Theoretical framework

The literature on parties' long- and short-term goals focuses on three such goals: winning votes, gaining office and implementing policy (Müller and Strøm Reference Müller and Strøm1999), put into practice as vote-seeking, office-seeking and policy-seeking behaviours.Footnote ³ Navigating between these sometimes opposing and sometimes mutually reinforcing goals presents a parsimonious framework through which the strategic action of parties can be fruitfully analysed. Even if vote-seeking behaviour is credibly assumed to be instrumental in character by default, it is nevertheless of crucial importance to all parliamentary parties. Winning votes is a prerequisite for winning seats, which in turn is (often) a prerequisite for gaining office, and – depending on the institutional setting – implementing policy. A key component in trying to attract votes is to present a policy profile that (partly) serves this purpose, and consists of the sum of a party's policy positions.

Research on the behaviour of political parties as strategic actors regarding their policy positioning has predominantly been concerned with parties' reactions to environmental developments, such as changes in public opinion and vote losses. A key question is how parties respond in their positioning to shifts in public opinion on the one hand and realized vote losses on the other under conditions of incomplete information. In a recent review article, Andreas Fagerholm (Reference Fagerholm2016) notes that the research on party policy change provides ample, if varied, evidence that parties respond to changes in their surrounding political environment, including the positions of other parties, by adjusting their policy positions. Notably absent, however, is how parties relate to coalitions of other parties.

The literature on coalition politics stresses that more ideologically cohesive coalition governments are likelier to form than those that are less ideologically cohesive (e.g. Bäck and Dumont Reference Bäck and Dumont2008; Martin and Stevenson Reference Martin and Stevenson2001, Reference Martin and Stevenson2010), and that ideological proximity is also a factor in bargaining duration (Martin and Vanberg Reference Martin and Vanberg2003) and government survival (Warwick Reference Warwick1994). Tendencies towards greater party-system fragmentation and increasingly salient second (and possibly third) dimensions complicate matters for government formation, as they potentially open up the party system for new parties that exploit previously neglected issues to win votes (Bakker et al. Reference Bakker2020b). The presence of more parties in parliament typically results in a more fragmented and complex bargaining environment, with consequences such as increased bargaining duration (De Winter and Dumont Reference De Winter, Dumont, Strøm, Müller and Bergman2008; Diermeier and Van Roozendaal Reference Diermeier and Van Roozendaal1998; Golder Reference Golder2006, Reference Golder2010; Martin and Vanberg Reference Martin and Vanberg2003). Introducing additional dimensions of conflict might also introduce conflict among previous coalition partners, as there is no guarantee that they are ex ante aligned on all now-salient dimensions. Given that parties appear to prefer ideologically more compact and connected coalitions than the alternatives, when possible (see e.g. Pellikaan et al. Reference Pellikaan, de Lange and van der Meer2018 for an example where this preference breaks down), it follows that adjusting policy positions should affect parties' ‘coalitionability’. Such adjustment can primarily occur through adopting specific policy stances, or through focusing on specific policies while avoiding others, or a combination of both approaches.

Spatial theory (e.g. Downs Reference Downs1957, as an early and particularly influential account) provides an approach focusing on parties' strategic positioning in policy space; salience theory (Budge and Farlie Reference Budge and Farlie1983; Robertson Reference Robertson1976) instead focuses on how parties emphasize issues in a strategic manner. A more recent development is to consider the positional and salience approaches as complementary rather than competitive (Elias et al. Reference Elias, Szöcsik and Zuber2015). Parties do not necessarily value all dimensions and their constituent issues as equally important, and it is therefore likely that they will approach different dimensions based on party-specific factors, and use different strategies as a consequence. These strategies are, though, primarily concerned with parties' relation to voters. From the perspective of coalition bargaining, their implications are different. For example, a so-called blurring strategy is deployed to capture a broader spectrum of voters on a dimension than if the party's position was clear (Rovny Reference Rovny2013). However, this may also have adverse consequences on coalition formation, as it would also be unclear to potential coalition partners what policies the party pursued.

