‘A House of One’s Own’: The Effect of Partisanship and Incumbency on Political Trust in Multilevel Systems. The Case of Scotland.

Daniel Devine1

(D.J.Devine@Soton.ac.uk)University of Southampton

ESRC South Coast Doctoral Training Partnership

Paper presented at the Centre for Political Research, KU Leuven

Abstract

How is political trust constructed in multilevel systems? Despite the prevalence of this political arrangement and the importance of political trust, this remains under-theorised with little empirical evidence brought to the question. In this paper, I develop an argument that partisanship matters for political trust in multilevel systems, using the case of Scotland and the UK and a focus on the Scottish National Party. I argue that parties can shape political trust, either positively or negatively, and that this is partly dependent on the incumbent party. The results support this, showing that partisanship matters for political trust, with SNP identifiers more likely to trust the Scottish level and less likely to trust the UK level. However, at the Scottish level, this is dependent on both the Scottish and UK incumbents: when the SNP are in power, SNP identifiers are even more likely to trust the Scottish level. The multilevel nature of the political system also comes in to play, with SNP partisans more likely to trust the Scottish level when the Conservatives are the incumbents in Westminster. The results show the importance of factoring in the multilevel nature of political life and that political parties play a role in this linkage. Partisanship, in the full model, is one of the strongest predictors of trust at the Scottish level.

Introduction1 This paper was presented as part of a research stay at the Centre for Political Research, KU Leuven. I would like to thank the ESRC South Coast DTP for generously funding the stay and Professor Marc Hooghe for hosting me.

Political trust is a fundamental attribute of a democratic society. It is predictive of, amongst other things, unlawful behaviour (Marien and Hooghe, 2011), support for climate change policies (Fairbrother, 2017), and the rise of extreme-right parties (Arzheimer, 2009; Hooghe and Dassonneville, 2016). More normatively, it is seen as an expression of legitimacy in a political system, which is what lay under the motivations of the seminal studies of political support (Crozier et al, 1975; Dalton, 2004). However, how it is constructed in a multilevel system is almost entirely unstudied. This is important because multilevel governance, at least at a local and national level, is a reality for citizens in all countries (Hooghe and Marks, 2001; Hooghe and Marks, 2003); for many, contact with their local or regional level is more substantively important for their daily lives (Kumlin, 2011) and many will conduct democratic life within a regional party system. Given the importance of political trust and the prevalence of multilevel systems, omitting the reality of how politics is conducted is a significant gap in our understanding of political trust.

This paper studies the dynamics of political trust and multilevel politics in the context of Scotland and the UK. The UK provides an appealing setting. Since the 1997 devolution referendum, Scotland has acquired considerable autonomy relating to salient public services like education and health. Alongside this has grown a party system in which a Scottish National Party competes at both Holyrood (the Scottish Parliament) and Westminster elections and where national parties have a separate ‘Scottish’ branding and leadership team. Unsurprisingly given this history, there is also a palpable regional identity. More practically, there is also relatively consistent data on Scottish attitudes since the inception of the Scottish Parliament in the form of the Scottish Social Attitudes (SSA) survey.

This contribution provides one of the first case-specific studies of how political trust is constructed in a multilevel system. It develops an argument, drawing on previous research, that partisanship, conditioned by incumbency at both levels, plays a fundamental role in determining the dynamics of political trust between the Scottish and UK levels. We draw on previous evidence that shows parties can generate both trust and distrust, cohesion or disorder, by the cues they provide to their partisans. With a focus on partisans of the Scottish National Party, the results show that partisanship generates both trust and distrust, but at different levels: we show that partisans of the SNP have considerably more trust in the Scottish Parliament and lower trust in the Westminster Parliament; and for trust in the Scottish Parliament, this is conditioned by which party is the incumbent in both Holyrood and Westminster. In other words, whilst being a partisan of the SNP is related to higher trust in the Scottish Parliament, this is even more true if the SNP are the incumbent at the Scottish level or the Conservatives are the incumbent in the UK. However, SNP partisans are less likely to trust the UK Parliament independent of who is in power. Whilst we do not interact other partisanships with incumbency2, we show that partisans of Labour and the Liberal Democrats are more trusting at both levels whilst Conservative identifiers are more likely to trust the UK Parliament, but less likely to trust the Scottish Parliament. In other words, across all major UK parties, partisanship matters for determining the dynamics of trust in a multilevel political system.

