Selection and Incentive Effects of Gatekeeping on Healthcare Utilisation in Germany - Masterarbeit zur Erlangung des akademischen Grades Master of Science – Volkswirtschaftslehre

The aim of this piece of research was to assess whether or not gatekeeping participation is exogenous with respect to healthcare utilisation. To do so, an endogenous treatment regression model was be employed, which required maximum simulated likelihood estimation. Within this model, a latent factor structure is applied. This procedure allows to separate the effect of selection on unobservables from the causal incentive effect. Results imply that unobservable characteristics are conducive to both healthcare utilisation and gatekeeping participation. Even more so, selection effects outweigh the incentive effects. Overall, gatekeeping participation causally strengthens the role of the general practitioner, decreases emergency admissions, while decreasing both ambulatory and total medical costs. A likelihood-ratio test supports the rejection of exogeneity in three out of four utilisation measures. A literature review to make an informed decision about the required number of simulation draws was conducted. Also, extensive robustness analysis suggests that simulation error did not bias the results.