A blurring strategy can be augmented by simultaneously decreasing the focus on a ‘blurred’ dimension, thereby signalling that it is of lesser importance to the party. This can be considered a secondary, coalition-facing strategy. This kind of strategy can be pursued through parties either adjusting their position on specific issues, or adjusting the salience accorded to different issues – what Thomas Meyer and Markus Wagner (Reference Meyer and Wagner2019) have referred to as opinion-based policy change and emphasis-based policy change, respectively. However, these two options are not qualitatively equivalent. Staking out positions means that these positions can at any subsequent point be compared to the policy record of any government the party is or has been a part of. A party that adjusts its positions in anticipation of joining a government coalition could thus try to mitigate this potential threat of drifting away from their policy brand – its unique combination of policy proposals – as perceived by the electorate, essentially anticipating areas of compromise in advance of joining the coalition. The alternative is for parties to focus selectively on issues and issue dimensions in a way that facilitates greater coalition compatibility, either by focusing on the same issues as those favoured by the coalition or by having issue foci that are tangential (Ecker and Meyer Reference Ecker and Meyer2017; Falcó-Gimeno Reference Falcó-Gimeno2014; Luebbert Reference Luebbert1986), while avoiding issues that are likely to lead to friction (and compromise) in a coalition. This is simpler than adjusting positions, and there is already evidence that parties avoid issues that are contentious within the party in election campaigns (see e.g. Steiner and Mader Reference Steiner and Mader2019), and between coalition partners outside of the pre-electoral period (Sagarzazu and Klüver Reference Sagarzazu and Klüver2017; see also Martin and Vanberg Reference Martin and Vanberg2008).

Against the argument that parties take account of the coalitional implications of their issue focus is the fact that the parliamentary situation facing parties ahead of coalition negotiations is ultimately decided by their ability to attract voters. Moreover, when parties attempt to realize their policy goals through a coalition government, compromise between the constituent parties becomes necessary, which can prove risky for the party's individual policy brand come the next election (Fortunato Reference Fortunato2019, Reference Fortunato2021; Martin and Vanberg Reference Martin and Vanberg2011; Plescia et al. Reference Plescia, Ecker and Meyer2022). To a certain extent, parties are required to consider voters ahead of coalitions. Failing to win enough votes precludes parliamentary membership altogether, and having too few seats means a weaker bargaining position during coalition negotiations. Both should make joining a government coalition less likely, all else being equal.

I argue that the prevailing logic guiding coalition-anticipating strategies is one of mitigating the potential costs of joining a coalition government while simultaneously improving coalitionability at the margins. The central problem facing parties entering coalition governments is how to maximize policy influence in the coalition while maintaining their policy brand. Individual parties can mitigate deviations from their policy brand and streamline compromise processes through strategically focusing on issues that are simultaneously central to their policy brand and compatible with potential coalitions. By narrowly focusing on such a set of issues, parties can avoid failing to implement (central) policy pledges and moreover are more likely to implement what policy pledges they have made. This, however, obviously entails that the set of issues that is downplayed is both sufficiently important to other parties in the party system, while also not being of crucial importance to the party and its voters in the first place. The expectation is therefore that parties will adjust the salience of issues belonging to their secondary dimension, while maintaining a similar focus on their primary dimension, all else being equal. While this is most likely an ongoing process during the entire electoral cycle, it should be most pronounced in what can roughly be considered the election campaign period, especially so for government incumbents (Sagarzazu and Klüver Reference Sagarzazu and Klüver2017), finalized in the publication of an election manifesto or its equivalent.

The proposed strategy has two desirable properties for a would-be coalition member: it makes it more likely that the party will be included in a coalition due to perceived compatibility, and it also decreases the number of issues that require compromise on publicly stated positions. What ultimately determines whether a party adopts a salience adjustment strategy or not is based on the potential benefits such a strategy can yield in terms of office and policy gains while keeping vote losses at a minimum. While office gains are inextricably linked to joining a government coalition, policy gains can be achieved outside the government coalition, depending on institutional arrangements (Strøm Reference Strøm1990). Hence, a party's self-estimated likelihood of joining a given coalition (or any coalition) is of crucial importance.

