Student employment is usually thought to curb academic achievement. Our research relating to a survey at a French university in 2012 emphasizes the significance of the intensity of student working hours. Allowance for the endogeneity of student employment reinforces the negative effects, particularly for young people working more than 16 hours a week. However, the academic achievement of those working fewer than 8 hours per week seems unaffected. The type of employment also affects the chances of success: students with public sector jobs appear to be less prone to failure, possibly because of more flexible working hours.