Do Dutch dentists extract monopoly rents?

We exploit lottery-determined admission to dental school to estimate the payoffs to the study of dentistry in the Netherlands. Using data from up to 22 years after the lottery, we find that in most years after graduation dentists earn around 50,000 Euros more than they would earn in their next-best profession. The payoff is larger for men than for women but does not vary with high school GPA. The large payoffs cannot be attributed to longer working hours, larger investments while studying (opportunity costs and direct costs), or unpleasant aspects of working as a dentist. A plausible explanation is that dentists earn a monopoly rent. Results from regressions of dentists' earnings on dentists density are consistent with this, as are the facts that the supply of dentists in the Netherlands is low and that the payoff does not vary with high school GPA.

The effectiveness of medical and vocational interventions for reducing sick leave of self-employed workers.

We investigate whether interventions by (a) medical doctors and (b) occupational specialists are effective in reducing sick leave durations among self-employed workers. Therefore, we exploit unique administrative data comprising all sick leave claims by self-employed workers insured with a major Dutch private insurer between January 2009 and March 2014. We estimate a multivariate duration model dealing with nonrandom selection into the two intervention types by controlling for observable and unobservable claimant characteristics. We find adverse treatment effects for both interventions, irrespective of whether they are started early or (middle) late in the sickness spell.

Assessing the impact of obesity on labor market outcomes.

We study the effect of obesity on employment, using rich data from the British National Child Development Study (NCDS). The results show a significant negative association between obesity and employment even after controlling for a rich set of demographic, socioeconomic, environmental and behavioral variables. In order to account for the endogeneity of obesity, we use and assess instruments introduced by Cawley (2004); the obesity status of biological relatives. Using parental obesity as an instrument, we show that the association between obesity and employment is no longer significant. Similar results are obtained in a model of first differences. We provide a number of different checks on the instruments, by exploiting the richness of the NCDS data. The results show mixed evidence regarding the validity of the instruments.

Parental education and child health: evidence from a schooling reform.

This paper investigates the impact of parental education on child health outcomes. To identify the causal effect we explore exogenous variation in parental education induced by a schooling reform in 1947, which raised the minimum school leaving age in the UK. Findings based on data from the National Child Development Study suggest that increasing the school leaving age by 1 year had little effect on the health of their offspring. Schooling did however improve economic opportunities by reducing financial difficulties among households.