This chapter explores young people’s participation in politics both in terms of electoral behaviour, and with regard to more intense types of involvement in the formal political process. The chapter begins by assessing the relevance of debates over the definition and scope of political participation for the quantitative analysis of young people’s politics. Drawing upon data from the 2001 British Election Study, young people’s participation in the 2001 General Election is explored by developing multivariate models of registration and turnout. Drawing upon data from the 2000/01 General Household Survey, the second part of this chapter investigates the roles of social capital in shaping wider patterns of political participation by young people. Firstly, general issues surrounding the conceptualisation and definition of social capital are reviewed, and their application in relation to the study of young people is introduced. The chapter goes on to outline the operationalisation of social capital adopted here, and to detail the principal results emerging from these analyses. Measuring Political Participation Whilst definitions of participation differ in their scope, citizens’ efforts to influence the policy process are usually central (Finer, 1972; Milbrath and Goel, 1977; Marsh, 1990; Parry et al., 1992). Parry et al. (1992: 16) define political participation as ‘taking part in the processes of formulation, passage and implementation of public policies’. As such, participation is viewed as a form of action rather than simply forms of political behaviour such as discussing politics, media consumption and so on. (These are discussed more fully in Chapter 4.) Ideally, a rigorous conceptualisation of political action would encompass both the diversity of forms of participation, as well as variations in the intensity of involvement. Debates over how participation should be defined partly reflect a tension between these two goals. In some approaches (eg. Milbrath and Goel, 1977), participation is conceived of hierarchically in terms of the intensity of political involvement. Implicit within this view is an understanding of the different forms of participation as essentially additive so that different operational indicators are measuring the same basic phenomenon. In contrast, Parry et al. (1992) view participation as irreducibly multi-dimensional with regard to the skills and knowledge it requires, so that particular forms of participation cannot be arranged on a single hierarchy.