Direct (Executive) Effects

Regarding the novel element of our model, the direct effect represented by arrow ①, Bartolini (Reference Bartolini1984, 277) noted early on that party interaction in the electoral and legislative arenas might be affected by party interactions during presidential elections because of the ‘double electoral process’ of semi-presidential regimes. While he did not develop this idea much further, two arguments suggest why presidential elections might have a destabilizing effect on party interactions during government formation, reducing its predictability and, consequently, making party systems more open (Mair Reference Mair1997).

To map out these arguments, let us begin with a (somewhat stylized) description of the ‘ordinary’ operation of parliamentary government. Cabinets generally result from negotiations between a limited number of parties whose leaders strive to secure the benefits of office, policy, and votes (Müller and Strøm). Majorities tend to reflect left-right logic (or some other policy dimension) or mere ad-hoc compromises (Kellam Reference Kellam2015). Importantly, each party caters to a defined portion of the electorate, and legislators are generally subject to party discipline. For these reasons, the number of possible governing coalitions is limited. Office (leaders, portfolios), policy (coalition agreements) and votes (constituencies) cannot be combined at will.

Now, let us add a presidential arena to the model. To win a presidential race, candidates do not need to follow the conventional lines of party competition. Quite the opposite, they might find it useful, or even necessary, to become more inventive. One reason is that popularly elected presidents face the electorate as a whole; another is the ‘winner-takes-all’ logic of the presidential race. Presidential candidates cannot afford to ignore significant segments of the population as easily as a party would. While parties can focus their campaigns on their support base and negotiate cabinet deals after the results are in, presidential candidates need to build their coalitions well ahead of an election. Moreover, since voters (unlike parties) may hold any imaginable combination of policy preferences, they can be approached via a more diverse set of issues. This generates the potential for formal and informal alliances that go beyond the constraints of existing patterns of party competition and cooperation. The decoupling is further facilitated because legislative and presidential elections in Europe are generally held at different times.

Separate electoral arenas are, however, linked in practice, as the principal-agent literature reminds us (Åberg and Sedelius Reference Åberg and Sedelius2020; Samuels and Shugart Reference Samuels and Shugart2010; Strøm Reference Strøm2000). Presidential candidates do not campaign independently of the party system. Quite the opposite, organizational support is critical, and even personalistic campaigns of outside challengers generally find a party to back them. Since presidential candidates need to appeal to a wider segment of the electorate, broad and unusual coalitions are likely to be formed. These coalitions may include parties that would usually be considered too extreme and/or too small to play a role in executive politics, but ‘one or more of them can plausibly claim to represent the decisive electoral bloc in a close contest and may make demands accordingly’ (Linz Reference Linz1990, 58) – demands that will include a prize that is otherwise unattainable – participation in government – as a reward for support in the presidential election (Freudenreich Reference Freudenreich2016). Overall, while both the legislature and the president have a mandate from the same electorate to control cabinet formation (Schleiter and Morgan-Jones Reference Schleiter and Morgan-Jones2010), these mandates differ systematically, which opens the party system to a greater variety of potential outcomes.

To give an example, the Social Democratic Party (SDP) of Finland gained executive office in 1937 in coalition with the Agrarian Party (SK), after having been excluded since independence in 1917 – just after SDP agreed to support SK's presidential candidate (Kallio), who only came in third at the elections held two months earlier. Similarly, the 2005 governmental coalition between the Bulgarian Socialist Party (BSP) and the Turkish-minority Movement for Rights and Freedoms (DPS), political enemies since the ethnic persecution of the latter by the Communist precursor of the former in the 1980s, has its roots in the 2001 presidential elections when the DPS provided essential electoral support to the BSP's candidate (Parvanov). More recently, in Poland, the electoral coalition between Law and Justice (PiS), Solidarity Poland, and Poland Together, created for the October 2015 legislative elections, originated in the presidential elections five months earlier, when all of them came together to support PiS’ candidate, Duda.

