For almost any social phenomenon there exist a great many different theories seeking to explain the respective social facts. This holds also for the field of political participation which is the subject of this paper. In order to explain why people participate more or less in a conventional or unconventional way, not only hypotheses of sociology and political science might be applied. Economics, too, claims to offer valid explanations. In this situation there arises the problem of which theories are superior. In order to contribute to answering this question, some hypotheses on political participation are stated, based upon utility theory. This ‘economic model’ of (conventional and unconventional) political participation is empirically confronted with two sociological theories of political participation. A theoretical analysis indicates that the economic model implies conditions for the validity of the two sociological theories. Furthermore, a secondary analysis with data from Western Germany showed that the economic model was, in spite of measurement problems, superior to the sociological theories.