A new paradigm in demographyThe event history approach leads to a new paradigm that may specify the conditions of use of these methods, give its limits and opens to a more synthetic demographic view. Contrary to the paradigm of classical demography, which stated that only one demographic process can be studied at a time and that the process develops in a homogeneous population, it permits to study a complex life course, which depends on the past history and on the information acquired previously. It solves many problems raised by the previous paradigm and opens a very rich way of analysing human behaviour.There is however a risk of committing the atomistic fallacy, since no attention is paid to the context in which human behaviour actually occurs. It seems in this case fallacious to consider individuals in isolation from the constraints imposed by the society and milieu in which they live. Conversely, when using aggregate data, there is a risk of committing the ecological fallacy if you try to detect individual behaviour from aggregate measurements.