In this section I discuss my method and case selection for this thesis, and introduce the data used in the analysis of this dissertation.
1.4.1
Method
The primary source of analysis in this thesis is individual-level survey data. This offers a number of benefits when analyzing the behaviour of large populations. First, survey research allows the researcher to identify characteristics and trends within their sample and generalize these onto the real-world population (Johnston,2008). Second, the large-scale adoption of internet-based sur- veys has dramatically reduced the cost of collecting responses, allowing for the collection of larger sample sizes which invariably capture a greater degree of variation within the sample. As many of the most common quantitative analysis techniques such as regression are dependent on variation between observations, this allows for more in-depth analysis of differences between groups in a sam- ple. Third, the anonymity provided by surveys also provides benefits to individual-level research. Research on behaviour is dependent upon subjects providing truthful responses to the best of their ability. When conducted anonymously, respondents face less social pressure to change their answers to be more socially desirable (Tourangeau et al.,2000b).
Finally, as I am interested in the individual motivations and drivers of electoral behaviour in mul- tilevel systems, surveys offer the only feasible way to uncover these individual dynamics among large groups of the population. Aggregate-level data cannot tell us information about individual-level be- haviour or motivation due to the problem of ecological inference (King,2013b). Small-N qualitative research such as focus groups or in-depth interviews also face problems. While they are able to pro- vide much more in-depth insights into the behaviour of certain individuals, we cannot extrapolate
and generalize onto the real population. Survey research offers an ideal middle ground between the two.
1.4.2
Case and Data Selection
Throughout this thesis, I focus on two sub-state areas within the UK: Scotland and Wales. Political decentralization is relatively new to the UK, with devolution only occurring after referendums in 1997. Yet the UK has also been home to long-term territorial heterogeneity when it comes to elec- toral behaviour, particularly in Scotland and Wales (see, for example, Blondel,1963;Hearl et al.,
1996;Mitchell,2009). In this way, the UK offers a unique case where political scientists are able to analyse how voters behave when presented with an entirely new political arena, and a new electoral system to go with it. Yet Scotland and Wales also offer an interesting contrast to one another. Since joining the UK in 1707, Scotland has retained a degree of institutional autonomy, with separate legal and educational systems (Mitchell,2009). In contrast, Wales has been assimilated into the institu- tions of England to a far greater degree (Balsom et al.,1983). Yet it has maintained a distinct culture, with different religious traditions, and a substantial population of first-language Welsh-speakers. These cultural dynamics have often been cited as mechanisms that amplify the influence of sub-state factors in political behaviour (Hough and Jeffery,2003;Jeffery and Hough,2003).
Scotland and Wales also make for useful cases due to the availability of high-quality survey data: dedicated election surveys have been carried out at every devolved election since 1999. These studies provide political scientists with detailed individual-level data on political attitudes and behaviours, with level-specific questions. The devolved election studies are discussed in more detail in Chapter2. Outside of the devolved election studies, the British Election Study also offers a useful source of data for voters in Scotland and Wales. The 2014-2017 British Election Study includes booster samples of respondents in Scotland and Wales providing enough observations to carry out detailed analysis
(Fieldhouse et al.,2018).
The main methodological innovation of this thesis is to combine these data, merging the BES with the devolved election studies. By doing so, I create a new mulitlevel panel that – for the first time in the UK – is able to follow the same voters over time, over multiple election at different lev- els of government. These data also includes questions specific to both levels of government, which means that the data is less vulnerable to vote recall bias. Previously, if scholars were interested in how a respondent voted at a previous election to a different level of government, they were reliant on respondents being able to accurately and honestly volunteer that information. Yet it is well estab- lished in the political science literature that vote recall and vote self-prediction are unreliable (Weir,
1975;Himmelweit et al.,1978;Tourangeau et al.,2000b;Rogers and Aida,2014). This unreliability is heightened by respondents’ current party preferences, at times of party preference volatility, or when asked proximate to a different election (van Elsas et al.,2013). As Chapter5will show, party preferences are not stable between elections to different levels. However, by linking the BES with devolved election studies, previous vote (in addition to numerous other variables of interest) is recorded in the immediate aftermath of the vote, reducing the likelihood of recall bias. It also al- lows for the combination of attitudes from different levels, meaning that the interaction between attitudes and behaviours between levels can be better understood.