In this work we tried to model the interaction between workers and firms. The pension system is placed as mediator between interests social in the work market. With the use of both retirement contracts based on the Principal-agent model, we tried to conduct the choice of workers to promote pareto-gains to society trough eficient renewal of labor force. For this purpose, it was necesary to adapt retirement rules to the preferences of worker´s work-leisure choice and to the structure of the market they are inserted in. Contracts defined in a way that disconsider the incentives on the worker have showed the possibility of promoting damage in the form of social costs, competitiveness loss and inificient use of labor.
