A representative sample of more than three thousand members of a German political party were asked in which of eleven party related activities they had been involved. A one-dimensional Guttman scale was found with a maximal e = 17% or 536 violations in a declared zero cell. The construction and evaluation of this scale is described in some detail. We interpret the scale as ordering the activities with respect to the public commitment required on behalf of the party.
A two-dimensional MSA, e < 8%, for the same data found a solution with a fit of f = .979. As always, the first dimension counts the number of items endorsed, interpreted as the amount of involvement for the party. We interpret the poles of the qualitative dimension as 'demonstrating loyalty' versus 'support for the institution . The paths in the Hasse diagram could be given a temporal or biographical meaning (despite the fact that the data are not longitudinal) as different ways or careers from "easy" activities to those showing a very strong identification with this party.
Key words: Guttman scaling, one- and two-dimensional scalogram analysis, participation in political activities, identification with political parties
Introduction to the research problem
Modern representative democracy is unthinkable without political parties. They function as a democratic link between society and government. Rooted in society, political parties articulate the interests of social groups; organized in governmental institutions, they aggregate conflicting interests to political binding decisions. Political parties can fulfill their democratic function only if an active citizenry is willing to engage in them permanently, bringing this democratic link to life. During the last two decades the ability of parties to serve these functions has come under severe stress. The number of citizens interested in joining a political party has steadily declined; and the party members are less inclined to engage in party activities. At the same time, we saw an increase in citizen action committees and social movements, especially in the younger population as the new generation of party members. These diametrically opposed trends have been characterized as de-institutionalization of political participation, indicating a growing tendency of citizens to restrict their participation to a short term engagement and to single issues.
In this problem definition it was the aim of a large-scale party membership study of the Christian Democratic Union of Germany (CDU) to analyse the motivations for intra-party participation and the reasons for their decline (for details see Veen & Neu 1995). In the broader context of this study the specific aim of the following analysis is to elaborate the relationship between various modes of intra-party participation: Do different modes of party activity constitute separate dimensions, or are the "easier" forms connected to the more "difficult"? Could thus the preference for short-term and single-issue participation lead to an engagement on a permanent basis? Could, for example, members attending only party meetings also be expected to stand for elected office in the party organization or in a local or national parliament?
Methodologically this translates to the question whether the various forms of party activity are organized unidimensionally, being structured in a cumulative, hierarchical order (Milbrath 1965, Falke 1981). The alternative hypothesis states that the different modes of participation in the general public (Verba, Nie & Kim 1978; Verba, Schlozman & Brady 1995; Dalton 1996) could be separated empirically for intra-party participation, too.
For the test of these hypotheses, we could draw on the national representative sample of 3411 members of the CDU of Germany. The fieldwork of this standardized face-to-face interview was completed in 1993 in both the Old and New Bundeslander; the sampling institute was BASISRESEARCH. …