2 Results for these are presented in the Appendix.

We also uncover other interesting dynamics. Having a Scottish identity reduces the probability of trusting the UK Parliament, but has only a slight substantive positive impact on trust at the Scottish level; in other words, it drives distrust, but not trust. This supports a main claim in the literature – that identity has little positive impact on trust – but extends it to claiming it can also generate distrust. The same dynamic is observed for views on Scottish independence. The results also show that trusting one level is nonetheless highly predictive of trust in the other, providing more empirical support for the argument that political trust in multilevel systems is largely congruent between levels.

The following section discusses the extant literature on political trust in multilevel systems and the current explanations of their dynamics. The following section develops the argument regarding partisanship and incumbency and why it might affect political trust. The two sections after present data, method and the results. The paper concludes with a discussion of the results and its contribution to the political trust literature.

Political Trust and Multilevel Systems

The literature on political trust lacks any direct consideration of the dynamics of trust in a multilevel system. Most work, indeed, entirely ignores the multilevel structure of political organisation. This is understandable given the history of the national level being ‘first-order’ and all other levels ‘second-order’ (Reif and Schmitt, 1980). In the political trust literature, much like that of voting behaviour (see e.g Rossteutscher et al, 2015), this perspective has subordinated the role of non-national political arenas to the extent that it is either argued that trust in other arenas is dependent on trust in the national level (i.e, a spill-over effect), or the same theoretical and empirical models for trust in the national level are applied to other arenas (Muñoz, 2017). The result is little theorising about the dynamics of trust in a multilevel system.

There has, of course, been some. Muñoz (2017) shows how that, in almost every country around the world, the ‘closer’ level, be it regional, local, or municipal, is more trusted than the national level. However, this does not, as he says, answer the more fundamental question about how political trust is constructed in multilevel system. It is nonetheless possible to identify three perspectives that do address this question: identity, rationality and congruence. The first two present an argument that the two (or more) levels are judged differently, whilst congruence argue that they are dependent on each other (Muñoz, 2017).

The identity approach takes as its starting point that people that have some identification with a respective level of government will generally have more trust in it. Identity is an expression of community and, as Hooghe and Marks (2009, 2) write, ‘citizens care – passionately – about who exercises authority’. In a multilevel system, it may be that citizens identify more with a region than the national level and this matters because they want to be governed by ‘their own’ (Harteveld et al, 2013). For instance, quite related to the case under study, Liñeira (2016) finds that voter decisions in regional elections are more autonomous from the national level when the voter has a stronger regional identity. Nevertheless, with regard to trust, there is limited evidence that identity matters (Muñoz, 2017; Harteveld et al, 2013).

The rational approach is the most demanding on citizens. This argues that individuals impart trust to each different level of the multilevel system depending on its outcomes (such as policy output) and processes (such as perceived accountability) (Muñoz, 2017; Van der Meer, 2010). This has at least one large assumption. The first is that citizens are able to perceive what objectively good performance is, although previous research has found objective economic performance unrelated to trust (Van der Meer, 2010). The second is that they can attribute responsibility for that performance, good or bad, to different levels, which is problematic in a multilevel system where responsibility is dispersed and often very unclear. Previous research has shown that responsibility attributions are at least in part dependent on in-group biases, where ‘good times’ are attributed to the preferred level (Hobolt and Tilley, 2014) or along with identity (León, 2012). This makes the rationality argument quite demanding on citizens.3