Coalition inclusion and strategic action

While one component of a party's likelihood of being a member of a coalition is its choice of strategy, it is not the only one. The ideological character of a potential cabinet contributes to its likelihood of being formed as well (Kayser et al. Reference Kayser, Orlowski and Rehmert2022; Martin and Stevenson Reference Martin and Stevenson2001, Reference Martin and Stevenson2010). It would therefore be reasonable that a potential cabinet's ideological position is also of relevance to the choice of strategy by its potential members. Specifically, I assume that parties will make strategic choices with respect to the likeliest coalition. If the party is close to this coalition in policy space, there is little to be gained in terms of coalitionability from adjusting salience. Inversely, if the party is distant, it is expected that the salience reduction strategy is more fruitful, as a reduction in salience of an issue could give the impression of a closer proximity in policy space than under previous levels of salience. However, both are conditional on the likelihood of joining any coalition. It is of little use to adjust the salience of a policy if it is either unlikely to make coalition membership sufficiently more likely to the point where losses elsewhere are offset, or if the party is already in a sufficiently strong bargaining position. In brief, then, parties in a (very) weak or (very) strong bargaining position have little need to adjust their issue salience with respect to improving coalition opportunities. However, as discussed previously, parties that are members of a coalition also need to maintain their own policy brand. Parties in a very strong bargaining position can be expected to have a greater leeway in seeking to differentiate themselves from their coalition partners in this respect. Even if they focus on issues that may be contentious within the coalition, their strong bargaining position makes it difficult to exclude them, and they therefore enjoy a strategically privileged position. While this is not likely to affect the behaviour of parties in a strong bargaining position when they are distant from their likeliest coalition (possibly already a consequence of a diverging policy agenda), those in close proximity can adjust the salience of their secondary dimension upwards in an attempt to strengthen their policy brand relative to their closest peers.

Parties in close proximity to their likeliest coalition and with intermediate bargaining strength find themselves in a precarious situation. Attempting to reduce salience of an issue in order to join a coalition is likely to be damaging to their policy brand, to the extent that the secondary dimension is already sufficiently salient. Parties need to maintain some form of distinction from their closest peers, or potential voters may find little reason to vote for one party over the other based on their policy proposals. Lowering the salience of a dimension that provides such a distinction could therefore be costly. Hence, we should expect these parties to increase the salience of their secondary dimension to maintain policy brand integrity, which may help retain previous voters and potentially attract new ones. While this may induce some degree of risk due to the potential for unsightly compromises, again, the close proximity means that such compromises are more likely to be minor than if the party were distant. Moreover, given the parties' already close proximity, they are unlikely to improve their chances of joining the coalition by reducing the salience of their secondary dimension.

Parties that are distant from their likeliest coalition face a different opportunity structure. Given that they are distant, reducing the salience of their secondary dimension may, as already mentioned, give the impression that they are closer in policy space to the other potential coalition members, or make them more compatible if the distance is due to their secondary dimension. Either way, we should therefore expect parties with an intermediate bargaining strength to reduce the salience of their secondary dimension when they are distant.

The expected behaviour from parties according to their proximity to their likeliest coalition and their bargaining strength is summarized in Table 1. Status quo here refers only to coalition-anticipating salience adjustment strategies, and not to any strategies that predate the coalition-anticipating strategies. For example, a party that chooses to focus more on its secondary issues to attract voters with no subsequent adjustments to improve coalitionability is considered to pursue a status quo strategy.

Table 1. Expected Strategies Based on Coalition Proximity and Coalition Inclusion Probability

Following from the preceding section, the central hypothesis of the article can be stated as follows, with the caveat that it is expected to apply primarily to mainstream parties:

Hypothesis 1: As the distance from the likeliest coalition increases/decreases, a given party with intermediate bargaining strength is more likely to follow a salience reduction/increase strategy for secondary dimensions/issues.