The abovementioned examples illustrate how a president's popular election can affect party competition patterns, either by forming previously unseen cabinet coalitions or by including political forces previously excluded from government. Moreover, because ‘the [presidential] “majority” generated might not represent a politically more or less homogeneous electorate or a real coalition of parties’ (Linz Reference Linz, Linz and Valenzuela1994, 21), and given popularly elected presidents' weaker partisan ties (Samuels and Shugart Reference Samuels and Shugart2010), these alliances of ‘presidential’ parties tend to be fragile and short-lived since policy differences among ideologically heterogeneous member parties are likely to broaden with time. The ‘ordinary’ operation of parliamentary government, where parties occupying different electoral niches form coalitions based on vote shares and ideological proximity, is thus disturbed as the majoritarian character of presidential elections gives the patterns of party interaction a loose and temporary character. Yet large heterogeneous coalitions are sufficiently durable to have a tangible impact on the complexion of the executive (Grotz and Weber Reference Grotz and Weber2012).

Such complications are less relevant in parliamentary republics where, because a qualified majority is usually required, presidents are typically (s)elected either through compromise between the main parliamentary parties (including government and opposition) or by government majority (Strøm Reference Strøm2000). Because this ‘almost compulsory’, collaboration is seen as ad hoc and strictly occasional, the structure of party competition is rarely affected, and the presidential (s)election even tends to exert a ‘positive’ effect in the sense of renewing executive majorities. A clear example can be found in Greece, where all presidents were appointed either with the support of the governing coalition (Tsatsos in 1975, Karamanlis in 1980/1990, Sarzetakis in 1985, Stephanopoulos in 1995) or as a compromise between the two main contending parties (Stephanopoulos in 2000, Papoulias in 2005/2010, Pavlopoulos in 2015). The cartelization of presidential selection reflected a highly stable party system. The same can be said of other parliamentary republics such as Albania, Hungary, Malta, and, until 2014, Turkey.

A second argument, why popular presidential elections can hinder party system closure, derives from the higher status of the office in (semi-)presidential republics compared to parliamentary republics or even monarchies. The very fact of a popular mandate suggests that elected presidents, ‘although initially the choice of a small proportion of the electorate, […] represent a “true and plebiscitary” majority’ (Linz Reference Linz, Linz and Valenzuela1994, 21) and that, consequently, they do not need to respect the ‘usual’ process of coalition formation and party cooperation (Bartolini Reference Bartolini1984; Duverger Reference Duverger1980). On this basis, popularly elected presidents have often used their greater legitimacy and prestige to stretch their influence into the making and breaking of governments and/or parliamentary coalitions (Kang Reference Kang2009). For example, as Sedelius and Ekman point out, ‘by publicly criticising the government […] the president can make it more or less impossible for a prime minister to remain in office’ (Reference Sedelius and Ekman2010, 523). Since the prime minister's performance is a critical expression of party power (Grotz and Weber Reference Grotz, Weber, Harfst, Kubbe and Poguntke2017; Grotz and Weber Reference Grotz and Weber2022), this conclusion concerns the stabilization of parliamentary government as a whole.

A significant event occurred in 1996–7 when Bulgarian president Zhelev refused to invite the ruling BSP to form a new cabinet despite its clear majority in parliament. Instead, he insisted on early assembly elections through media addresses and public speeches (Schleiter and Morgan-Jones 2005). Four years earlier, leaning on his popular mandate, Zhelev had already managed to convince the DPS leaders to join the ex-communist BSP and topple the government formed by his ‘own’ party, the Union of Democratic Forces (Ganev Reference Ganev and Elgie1999). On both occasions, the process of party system stabilization was affected by the president's intervention. Another clear example is Iceland in the late 1950s, when the Social Democrats first formed a minority government, which was almost immediately followed by the creation of a coalition with the centre-right Independence Party, mainly due to presidential ‘pressures’ (Kristinsoon Reference Kristinsoon and Elgie1999).

The head of state can also play an active role during government formation in some constitutional monarchies or parliamentary republics (Schleiter and Morgan-Jones Reference Schleiter and Morgan-Jones2009a). However, because a monarch or indirectly elected president is expected to stand neutrally above the partisan battle, they cannot claim to be ‘tribunes’ of the partisan battle (Baylis Reference Baylis2007, 89). Thus, in countries like Italy, Germany, or even Spain, the head of state will tend to follow the existing patterns of party interaction, strengthening rather than weakening the system of competition as a whole. This is in clear contrast to (semi-)presidential republics, where popular presidential elections produce unpredictability and instability. For all these reasons, we hypothesize:

Institutional Moderators: Presidential Power and the Electoral System

Before we proceed with empirical estimation, this section serves to define the institutional scope conditions of our theory.