At the other end of the ‘demanding’ continuum is the congruence argument. This posits that trust between levels is more or less the same, and this has two explanations which lead to the same conclusion.4 The first is that citizens cannot really differentiate between levels in a system, and so generalise (usually from the first-order national level) to the rest of the political system (Muñoz, 2017). In other words, there is a general political trust which is then extrapolated to the whole system. This is so partly because citizens have limited political information with which to form opinions; it is the primary arena that matters. The second mechanism is related, but argues that people have a ‘trust syndrome’ (Harteveld et al, 2013). In this model, the reason levels are congruent is because some people are just more trusting and this is largely independent of the political world. When applied to the case of Scotland in the UK, lack of information is unlikely to be a reason for congruence: the Scottish level is highly salient, has its own media market, and a nationalist party that competes successfully at both Westminister and Holyrood elections. If congruence is observed, it is likely to be the latter explanation.

Political Trust, Partisanship and Incumbency

Political parties offer fundamental mediation between citizens and the political system. They offer cues, heuristics and policy packages that individuals use to orientate themselves. This may have ramifications for trust in a multilevel system. This argument is developed here.

Party identity has been seen as a fundamental way through which citizens develop their political preferences (Campbell et al, 1960). In this early conceptualisation, partisanship can be viewed as a ‘perceptual screen’ through which citizens evaluate the political system and orientate themselves towards it. This was seen as a positive: as a

3 The rationality argument is not tested in the models due to missing data; however, it is tested in robustness tests. It finds that perceptions of who benefits from the economy (England or Scotland) matter, as does perceptions of how the economy has performed. However, it does not alter the coefficients nor significance of the main findings. It is not possible with the present data set to test who is responsible for economic performance. 4 An approach in the literature on trust in the EU also argues for a ‘compensation’ argument: that one level is the benchmark for another. In this model, trust at one level is negatively associated with the other. This is not tested here since, in the context of the UK and Scotland, this seems implausible.

consequence of this partisan attachment, partisans should identify more with the political system and act as stakeholders in that same system (Campbell et al, 1960; Hooghe and Oser, 2017). The assumption in this literature is that partisans develop a more positive outlook on the political system as they have a way to express their political preferences (Hooghe and Oser, 2017). In other words, since partisans have a stake in the system and a way to voice their preferences within it, the overall effect on political trust – as an expression of legitimacy of the system - should be positive.

However, more recent developments have argued the contrary. Whilst it may be a form of linkage to the political system, this exact same function may be a problem for wider social cohesion, as it drives group rivalry and social polarisation (Iyengar, 2012; Iyengar and Westwood, 2015; Iyengar, 2016; Mason, 2015). As Hooghe and Olsen (2017, 133) derive from this strand of the literature, this means that ‘partisans will develop an increasingly hostile outlook toward (a substantial part of) society’. These are two competing theories for the effects of partisanship.

Why might this variation in effects exist? The extent to which partisanship leads to more positive or negative perceptions of the political system may depend on the nature of the party and its cues. Specifically, Anderson and Just (2013) show how partisans of parties that have positive positions towards the system have higher levels of support than partisans of parties that have negative positions towards the system. In this reading, partisanship not only channels political support but also shapes it, both positively and negatively. Relatedly, Hooghe and Dassonneville (2016) show how voting for a protest party decreases political trust subsequently. A combined reading of these two literatures leads to an argument that partisanship can be a double-edged sword: it can both generate and deteriorate support for a political system depending on the messages of the party.

It is argued here, then, that partisanship matters: it can generate trust or distrust for the political system, and this can depend on the messages that the party wishes to communicate. However, the context of a multilevel system complicates this relationship. There are multiple levels at which political support can exist, and parties may send messages about multiple levels. Applied to Scotland and the UK specifically, we may expect that the Scottish National Party – given that it is one of independence – aims to generate trust for the Scottish level but distrust for the UK level.

Based on this discussion, we test the following hypotheses regarding the effect of partisanship for the Scottish National Party.

