During the past fifty years has published a large amount of work associated with the phenomenon of participation. Also, a good number of companies have chosen to implement procedures that facilitate the participation of operators. We devoted the first part of our job to present the terminology we use in this thesis and identify the most common procedures in firms. Starting with those that allow operators to influence decisions in this group are programs related to both participatory management and industrial democracy or cooperatives. Subsequently, we present the alternatives to carry out economic participation, distinguishing between those which are related to capital and those that are associated with added value. We also estimate the degree of use of these procedures. In the chapter with which we close our review of theoretical work, we worked to identify what outcomes can be achieved with the involvement of workers in decision making. 
In the part devoted to the analysis of data from our fieldwork, we begin by describing the participation programs that use the Spanish companies. Then, we present the results obtained to put in place. For this, we used subjective measures and objective measures. In the next section, we summarize data on the trend that shows the involvement of the future and the kind of internal changes that take place when used. After completing the above, we take care to verify the relationship between program participation and certain characteristics of the company, with the aim of identifying situations where firms are more likely to find participation. Finally, comparing the situation with the Spanish of large U.S. companies.