The hypothesis reflects the expected effect of distance in concert with the conditional effect of bargaining strength. Parties that are distant from their likeliest potential coalition can improve their chances of joining it by strategically reducing salience of their secondary dimension, while parties that are proximate to their likeliest potential coalition can stave off potential vote losses by attenuating their particular policy brand in comparison to their proximate peers by increasing the salience of their secondary dimension. Both are conditional on the associated expected costs of adjusting secondary-dimension salience – primarily vote losses, albeit through different mechanisms depending on whether salience is reduced (fewer votes attracted due to positions on the secondary dimension) or increased (loss of votes due to policy compromises reached relating to secondary dimension issues) – which are only sufficiently offset by office and/or policy gains under conditions of intermediate bargaining strength.

Data and methods

To investigate the hypothesis I use panel data, drawing on three different data sources that in concert contain data on historical government formations and coalitions, post-electoral parliamentary parties, policy positions and salience.

Data on governments and their coalitions, the number of seats, pre-electoral coalitions and parties in parliament are retrieved from the Party Government in Europe Database (Bergman et al. Reference Bergman, Ilonszki and Müller2019, Reference Bergman, Bäck and Hellström2021; Hellström et al. Reference Hellström, Bergman and Bäck2021), henceforth referred to as PAGED. In total, these data contain information on government formations between 1944 and 2019, with varying start and stop dates on a per-country basis. The data are restructured to be stacked on parties and nested in government formations. Only parties that have been elected to parliament for at least two consecutive elections are included in all the analyses.Footnote ⁵

I focus my analysis on the election-proximate period – that is, the pre-electoral and post-electoral periods. Parties produce their election manifestos or some equivalent during the pre-electoral period in concert with election campaigns, and parties that are already members of government coalitions have their strongest incentive to differentiate themselves from their coalition partners during this period as well (Sagarzazu and Klüver Reference Sagarzazu and Klüver2017). Additionally, parties in government can be expected to be punished for defecting from their prior election pledges while still in government (Matthieß Reference Matthieß2020). I use contemporaneous data on party positions and salience as we can reasonably assume that parties will make their adjustments based on prospective coalitions, rather than their historical analogues. That parties can reasonably infer the current policy stances and foci of other parties, alongside voters, is a necessary condition for election campaigning to function in the first place. During the immediate post-electoral period, parties then enter some coalition bargaining process if no single party has gained a majority.

To calculate the distance to potential coalitions, there are two primary options available. The first is to rely on data from the Manifesto Project, henceforth referred to as the Manifesto data or MARPOR (Volkens et al. Reference Volkens2020), which gives access to impressive time series. The second option is the Chapel Hill Expert Surveys (CHES) data on party positions (Bakker et al. Reference Bakker2015, Reference Bakker2020a; Polk et al. Reference Polk2017). While the time series are notably shorter than in the Manifesto data, CHES crucially includes data on multiple scales (dimensions) for the entire period of observation, in full covering the last election before the first survey in 1999 until the last election before the latest survey in 2019. In this article, I test the hypothesis using both sets of data but with the same underlying model. Drawing on the scales used in the CHES data, the first dimension corresponds to the left–right economic scale, while the second dimension corresponds to the so-called Green, Alternative, Libertarian–Traditional, Authoritarian, Nationalist scale, or GAL–TAN. To facilitate comparison with the positions derived from the Manifesto data, I attach categories to the two different scales following the ones suggested by Christopher Prosser (Reference Prosser2014) for the comparable left–right economic and sociocultural dimensions. To calculate the positions from the Manifesto data, I use the logit-based scaling method suggested by Will Lowe et al. (Reference Lowe2011).