H1a: SNP Partisanship will be associated with higher trust in the Scottish parliament

H1b: SNP partisanship will be associated with lower trust in the UK parliament This could partly depend on which party is in power. It is well established that voters are more likely to trust government (Anderson et al, 2005) and have higher satisfaction with democracy (Singh et al, 2012) if their favoured party has the incumbency, and that incumbency also affects voting behaviour (e.g Weisberg, 2002). Once again, however, this is complicated in a multilevel system where there may be different incumbents at different levels. Previous research has shown this to be the case. Anderson and

LoTempio (2002) find that in the US, results at the Presidential level matter for political support whilst results at the Congressional level do not; Blais and Gélineau (2007) find that outcomes at both constituency and national level increase political support; and Singh et al (2012), who show how winning at a regional level increases political support which is extended to the rest of the political system. To the extent this literature on the winner-loser divide in elections can be applied to incumbency more generally, it provides strong support for varying effects on political support in a political system.

To disentangle the expected effects of incumbency in this context, we refer back to the previous discussion. At the level of the Scottish parliament, the effect following this logic is rather clear: SNP partisans will be more likely to trust the Scottish parliament if the SNP are in power, given what we know about the incumbency effect. However, at the UK level, it is not so easy. On the one hand, it may be that there is no incumbency effect, since the SNP are never in competition for the incumbency, and therefore whoever is in power is no better or worse. On the other, it may be that SNP partisans are more likely to trust the UK parliament if Labour are the incumbent given the more similar policy positions (e.g Wheatley et al, 2012), that a Labour government began the devolution process, and that Labour, until recently, performed well electorally in Scotland. Given this, we test the following hypotheses.

H2a: SNP partisans will have higher trust in the Scottish level when the SNP is the incumbent

H2b: SNP partisans will be unaffected by incumbency in the UK

H2c: SNP partisans will have lower trust in the UK parliament when the Conservatives are the incumbent

Data and Methodology

The data used to test the hypotheses discussed in the previous section comes from the Scottish Social Attitudes survey. The data is available from 1999 to 2015, however, some years are lost due to missing variables.5 There are two full models run and presented below: one for trust in the Scottish Parliament, one for trust in the UK Parliament. Stepwise models are in the appendix.

Accordingly, there are two dependent variables: one for measuring trust in the UK Parliament, the other for trust in the Scottish parliament. In the original survey these are on a four-point scale (almost never, only some of the time, most of the time, just about always), but for the purposes of this analysis it is collapsed into a binary variable. Since the dependent variable is binary, the models are binary logistic regressions.

There are two key independent variables. The first is party identification which is recoded to include just Labour, Conservatives, Scottish National Party (SNP), Liberal Democrat and None/Others. These are included in the model as dummy variables to aid interpretation and includes only partisans of the primary parties (i.e, not those without a party ID). The second is incumbency, which includes a variable for each incumbency at

5 The left-right measure excludes a number of years. The results stay the same excluding it, so for a more complete model I include it.

the UK and Scottish level. These are dummy variables, where, at the Scottish level, 1 = the SNP and 0 = Labour; and at the UK level, 1 = Conservative and 0 = Labour.

Since this is a complicated picture, the figure below graphs the timeline of incumbencies at both levels. At the Scottish level, the SNP are in power from 2007; at the UK level, the Conservatives are in power from 2010. The dashed vertical lines indicate elections. Whilst 2007-2010 (Scotland) and 2010-2015 (UK) are coalitions, these are coded as SNP and Scottish incumbencies respectively, since these parties held the First Minister/Prime Minister post. An additional analysis did account for the coalition/majority division, coding incumbency as 0-2, and this made little difference. There was a slight change for the SNP majority, but none at the UK level.

