Research

We study how group size influences free-riding on shared resources. We leverage data from buildings that initially lacked apartment-specific heat meters, such that tenants had to share a common heating bill. We analyze the staggered rollout of a corrective technology, "submetering," across buildings of different sizes. Our estimates suggest that individual billing reduced heating expenses by 17%, on average. Machine learning techniques reveal substantial effect heterogeneity, consistent with coordination failure in larger buildings and strategic exit of free-riders.  While submetering improves welfare for most buildings, tenants in smaller buildings show minimal response, both in terms of consumption and price elasticity. We also show that households who share a common heating bill are surprisingly price elastic, implying that only a minority exploits the free-riding incentive. We argue that our results can be explained by "schmeduling," inattention to the billing regime, and pro-social behavior. 

Evaluations of economic interventions usually focus on one target behavior. This study extends the evaluation scope to multiple untargeted behaviors. We evaluate a hot water saving intervention in a natural field experiment. Despite an exclusive focus on hot water, the intervention changes multiple behaviors. Notably, we find a 5.6 percent reduction in room heating energy consumption that persists one year after the intervention. We show that the room heating spillover has important welfare implications.

Mobile applications hold promise to foster sustainable mobility behavior, but evaluations of their effectiveness are subject to a number of empirical challenges. We conduct a randomized controlled trial with three distinctive features: unobtrusive tracking of the control group, limited sample attrition, and a representative sample. In our study, 410 participants track their mobility behavior over a five week period. After one week, the treatment group engages with the user interface of the "Swiss Climate Challenge App". The user interface combines information on individual CO2 emissions with gamification features. We find a treatment effect that implies a 9.8% reduction in emissions caused by access to the mobile application. While we lack the statistical power to exclude a zero average effect, we find statistically significant emission reductions in the second half of the intervention period, among subjects in medium population density areas, and among men. Our findings suggest that mobile applications could generate considerable net benefits, but larger studies will be needed for validation.

Search frictions impede the labor market. Despite this indisputable fact, it is a priori unclear how job search costs affect search duration and unemployment: lower search costs make it easier to find a job, reducing search duration and unemployment, but may also increase the reservation wage, increasing search duration and unemployment. I collaborate with a recruiting company to directly test the effects of lower search costs in a field experiment among approximately 400 IT professionals in Switzerland. I find that workers are more likely to search for detailed job information, but not to file a job application, when search costs are lower. These findings are consistent with an increase in the reservation wage. Lower search costs might lead to picky workers, but fail to ultimately reduce search duration and unemployment.

Estimates of the effect of fetal health shocks may suffer from survivorship bias. The fetal origins literature seemingly agrees that survivorship bias is innocuous in the sense that it induces a bias toward zero. Arguably, however, selective mortality can imply a bias away from zero. In the case of the 1918 flu pandemic, a suppressed immune system may have been protective against the most severe consequences of infection. We use historical birth records from the maternity hospital of Bern, Switzerland, to evaluate this possibility. Our results suggest that a careful consideration of survivorship bias is imperative for the evaluation of the 1918 flu pandemic and other fetal health shocks.

Despite the growing incidence of cesarean deliveries (CDs), procedure costs and benefits continue to be controversially discussed. In this study, we identify the effects of CDs on subsequent fertility and maternal labor supply by exploiting the fact that obstetricians are less likely to undertake CDs on weekends and public holidays and have a greater incentive to perform them on Fridays and days preceding public holidays. To do so, we adopt high-quality administrative data from Austria. Women giving birth on different days of the week are pre-treatment observationally identical. Our instrumental variable estimates show that a non-planned CD at parity decreases lifecycle fertility by almost 13.6%. This reduction in fertility translates into a temporary increase in maternal employment.