The informal sector is one of the most problematical of the economical information system in general and on the labor market in particular. By its definition and nature, this sector is quantifiable with difficulty ; yet statiscally, some elements of information can be built on the informal...

Social security systems are often treated according to their epistemology. The bismarckian and beverdgian systems could be the origin of all social protection systems. The firs was created by Bismark at 1883 in Germany, it was based on the insurance principal. The beverigian system was...