Figure 1 - Incumbencies in Westminster and Holyrood

The somewhat patchy nature of the data means that the model contains ‘bare bones’ control variables; in other words, the variables are standard demographic and attitudinal variables. For each model, I include trust in the other Parliament. For instance, the model for trust in the Scottish Parliament includes trust in the UK Parliament as a predictor. This aims to get at the ‘congruence’ argument outlined in the previous sections. The models include two attitudinal variables to get at the identity theory: questions of national identity (Scottish or British) and of Scottish independence (Independent or with the UK). I also include left-right scale (continuous), age (centred), political interest, education, income and gender (dummy variables). Whilst this is a bare bones model, it is not dissimilar to related analyses (e.g Harteveld et al, 2013).

Results

Figure 2 below plots the key dependent variables over time on their original scales. What we see immediately is the fundamental expectation of trust in multilevel systems: the more local level is more trusted than the national level. Moreover, we see they are largely stable over time, and they are congruent: when one increases, as does the other. This relationship however changes in 2010/11, and a zero-sum logic seems to be at work; in other words, a negative relationship.

Figure 2 - Mean Trust in UK and Scottish Parliaments, 1999-2015

Moving on to the explanatory analysis, Table 1 shows the full models for both dependent variables with the coefficients in log-odds, and therefore not substantively interpretable. Models which show the stepwise inclusion of variables are in the Appendix. Focusing on the key variables of interest, it shows that trust in the other level’s Parliament is a strong and statistically significant predictor, giving yet more strong evidence in favour of the congruence argument: trust is largely congruent regardless of the level. Interestingly, the usual reason given for this is a lack of information, and so individuals just generalise from the first-order (national) level. In the case of Scotland, this is implausible. The conclusion drawn from this is rather that trust is more general: one either trusts or doesn’t, and this is independent of the actual level.

Looking at the coefficients on ‘Scottish identity’, there are similarly interesting results for the identity argument. Typically, this approach argues that identity creates trust for a particular level, though evidence so far is slim. The results here suggest a different

dynamic: it doesn’t generate trust at the level which is identified with, but rather distrust at the opposing level. Having a Scottish identity doesn’t make an individual trust the Scottish level but rather distrust the UK level. Meanwhile, having a British identity seems unrelated. The interpretation from this is that creating an identity, at least in this case, is divisive.

We can also see the effect of partisanships of other parties. Labour Party partisans are more likely to trust both Parliaments, whilst Conservative Party identifiers are more likely to trust the UK Parliament but less likely to trust the Scottish Parliament, though this only reaches tentative levels of significance. The reverse is true for Liberal Democrat partisans.

However, the model does not allow for substantive, easy interpretation, given the coefficients being in log-odds and interactions present. In order to get a grip on the substantive importance of these coefficients and makes a judgement on the hypotheses, Figure 3 presents average marginal effects (AMEs) on the probability scale for all variables in the model. This is essentially equivalent in interpretation to the coefficient in a linear regression model: it shows the effect on the dependent variable from a one-unit change in one of the independent variables (Cameron and Trivedi, 2010, p343). In this case, all other observations are at observed values, retaining full information for that given observation (rather than holding all other variables at their means). It also shows the conditional marginal effect of SNP partisanship i.e the effect of partisanship conditional on who the incumbent is.

