Under the Umbrella of Moral Hazard: A Field Experiment with Flu Vaccines
(with Roberto Mosquera and Adrian Chadi)
While flu vaccination increases individual immunity by generating antibodies, individual behavior can counter these benefits. Vaccination rates fall short of levels that could prevent costly epidemics, and moral hazard can counter the effectiveness of the vaccine. We study how economic factors affect the decision to vaccinate, and whether changes in behavior affect the effectiveness of the vaccine. We partnered with a bank in Ecuador that allowed us to experimentally modify its annual vaccination program. A rich dataset of administrative records and employee surveys allows us to discuss the mechanisms behind our results on both determinants and effectiveness of flu vaccination. We find that opportunity costs play an important role in vaccine take-up. Take-up doubles by assigning employees to get the flu shot during a workday compared to Saturday. Peers’ take-up also increases individual take-up in a meaningful way. With respect to the effectiveness of the vaccine, while the time-exact data shows there is a negative correlation between getting a flu shot and cases of flu-related illnesses, the effect of exogenous vaccination is a precise zero. We present evidence consistent with a change towards riskier behavior that suggests that vaccinated individuals expose themselves more to the virus, and rule out other potential mechanisms.
A Natural Experiment on Television and Well-Being
(with Adrian Chadi)
Watching television is the most time-consuming human activity besides work. Based on previous research, television consumption is detrimental to individual well-being. Hence, economists view this as an example of irrational behavior. This relies on the popular but false belief that research has provided convincing evidence on the negative well-being effects of watching TV. We therefore question this notion by taking advantage of a natural experiment in which access to television signals was quasi-randomly assigned to West German households. Longitudinal data from the German Socio-Economic Panel allows us to determine how signal reception affects psychological outcomes. Contrary to previous research, we observe significant increases in life satisfaction when people watch more television.