Reading between the lines: party cues and SNP support for Scottish independence and Brexit

ABSTRACT

Scotland’s future within the European Union (EU) played a prominent role in the 2014 independence referendum. The story goes that latent supporters of independence voted to stay within the UK to maintain EU access. Defeated, Scottish leaders declared the referendum a once-in-a-life-time event only repeated if conditions substantially changed. With the UK now facing a chaotic exit from the EU, proponents of Scottish independence have suggested that a second referendum may occur after Brexit negotiations are completed. Faced with a consensus among Scottish party leaders in supporting EU membership, those hoping for a second independence referendum, we argue, looked to alternate sources of information that saw Brexit as an opportunity to create the conditions that would spur a second referendum. Using panel data from the British Election Study, we examine whether Scottish voters voted tactically to leave the EU. We argue that Scottish National Party voters were likely to interpret statements on the conditions for a second independence referendum as an implicit signal to vote “Leave.” The results have important implications for the role of referendums in representative democracy, strategic voting, and the importance of intra-party division on individual vote choices.

Acknowledgements

Earlier versions of this paper were presented at the Impact of the 2016 Referendum on UK Membership in the EU Conference at Newcastle University (September 16, 2016) and the 16th Annual Faculty Research Conference “A Diversity of (European) Identities? From the Subnational to the Supranational” at the University of Pittsburgh (March 16-17, 2017). We would like to thank Maarja Lühiste as well as the participants at these events for their comments on earlier drafts of the project.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Zachary Greene is a Chancellor's Fellow and Lecturer at the University of Strathclyde. His recent work on intra-party politics, election behaviour and strategies, and party policy change can be found in journals such as the British Journal of Political Science, the European Journal of Political Research, Party Politics, and the Journal of European Public Policy. For additional information on his research, see http://www.zacgreene.com.

Jae-Jae Spoon is Associate Professor of Political Science at the University of Pittsburgh. Her work focuses on party competition and party strategy in Europe and has been published in the British Journal of Political Science, the European Journal of Political Research, Comparative Political Studies and by the University of Michigan Press.

Christopher J. Williams holds a PhD in Political Science from the University of North Texas. He is currently an Assistant Professor in the School of Public Affairs at the University of Arkansas at Little Rock. His research focuses on democratic representation, public opinion, political behavior, and political parties.

ORCID

Zachary Greene http://orcid.org/0000-0003-1261-749X

Christopher J. Williams http://orcid.org/0000-0002-2002-6326

Notes

1 See Curtice’s (2016) discussion of the strengths and weaknesses of these polls. This discussion implies that the real increase was smaller, but did increase to majority support for Scottish independence.

2 Importantly, Gordon Wilson’s remarks were repudiated by others in the SNP (see Green 2016), adding to the mixed cues sent by prominent party leaders. We thank a reviewer for drawing our attention to these reactions.

3 We use a number of phrases particular to the campaigns. “Remain” and “Leave” refer to the official electoral campaigns in support of remaining within the EU or leaving the EU since these were the slogans and names endorsed by the campaigns. We also use these terms to refer to the vote itself. We refer to the UK leaving the EU as “Brexit” as politicians and the media often refer to the process.

4 For example, the district encompassing Glasgow city centre achieved a voter turnout of approximately 56.3% in the EU referendum in contrast with 73% turnout in the Edinburgh city centre district (The Electoral Commission 2016).

5 Public support for a second independence referendum soared in the weeks following the EU vote (see Curtice 2016). The initial bump was, however, short-lived. An August poll conducted by YouGov found support for a second referendum declined to 46% (https://yougov.co.uk/news/2016/09/01/).

6 Importantly, Quinlan (2012) does not focus on the role of parties. His findings that the campaign matters in determining vote choice in referendums, however, suggest that in those countries in which parties do become involved in the campaign, their messages will matter.

7 This outcome is different than when the party system is highly divided or polarized. Levendusky (2010), for example, has shown that when elites are more polarized, cues from the party can be clearer. Voters are better able to identify the parties’ positions and their policy views are more consistent with their issue preferences.

8 The internet panel was implemented as an online survey by YouGov from February 2014 to December 2016. For additional information about the survey, see Appendix or Fieldhouse et al. (2016).

9 In the BES Scottish sample, 63% supported Remain; whereas, 62% of Scottish voters actually voted to Remain on 23 June 2016 indicating that the Wave 8 data provide a fairly representative measure of Brexit referendum vote choice.

10 We used Wave 3 data as respondents were more likely to remember exactly how they voted in the Scottish independence referendum when asked soon after casting a ballot rather than years later. In the sample, 47% of Scots recalled voting for independence, whereas 45% of Scots voted for independence on 18 September 2014. This suggests that the Wave 3 data provide a fairly representative measure of Scottish independence referendum vote choice.

11 See Appendix for the questions used to measure these variables.

12 Respondents were asked to answer true or false to the following statements, “Each EU Member State elects the same number of representatives to the European Parliament”; “Switzerland is a member of the EU”; “Croatia is a member of the EU”; “The EU spends more on agriculture than any other policy area”; “The European Court of Human Rights only has jurisdiction over EU members”; “The European Union is made up of 15 member states.” If a respondent answered a question correctly s/he was given 1 point for a maximum of 6 possible points.

13 The scale is based on the difference between responses to the two campaign information variables on the question “To what extent do you agree or disagree with the following statements?” “The leave campaign has provided clear information about why we would be better off leaving the European Union.” “The remain campaign has provided clear information about why we would be better off remaining in the European Union.” Respondents choose between a 5-point scale ranging from “Strongly Disagree” to “Strongly Agree.” To estimate the scale we divide each of the campaign items by 5 so that they range from 0 to 1 and then subtract the values. We then calculated the natural log of the items (plus 1).

14 Despite the overlap in the confidence intervals in the predicted likelihoods presented in Figure 1, the effect is statistically different at the 95% level in Model 1.

15 In Tables A2 and A3 in Appendix, we replicate Model 1 by the respondent’s party identification (Table A2) and Model 3 by interacting a respondent’s party identification with voting for Scottish independence. Although the main English parties were divided, our results suggest their Scottish counterparts were not as overtly divided on the question of whether to leave the EU.

16 Given the prominence of the EU in the Scottish independence referendum, those in support of independence easily could have believed that Brexit would bring about these conditions. Sturgeon commented on the need for a “material change” during a debate between Scottish party leaders held on 6 April by STV in the run-up to the 2016 Holyrood elections (BBC, April 8, 2016). This statement clarified the party’s earlier position requiring that polls consistently show over 60% support for independence (The Scotsman, October 18, 2015).

17 A model without the dummy variables for reported vote in the Scottish independence referendum and identifying with the SNP correctly predicts approximately 77.5% of the EU vote intentions, whereas our fully specified model improves the accuracy rate to 79.2%.