The Journal of Politics


Bandwagon, Underdog, or Projection? Opinion Polls and Electoral Choice in Britain, 1979–1987

Ian McAllistera1 and Donley T. Studlara2

a1 University of New South Wales

a2 Oklahoma State University


Since the widespread use of opinion polls in British general elections began in the 1950s, there has been continuing controversy concerning their impact on the vote. The bandwagon effect sees voters favoring a party that is doing well in the polls, while the underdog effect predicts that support will go to a party trailing in the polls. There is also the possibility of a projection effect, with voters' expectations conforming to their partisanship. The results presented here, applying logistic regression to “exit poll” survey data collected during the 1979, 1983, and 1987 British general election campaigns, find some evidence of a bandwagon effect in all three elections, but no evidence of an underdog effect and only minor evidence of a projection effect. However, there is a consistent interaction between poll influence and those who decided which way to vote during the election campaign, suggesting that opinion polls can facilitate tactical voting, especially in three-party competition.

(Accepted August 25 1989)

(Received September 17 1990)

Ian McAllister is a professor of politics, the University of New South Wales, Canberra, ACT, Australia 2600.

Donley T. Studlar is a professor of political science, Oklahoma State University, Stillwater, OK 74078-0608.