Competition in general practice: Prescriptions to the elderly in a list patient system

▶ The results indicate that the stronger competition a GP faces, the more drugs tend to be prescribed to the elderly patients. ▶ There is evidence that GPs' prescription style may conflict with their role as gatekeepers, and worse, may be hazardous to patients' health. ▶ By exploiting the panel design of the data and suitable econometric methods, we have been able to improve the treatment of an important endogeneity problem in empirical modelling of GP behaviour. ▶ A novelty of the chosen econometric approach is that attention is paid to the fact that patients tend to be attracted to GPs who fit their preferences, by treating GPs' patient composition as endogenous.