Rationality and party activism: Encompassing tests of alternative models of political participation

Abstract. The purpose of this paper is to test a rational actor model of political participation against rival models to see which provides the best theoretical account of participation. This is done using data from the first panel survey of Labour party members in Britain. The tests use encompassing methodology, an approach to model building which arises out of recent developments in applied econometrics. The rational choice model is tested against a social-psychological model, and a ‘general incentives ’ model which has been utilized in earlier research to explain party activism. The results show that while the rational choice model has important explanatory power, it provides an incomplete account of participation. A ‘reduced form ’ model is developed which encompasses the other models, and provides the best explanatory account of party activism