A new approach to measure tactical voting: evidence from the British elections

Abstract

Although tactical voting attracts a great deal of attention, it is very hard to measure as it requires knowledge of both individuals’ voting choices as well as their unobserved preferences. In this article, we present a simple empirical strategy to nonparametrically identify tactical voting patterns directly from balloting results. This approach allows us to study the magnitude and direction of strategic voting as well as to verify which information voters and parties take into account to determine marginal constituencies. We show that tactical voting played a significant role in the 2010 election, mainly for Liberal–Democratic voters supporting Labour. Moreover, our results suggest that voters seem to form their expectations based on a national swing in vote shares rather than newspaper guides published in the main media outlets or previous election outcomes. We also present some evidence that suggests that campaign spending is not driving tactical voting.

Keywords:

• tactical voting
• British elections
• expectations

JEL Classification:

• H89
• D72
• D84

Acknowledgements

We are particularly indebted to Stéphane Dupraz for his help and assistance. Moreover, we would like to thank Yola Engler and Gabriele Gratton for helpful comments and Justus Inhoffen for research assistance.

Notes

¹ See, for example, Galbraith and Rae (1989), Johnston and Pattie (1991) and Fieldhouse et al. (1996).

² It has become common to refer to this phenomena as ‘tactical voting’ in the context of the British election and as ‘strategic voting’ in the US elections. Here, we do not make this distinction and use the terms interchangeably.

³ The closeness of the election that year was due to the specific national swing observed which in turn was likely driven by short-term changes in the popularity of the different parties.

⁴ In alternative voting systems, or instant run-off voting, instead of voting for a single candidate, voters rank the candidates in order of their preferences. The votes are then counted and candidates ranked as a function of the ‘first preferences’, then the lower ranked candidates are eliminated and the votes in their favour are transferred to the next best preferred candidates of their voters.

⁵ We will discuss later on in more detail how these expectations can be formed.

⁶ But it is certainly not the only system where strategic voting can be expected. For example, Meffert and Gschwend (2010) and McCuen and Morton (2010) find empirical evidence of tactical coalition voting in a proportional representation system, that is voters might try to vote such that they maximize the winning probability of their preferred coalition.

⁷ Cox (1997) provides a comprehensive investigation of this topic.

⁸ See, for example, Niemi et al. (1992), Johnston and Pattie (1991), Lanoue and Bowler (1992), Alvarez and Nagler (2000) and Fisher (2000).

⁹ Blais et al. (2005) provide a comparison of the two main approaches – the direct and the indirect one.

¹⁰ Interestingly, and related to the article at hand, they assume that expectations are formed based on the previous election result. This assumption is strong and is, as we will show later on, empirically most likely not accurate.

¹¹ See also Lanoue and Bowler (1998), Blais and Nadeau (1996), Kim and Fording (2001) and Blais et al. (2001) for studies using the indirect approach of measuring tactical voting.

¹² See also Duch and Palmer (2002), Heath and Evans (1994), Niemi et al. (1992) and Niemi et al. (1993) for studies using the direct approach.

¹³ See also Wright (1990), Wright (1992) and Atkeson (1999) regarding vote misreporting issues and Alvarez and Nagler (2000) who provide a more detailed critique of the empirical tactical voting literature. Blais et al. (2005) discuss advantages and disadvantages of both approaches in more detail.

¹⁴ See, for instance, McCarthy and Ryan (1977) and Upton (1978) for early transition probability estimates (although they do not consider tactical voting in particular).

¹⁵ See also Fieldhouse et al. (1996) and Johnston et al. (1997).

¹⁶ As mentioned before, our approach needs a distinct identification assumption and comes at the cost of not allowing for point estimates. Naturally, all empirical strategies come along with some advantages and some drawbacks.

¹⁷ See Alvarez and Nagler (2000), for example.

¹⁸ Additionally, there is a large literature on strategic abstention in elections when voters do not have perfect information about the state of the world. In that case, some voters are potentially better informed than others. This line of research has produced some interesting theoretical and experimental results and is especially connected with the work by Feddersen and Pesendorfer (1996), who show that less informed voters may strictly prefer to abstain even when voting is costless.

¹⁹ Two swingometers are available at the BBC homepage at <http://news.bbc.co.uk/2/hi/uk_news/politics/election_2010/8609989.stm> and at <http://news.bbc.co.uk/2/hi/uk_news/politics/election_2010/8574653.stm>.

²⁰ Details on the selection of constituencies are provided in the ‘Appendix’.

²¹ We describe in the ‘Appendix’ how these notional results are built.

²² This is in line with the study by Lanoue and Bowler (1992), who found that the media did not seem to have a significant influence on tactical voting in 1983 and 1987.

²³ See Ali (1979), Pope and Peel (1989), Franck et al. (2010), Wolfers and Zitzewitz (2004) and Arrow et al. (2008).

²⁴ According to the 2010 British Gambling prevalence survey which surveyed a representative sample of the British population, 43% of the respondents had gambled the week before participating in the survey (British Prevalence Survey 2010, p. 23). Additional evidence of the importance of gambling activities in Great Britain comes from Rosenbaum (1999), who states that betting at British General Elections is a popular pastime which ‘involves many members of the general public and large sums of money’ (Rosenbaum, 1999, p. 1).

²⁵ Another related but different literature deals with the question how effective campaign spending is and whether there are differences in the effectiveness for incumbents relative to challengers. Among these papers are Levitt (1994), Gerber (1998) and Stratmann (2006).

²⁶ See Galbraith and Rae (1989), Johnston et al. (1997) and Fisher (2001), for example.

²⁷ See Fieldhouse et al. (1996) and Pattie and Johnston (2010).

²⁸ This is in line with recent conjectures that the Conservatives are less effective in campaigning, see Pattie and Johnston (2010), for example.

²⁹ But also some empirical studies, see, for example, Cain (1978).

³⁰ See proposition 6 in Myatt (2007).

³¹ Using a logit model to control for distance from contention of the third party, Fisher (2000) analyses survey data from the British Election study and found some support for Myatt’s prediction for the years 1983 and 1987, but not for 1992 and 1997.

³² Please consult the ‘Appendix’ for more details on the sample selection.

³³ We thank a referee for bringing up this important point.

Additional information

Funding

Muller gratefully acknowledges support from the SFB-884 at the University of Mannheim.