In France, a significant number of General Practitioners (GPs) earn less than 1.5 times the French minimum salary. Using a representative panel of self-employed GPs over the years 1993–2004, this paper tests whether these low-income GPs choose to work less than all other GPs or whether they are constrained to do so. The test is based on measuring reactions to positive and negative demand shocks. As low-income GPs do not increase activity in response to a positive demand shock but decrease activity in response to a negative demand shock, it appears that their low-income status is attributable to a strong preference for leisure