A study of income-motivated behavior among general practitioners in the Norwegian list patient system

In the Norwegian capitation system each general practitioner (GP) has a personal list of patients. The payment system is a mix of a capitation fee and fee-for-service. From a model of a GP’s decisions we derive the optimal practice profile contingent on whether a GP experiences a shortage of patients or not. We also find the conditions for whether a GP, who experiences a shortage of patients, is likely to increase the number of services he provides to his patients. Data give us the opportunity to reveal patient shortage, i.e. a positive difference between a GP’s preferred and actual list size, at the individual practice level. From the analysis of 2587 Norwegian GPs (out of a total 3650) the main result is that patient shortage has a positive effect on a GP’s intensity of service provision and hence, on the income per listed person. We also find that a GP’s income per listed person is influenced by the composition of the list according to indicators of need for services, and of accessibility according to the GP density in the municipality. These results are also valid when possible selection bias is accounted for, although the magnitude of the effects is then smaller.