This paper formulates an econometric framework for studying the impact of interventions on discrete outcomes when responses to treatment vary among observationally identical persons. Using a latent variable model that can be linked to well-posed economic models, we show how to define and...

This paper uses register based data covering the entire population of Danish children enrolled in preschool in 2006-2007 to investigate whether the gender composition of preschool staff members affects the timing of school start and subsequent academic performance. To estimate effects of the...

This paper uses Danish register-based data for the population of children born in 1990-1997 to investigate the effects on parents of having a child with attention-deficit/hyperactivity-disorder (ADHD). Ten years after birth, parents of children diagnosed with ADHD have a 75% higher probability...

We shed new light on the effects of having children on hourly wages by exploiting access to data on the entire population of employed same-sex twins in Denmark. Our second contribution is the use of administrative data on absenteeism; the amount of hours off due to holidays and sickness. Our...