Table 1 - Full models predicting trust in Scottish and UK Parliaments

Scottish Parliament UK Parliament

Trust UK Parliament1.17***

(0.069)Trust Scottish Parliament 1.19***

(0.069)Female -0.10+ -0.28***

(0.054) (0.061)Age (centred) -0.077*** -0.063**

(0.018) (0.021)Medium Income 0.028 -0.16*

(0.062) (0.074)High Income 0.10 -0.20*

(0.086) (0.097)Middle Education 0.24*** -0.46***

(0.070) (0.083)Degree Education 0.64*** -0.59***

(0.098) (0.11)Medium Political Interest 0.20** -0.046

(0.065) (0.077)High Political Interest 0.24*** 0.12

(0.071) (0.081)Scottish Identity 0.11+ -0.71***

(0.063) (0.068)British Identity -0.12 0.20*

(0.098) (0.096)Left-Right 0.080* 0.33***

(0.041) (0.044)Independence (Pro) 0.32*** -0.71***

(0.064) (0.084)Labour Party ID 0.41*** 0.49***

(0.074) (0.088)Conservative Party ID -0.16+ 0.53***

(0.098) (0.11)Liberal Democracy Party ID 0.48*** 0.22+

(0.12) (0.13)SNP Party ID 0.090 -0.27

(0.12) (0.18)Incumbent Scotland (SNP) 0.15+ 0.46***

(0.083) (0.090)SNP ID * Incumbent

Scotland0.84*** -0.32

(0.18) (0.24)Incumbent UK (Conservative) -0.28*** -0.089

(0.081) (0.085)SNP ID * Incumbent UK 0.64*** -0.12

(0.18) (0.21)N 9736 9736Pseudo R2 0.09 14.2

Standard errors in parentheses+ p < 0.10, * p < 0.05, ** p < 0.01, *** p < 0.001

The left-hand panel is the model for trust in the Scottish parliament, whilst the right-hand panel is the model for trust in the UK parliament. The first seven rows provide the effects of interest. In support of H1a, if an individual is a partisan of the SNP, this increases the probability of trusting the Scottish Parliament, by a substantively important 15%; meanwhile, in support of H1b, it decreases the probability of trusting the UK Parliament by 10%. Based on this, we can conclude that SNP partisanship matters for trust at both levels of the political system. However, hidden behind this effect are the conditional effects of partisanship on incumbency (H2). In support of H2a, the probability of trusting the Scottish Parliament increases for SNP partisans if the SNP hold the incumbency: the probability is about 14% higher than when the SNP are not the incumbent and 5% higher than the overall effect of SNP partisanship (i.e, not taking into account incumbency). In support of H2b, and against H2c, there is no effect of incumbency on trust in the UK Parliament: the probability of trusting the UK Parliament is lower for SNP partisans independent of who the incumbent is. However, there is an unexpected spill-over effect. Whilst UK incumbency doesn’t matter for trust at the UK level, it does matter for trust at the Scottish level. When the Conservatives are the incumbent at the UK level, SNP partisans are more likely to trust the Scottish Parliament than if Labour are the UK incumbent. How to explain this? In the theory outlined above, it may be that the SNP do not become more negative to the UK level, but rather see the Conservative government as a threat to the integrity of the Scottish level. There is perhaps, rather, a ‘rally-round-the-flag’ effect at the Scottish level.

Figure 3 - Average Marginal Effect plots for models in Table 1

Robustness

These results are robust to a range of alternative specifications, both statistically and theoretically. Theoretically, I included evaluations of the economy. This was a significant predictor, but did not change the relationship under study and limited the number of years and observations. I also included a survey item that asked ‘who benefits from the economy, Scotland or England?’ to capture whether it was a matter of

perceived underlying disparity, but this also did not change the effects. Since election years show a ‘bounce’ in political trust in general, I controlled for this to see whether the results were being driven simply by election years, but this was not the case. Similarly, I limited the years to before 2014 to make sure that the results were not driven by the post-independence referendum 2015, which also made no difference. Statistically, I included robust standard errors clustered on years, which did not change the point estimates but increased confidence intervals slightly. I included non-partisans, which increased confidence intervals drastically, but the point estimates and significance levels stayed the same, so left them out as the theoretical focus is on partisans. I also expressed the results in a variety of ways, such as odds-ratio, which have slightly different substantive meanings. The results across all of these alternative specifications stayed the same.

A strong claim could be made for endogeneity between SNP partisanship and identity, where one may argue that Scottish identifiers will align with the SNP, and it is identity that matters, this is just channelled through partisanship. This is particularly potent given Models 2 and 6 in the Appendix show a strong coefficient on identity before partisanship is added. Whilst it is true that most SNP identifiers also have a Scottish identity, it is not true that most of those with a Scottish identity are SNP identifiers. In fact, more Scottish identifiers are partisans of the Labour Party (34% to 29%). This is particularly interesting since Labour partisanship has a positive effect on trust at both levels. This suggests it is not (just) identity, though that cannot be ruled out, but partisanship.