The use of CHES and MARPOR data to calculate positions by necessity introduces limitations on which parties and government formation opportunities from the PAGED data can be used in the analysis, both in terms of temporal coverage due to the time series available, and also which parties have been coded in the respective sets of data. I proceed with three subsets of data in the subsequent analysis. A first subset includes all observations beginning with the first post-electoral government formation opportunity after 1970 and uses MARPOR to calculate party positions. A second subset includes all observations, beginning with the first post-electoral government formation opportunity where CHES data are available. Finally, a third subset uses MARPOR data to calculate party positions but matches the formation opportunities to the same ones as in the CHES subset.

To measure dimensional salience, I again turn to the Manifesto data.Footnote ⁶ Salience is measured as the proportion of a text that is focused on policy categories associated with the left–right economic and GAL–TAN scales.Footnote ⁷ To facilitate comparison with the positional data in CHES, categories in the MARPOR data have been attached to each of the two dimensions drawn from the CHES data. I use the log salience measure proposed by Prosser (Reference Prosser2014: 96), which leverages the advantages of a log-based approach (see Lowe et al. Reference Lowe2011) while simultaneously producing an easily interpretable measure, ranging between 0 and 1. The measure is calculated as:

$$Salience = \displaystyle{{{\rm log}( {N\;{\rm quasi{\hbox-}}{\rm sentences\;}\;with\;relevant\;codes + 1} ) } \over {{\rm log}( {N\;total\;{\rm quasi}{\hbox-}{\rm sentences} + 1} ) }}$$

The secondary dimension is determined as whichever dimension between the left–right economic and GAL–TAN dimensions has the highest salience score. In the case of ties, whichever is the secondary dimension for most parties in the party system at the present formation opportunity is determined to be the secondary dimension. It is, however, important to acknowledge potential problems with this approach. Given that dimensions are constituted of multiple individual issues, it may very well be the case that parties have a set of core issues belonging to one dimension, but in aggregate give greater emphasis to issues belonging to another dimension. While this may be unlikely given the theoretical rationale behind dimensions – that they are aggregations of bundles of issues where parties tend to hold correlated positions – it is nevertheless something to take into account when analysing the results.

There are two key independent variables (or rather, the interaction between the two is key): distance from the likeliest winning or almost-winning coalition including the party and bargaining strength, the latter represented by the gross CIP for a given party.Footnote ⁸

The first variable retrieves the likeliest potential coalition, understood as having the highest predicted response rate from the CIP conditional logit model that satisfies one of two different sets of criteria. The first set of criteria is that it is winning, understood as the coalition members controlling 50% + 1 seats, and that it includes the current party. The second set of criteria is that the potential coalition is not winning and does not include the current party but would be winning if it did include the current party. The distance to this coalition's weighted mean position, the weight being coalition seat share, is then measured as the two-dimensional Euclidean distance between the party's position and the weighted mean position of the coalition.

Gross CIP is a measure produced by the conditional logit model discussed above. It is, quite simply, the sum of predicted probabilities for a given party and all possible governments for a given formation opportunity, and as such it has a theoretical range of [0,1]. To facilitate a more straightforward comparison to the different distance measures, the gross CIP measure is linearly transformed to a range of [0,10], corresponding to the same approximate observed range as the distance measurements.Footnote ⁹ Additionally the gross CIP measure is also squared, as the expected pattern is non-linear with less tendency towards adjusting secondary dimension salience among parties with low or high gross CIP.

Given that there is a conditional expectation for parties to pursue the strategy, namely that parties with an intermediate gross CIP are those expected to pursue a salience adjustment strategy, two interaction terms are included: one between gross CIP and the distance variable, and one between gross CIP squared and the distance variable. The main term of interest is the latter of the two, given the expected relationship between gross CIP and strategy adoption.

