Differential turnout and party advantage in British general elections, 1964-83

Contradictory expectations exist about the effect of differential turnout on party support. This paper estimates the likely changes in party support in Britain under different levels of turnout. By applying multivariate analysis to individual-level data collected in 1964, 1974 and 1983, we argue that there is a consistent Conservative disadvantage in higher turnout, but that the corresponding Labour advantage is either slight or non-existent. The Liberals (and the Alliance in 1983) usually make a modest gain from increased turnout. While the magnitude of these changes in the vote may be small, they have the potential to determine the outcome of closely fought elections.