It should be made explicit that there are a number of question-wording changes throughout the time series. In particular, in 2010, the questions become different for each level, with the Scottish indicator asking ‘… have Scotland’s best interests at heart’ and the UK indicator asking ‘… have Scotland’s best long-term interests at heart’ (emphasis added). Analysis of the changes shows that this makes little or no difference: Factor analysis shows they form the same scale. I also ran a regression in each year before and after (2009, 2010, 2011) which showed the relationship did not change in 2010, but in 2011, when the question wording stays the same. This is also when the SNP gain a majority, which explains why the relationship changed – party identification with the SNP doubled from 17% to 33%.

Discussion

How does political trust operate in a multilevel system? It was argued that this is under-theorised and relies too heavily on theoretical models which do not integrate the multilevel system directly. Moreover, they tend to rely on the assumption that the first-order (national) arena matters the most, and that effects ‘spill-over’ from that level to the rest of the multilevel system. This paper proposes the mechanism of partisanship. Parties provide a link to the political system(s), and can generate trust and distrust in a political system depending on the cues they provide. In a multilevel system, these cues may differ, and therefore parties may generate trust or distrust at differing levels. This, it is argued, depends in part on incumbency. Here, we have focused on the SNP. However, as shown in the Appendix, the results are similar for both Labour and Conservative party identifiers. Collectively, the results provide strong evidence for this argument; in the models above, partisanship and incumbency are as strong predictors

as trust in the second level. Partisanship matters, and how much it matters depends on incumbency. However, its relationship with incumbency is more nuanced: it matters for trust in the Scottish level, but not for the UK level. Why this discrepancy exists is touched on in the final paragraph, but in general requires further research.

Despite the strong results of the proposed theoretical link, there are also interesting results for identity and congruence, two competing arguments outlined at the start. Congruence matters a lot, and this is probably due to a general trusting outlook rather than information, which is the primary argument in the multi-level trust literature, since the Scottish level is so salient. Secondly, identity matters, but in unexpected ways. It doesn’t generate trust, as the literature expects, but rather distrust. I would hesitate to say this would be a consistent finding in other contexts.

Is this more broadly generalizable beyond Scotland and the UK? The time period is surely unique: a long history of progressive devolution, a successful regional (independence) party, highly salient elections, and so on. It is unlikely to generalise to very different multilevel systems which lack these key features, but it may well be generalizable to similar systems like Bavaria and, at least until recently, Catalonia (Johns, 2017).

Why might the effect of incumbency vary between levels? It may be that the cues the party provides are different: it is about the Scottish level, not the UK level. But there may be a more radical argument. It may well be that, for SNP partisans, the Scottish level is the first-order arena (Johns, 2017). It matters more than the UK level. This may be why the reverse pattern is found for Labour and Conservative partisans: incumbency matters at the UK level but not the Scottish level. This, however, needs much more research.

Appendix

The below table provides stepwise models for the dependent variables: Trust in the Scottish Parliament (models 1-4) and UK Parliament (5-8). The first model includes general demographics, the second model includes attitudinal variables, the third includes party ID, and the final includes interactions with incumbency. The main thing to take from this is looking at the coefficient on SNP ID in Models 4-5, which shows that the inclusion of incumbency turns a previously highly significant, strong predictor to insignificant.

