment to identify how coworkers affect each other's effort as measured by work absence. The experiment altered the work absence incentives for half of all employees living in Göteborg, Sweden. Using administrative data we are able to recover the...

Abadie and Imbens (2008, Econometrica) showed that classical bootstrap schemes fail to provide correct inference for K-nearest neighbour (KNN) matching estimators of average causal effects. This is an interesting result showing that bootstrap should not be applied without theoretical...

During the last decade several empirical studies have stressed the importance of norms and social interactions for explaining sickness absence behavior. In this context public discussions about the intentions of the insurance, and of the rights and duties of the receivers, may be important for...

We test if social work norms are important for work absence due to self-perceived sick-ness. To this end, we use a randomized social experiment designed to estimate the effect of monitoring on work absence. The treated were exposed to less monitoring of their eligibility to use sickness...

To study effects of out-of-school learning we use data on boarding home pupils who attended elementary public schools in the 1940's. The out-of-school environment at the boarding homes could be considered being more learner friendly than the home environment on average: the pupils at the...