The Contrat d'Engagement Jeune (CEJ) brings important new features in the field of social policies and of youths employment as it provides a universal coverage for youths aged from 16 to 25. CEJ enlarges the population of eligible youths compared to programs which were previously implemented, it also enforces an intensive program from 15 hours to 20 by week and a much stricter control of attendance. The first goal of this project is to measure the impact of CEJ on professional trajectories of recipients. The second part of the project deals with non take-up of CEJ : there is indeed a risk that eligible youths do not ask the public employment service to benefit from the program. The goal is to propose a measure of this rate of non take-up and to measure the impact of « CEJ rupture » programs aiming at enhancing the take-up rate of CEJ in some areas.