Multilevel analysis of the changing relationship between class and party in Britain 1964–1992

Abstract

Previous analyses of the changing relationship between class and vote in Britain have assumed that the British Election Surveys constitute simple random samples. In fact, they are all clustered samples, and the number of sampling points has varied substantially over time. The paper uses the statistical technique of multi-level modelling to investigate the effects of this clustering and compares the results with those obtained with single-level logistic models. In general, the multilevel and single-level models lead to similar conclusions about the changing relation between class and vote; they both show evidence of a change in the class/vote relationship over time. However, the multilevel models also show that, while the clustering does not affect conclusions about the class dealignment debate, there are other important substantive findings which emerge from the multilevel approach. First, there is clear evidence of substantial constituency differences in the intercepts; that is, individuals had very different propensities to vote Conservative in different constituencies. Second, there were also significant constituency differences in class voting, that is, constituencies seemed to vary in their level of class polarization.