A valence model of political competition in Britain: 1992-1997

This paper presents an electoral theorem for the stochastic vote model with multivariate normal disturbances, which gives necessary and sufficient conditions for the validity of the mean voter theorem. The coefficients of a multinomial conditional probit model of the 1979 election in Britain are then examined. On the basis of the estimation, the model involving socio-demographic variables and “valence”, it is concluded that vote maximizing parties would converge to the electoral origin. Since this was not observed, the formal model is extended to include the influence of activists on voter response. A survey of British MPs preferred policy positions in 1997 is used to estimate the positions of party principals, and these are compared with voter estimations of party positions. A second electoral theorem is presented which determines the optimal party location involving a trade-off between principals' preferences and electoral response.