[From excess to lack of physicians: an attempt to understand...].

Until recently, the fear of a medical plethora was in everybody's mind. Now many stakeholders in public health think that a real shortage in physicians will have to be faced. Demographic data on the flux of physicians from medical school, through postgraduate training, to independent activity, associated to observations of the psycho-social characteristics of the four generations of subjects born during the 20th century, leads to a better understanding of this enigma. Exploring this phenomenon sheds light on migratory movements of physicians, both internal to Europe and worldwide, which can be considered as worrying.