Brexit and the Reshaping of British Electoral Politics

Abstract

The General Elections of 2015 and 2017 marked a historically high level of volatility, both at the aggregate level and at the level of the individual voter. In this chapter we describe how this increased volatility is part of a long-term trend in British politics, but one which accelerated markedly after 2010. At the aggregate level, 2015 and 2017 were the two most volatile elections since 1931. At the individual-level, they were the two most volatile elections we have data to measure. Unlike aggregate volatility, which has changed erratically over time, we show that individual-level volatility has been steadily and significantly increasing since 1964. Moreover, unlike many elections when vote flows favouring one party are compensated by counter-flows favouring another, voters in 2015 and 2017 moved systematically, first away from, and then towards the two major parties.