Table 2 - Stepwise variable inclusion for trust in Scottish and UK Parliaments

Scottish Parliament UK Parliament(1) (2) (3) (4) (5) (6) (7) (8)

Trust UK Parliament 1.13*** 1.13*** 1.17*** 1.17***

(0.056) (0.068) (0.069) (0.069)Trust Scottish Parliament 1.13*** 1.15*** 1.19*** 1.19***

(0.056) (0.068) (0.069) (0.069)Female -0.075+ -0.10* -0.10+ -0.10+ -0.18*** -0.26*** -0.28*** -0.28***

(0.043) (0.052) (0.053) (0.054) (0.046) (0.060) (0.061) (0.061)Age (centred) -0.098*** -0.061*** -0.067*** -0.077*** 0.0038 -0.043* -0.058** -0.063**

(0.014) (0.017) (0.018) (0.018) (0.016) (0.021) (0.021) (0.021)Medium Income -0.021 0.048 0.023 0.028 -0.042 -0.16* -0.16* -0.16*

(0.049) (0.060) (0.061) (0.062) (0.054) (0.072) (0.074) (0.074)High Income 0.087 0.10 0.090 0.10 0.047 -0.20* -0.23* -0.20*

(0.069) (0.083) (0.086) (0.086) (0.071) (0.094) (0.096) (0.097)Middle Education 0.059 0.26*** 0.27*** 0.24*** -0.29*** -0.43*** -0.42*** -0.46***

(0.054) (0.067) (0.069) (0.070) (0.059) (0.081) (0.082) (0.083)Degree Education 0.39*** 0.68*** 0.69*** 0.64*** -0.14+ -0.55*** -0.54*** -0.59***

(0.078) (0.095) (0.097) (0.098) (0.081) (0.11) (0.11) (0.11)Medium Political Interest 0.37*** 0.36*** 0.27*** 0.24*** 0.096 0.19* 0.14+ 0.12

(0.056) (0.067) (0.070) (0.071) (0.061) (0.079) (0.081) (0.081)High Political Interest 0.34*** 0.31*** 0.20** 0.20** 0.0100 -0.021 -0.045 -0.046

(0.050) (0.062) (0.065) (0.065) (0.056) (0.075) (0.076) (0.077)Scottish Identity 0.21*** 0.11+ 0.11+ -0.79*** -0.74*** -0.71***

(0.060) (0.062) (0.063) (0.066) (0.068) (0.068)British Identity -0.21* -0.14 -0.12 0.25** 0.21* 0.20*

(0.094) (0.097) (0.098) (0.093) (0.096) (0.096)Left-Right -0.0045 0.071+ 0.080* 0.37*** 0.33*** 0.33***

(0.037) (0.040) (0.041) (0.041) (0.043) (0.044)Independence (Pro) 0.51*** 0.32*** 0.32*** -1.00*** -0.73*** -0.71***

(0.059) (0.063) (0.064) (0.078) (0.084) (0.084)Labour Party ID 0.41*** 0.41*** 0.43*** 0.49***

(0.073) (0.074) (0.087) (0.088)Conservative Party ID -0.17+ -0.16+ 0.47*** 0.53***

(0.097) (0.098) (0.11) (0.11)Liberal Democracy Party ID 0.48*** 0.48*** 0.15 0.22+

(0.12) (0.12) (0.13) (0.13)SNP Party ID 0.96*** 0.090 -0.59*** -0.27

(0.083) (0.12) (0.11) (0.18)Incumbent Scotland (SNP) 0.15+ 0.46***

(0.083) (0.090)SNP ID * Incumbent Scotland 0.84*** -0.32

(0.18) (0.24)Incumbent UK (Conservative) -0.28*** -0.089

(0.081) (0.085)

SNP ID * Incumbent UK 0.64*** -0.12(0.18) (0.21)

N 14414 9884 9736 9736 14414 9884 9736 9736Pseudo R2 0.052 0.058 0.076 0.094 0.043 0.12 0.138 0.142

Standard errors in parentheses+ p < 0.10, * p < 0.05, ** p < 0.01, *** p < 0.001

The AME plots below present the same models, but focusing on Labour and Conservative partisanships. We find similar effects of partisanship, but different effects for incumbency. Incumbency matters at the national level, but not the Scottish level.

Table 3 - Average Marginal Effect plots for Labour partisans

Figure 4 - Average Marginal Effect plots for Conservative partisans