Nicheness is here included as a control, as the theorized strategies are primarily expected for mainstream parties. Niche parties are strongly constrained in their choice of strategy as they primarily compete on issues belonging to a secondary dimension (Adams et al. Reference Adams2006; Meguid Reference Meguid2005, Reference Meguid2008). To measure nicheness, I use the measure developed by Daniel Bischof (Reference Bischof2017), which is a joint measurement of a party's market share and specialization on a set of five issues associated with traditional niche party families. I then construct a dummy variable to indicate if a given party is niche based on the distribution for each country, where a party is determined as niche if its nicheness score is greater than one standard deviation above the mean.Footnote ¹⁰

In addition to nicheness, I also control for membership in a pre-electoral coalition, and if the party is a member of the outgoing government coalition. Pre-electoral coalitions, in which I follow Sona Golder (Reference Golder2006) and include both pre-electoral coalitions and electoral alliances, bring to the fore the one-sided salience adjustments discussed above, as the constituent parties of a pre-electoral coalition publicly commit to some form of policy coordination. We should largely expect similar patterns to those in the salience adjustment strategies, but with respect to the pre-electoral coalition itself. As a final control, I also include the government incumbency status of the party. Incumbent status is expected to have a moderating effect, even though, as already discussed above, the pre-electoral period represents one of the best opportunities for government parties to present a policy programme distinct from its government compatriots. Further controls include the prospective seat share of the party – that is, its post-election seat shareFootnote ¹¹ – and its general left–right position, corresponding to the general left–right scale for the CHES data subset and the general left–right scale proposed by Prosser (Reference Prosser2014) for the MARPOR data subsets (Table 2).

Table 2. Descriptive Statistics

Note: The number of observations refers to the total number of combinations of parties and formation attempts.

Empirical analysis

To conduct the analysis, the following (simplified) model is specified:

$$\eqalign{& Multidimensional\;model\colon \;Salience\;of\;secondary\;dimension \cr & \quad = \beta _1[ {Lag( 1 ) \;Salience\;of\;secondary\;dimension} ] + \beta _2[ {Gross\;CIP} ] \cr & \quad + \beta _3[ {Gross\;CIP^2} ] + \beta _4[ {Distance\;from\;weighted\;mean\;coalition\;position} ] \cr & \quad + \beta _5[ {Gross\;CIP\;\times \;Distance\;from\;weighted\;mean\;coalition\;position} ] \cr & \quad + \beta _6[ {Gross\;CIP^2 \times \;Distance\;from\;weighted\;mean\;coalition\;position} ] \cr & \quad + \beta _7[ {Niche\;party} ] + \beta _8[ {Pre \hbox{-} electoral\;coaltion\;member} ] + \beta _9[ {Incumbency} ] \cr & \quad + \beta _{10}[ {Seat\;share} ] + \beta _{11}[ {General\;left{\rm \ndash }right\;position} ] } $$

β ₂ through β ₁₁ correspond to the independent variables introduced in the previous section. β ₁, however, corresponds to a theoretical expectation that parties adjust their issue focus with reference to previous positions (see e.g. Adams Reference Adams2001; Budge Reference Budge1994) and/or issue foci. Given this expectation, a once-lagged version of the dependent variable is included in each model. The terms that are most central to the hypotheses are β ₅ and β ₆, as these correspond to the expected conditional relationship between gross CIP (terms β ₂ and β ₃) and distance from the weighted mean coalition (term β ₄). The model is estimated on each of the three data subsets discussed above.

To estimate the model, I use a system generalized method of moment (GMM) estimator (Blundell and Bond Reference Blundell and Bond1998) to contravene the issue of so-called Nickell bias (Nickell Reference Nickell1981)Footnote ¹² that is otherwise present when estimating a dynamic model with fixed effects. When estimating a model using system GMM, determining the relationship between each regressor and the error term is necessary, as it determines which lags can be used as valid instruments (Kiviet Reference Kiviet2020: 6–8). Distance from the likeliest coalition is treated as a strictly exogenous variable, as its construction involves a separate process that is unrelated to the salience of the secondary dimension, and hence is expected to be uncorrelated with the error term. The remaining regressors, excepting the lagged dependent variable, which is by necessity endogenous, are treated as predetermined variables.Footnote ¹³ The model is estimated using the user-created command xtabond2 (Roodman Reference Roodman2009) in Stata. The instrument matrix is collapsed to avoid unnecessarily inflating the number of instruments.