This dissertation aims at comparing the efficiency of suggestion pay, performance pay and shares selling, so as to involve employees into suggestions schemes (e.g. quality circles, workshop meetings, suggestion box). In the first chapter, the historical background, the current situation and the state of literature are being investigated. In the following chapter, a simple framework is considered with only one employer and one employee. A formal model of shared ownership that fits with the French scheme of ’capital increase dedicated to the employees’ is sketched. It is shownthat, as long as the employer is not limited in the number of shares he can offer, the scheme performs better than suggestion pay and performance pay. Next chapter builds upon the previous model and extends the results to a broader framework with multiple employees. The fourth chapter presents an empirical study based on the REPONSE survey. The econometric specification and the variables are chosen to fit the theoretical models. The results strongly support the theory.