First, our argument assumes that an elected president is not purely a figurehead; s/he carries some political clout. Therefore, we expect the effect on party system closure to be stronger when the presidency is powerful.

Once again, a rich literature, inspired by the principal-agent theory, documents negative relationships between presidential power and democratic consolidation (Mainwaring and Shugart Reference Mainwaring and Shugart1997; Shugart and Carey Reference Shugart and Carey1992), cabinet stability (Fernandes and Magalhães Reference Fernandes and Magalhães2016; Protsyk Reference Protsyk2005), electoral fragmentation (Clark and Wittrock Reference Clark and Wittrock2005; Elgie et al. Reference Elgie2014; Golder Reference Golder2006; Hicken and Stoll Reference Hicken and Stoll2013), and party institutionalization (Samuels Reference Samuels2002; Samuels and Shugart Reference Samuels and Shugart2010). Studies of the structure of competition have been fewer. A notable exception is Meleshevich, who concluded that ‘a presidency which occupies a predominant position in a political system and possesses strong political powers is not conducive to the development of a party system’ (Reference Meleshevich2007, 146). This conclusion is based on an association of Russia and Ukraine's strong presidents and weakly institutionalized party systems, in clear contrast to the higher levels of systemic stability in the Baltic states, all with much weaker presidents. The logic is that when presidents, typically ‘outsiders’ without previous governing experience, can unconditionally appoint and/or veto prime ministers and/or ministers, dissolve parliament, and/or veto legislation, party interactions will be under their thumb (Schleiter and Morgen-Jones Reference Schleiter and Morgan-Jones2009c). It is no coincidence that notable cases of presidential interference with government formation occurred in countries with rather powerful presidencies (for example, Louis-Napoléon and De Gaulle in France, Hindenburg in Germany, Wałęsa in Poland, Putin in Russia, Kuchma in Ukraine).

More recently, however, Andrews and Bairett (Reference Andrews and Bairett2014) showed that, at least for post-communist Europe, it is not presidential power per se that negatively affects electoral stability but the combination of popular presidential elections and strong presidencies. For example, the Czechoslovak and Hungarian party systems were stable despite having strong but indirectly elected presidents. In this view, presidential power amplifies elite incentives for political coordination. Similarly, at the legislative level, powerful, popularly elected presidencies would foster the formation of new parliamentary groups or the creation of previously unseen parliamentary coalitions to pass relevant legislation, consequently increasing legislative instability. We expect this pattern to be reflected on the executive level.

Importantly, while H2 describes an interaction, including presidential power as a control variable will also allow us to isolate the effect that comes with popular election.

Besides the power of the head of state, the direct effect of popular presidential elections is likely to be conditioned by the electoral system. In fact, the operation of the electoral system is not just a moderator but a critical element of our theory. The basic distinction is between majority systems (like France) and plurality/Single Transferable Vote (STV) (like Iceland or Ireland).

In plurality systems, the influence of popular presidential elections on party system closure is most obvious. Electoral plurality in a single-round contest may depend on any number of votes, which may be eventually provided by unusual partners – such as in Finland, where ‘the main changes in […] politics have often been made in connection with [plurality] presidential elections’ (Paloheimo Reference Paloheimo and Elgie2001, 93). We thus expect a strong effect in plurality systems.

Regarding majority systems, we need to distinguish between those elections where a majority winner emerged in the first round (as happened in the French Second Republic or the First Portuguese Republic) and those where the winner was elected in a second runoff round (as happened in the French Fifth Republic and the Romanian and Ukrainian elections). Importantly, this distinction is not between different institutions but between different elections with similar institutions.

We expect that the destabilizing effect of presidential elections will be concentrated in those cases where a second round between the two leading candidates is held. The run-off ballot essentially resembles the first and only round under plurality systems in that it will be decisive. The window for popular presidential elections to affect party system closure should open if none of the conventional coalitions succeeds, tempting candidates to vie for the best unconventional coalition.

One clear example of disturbed ideological and historical divisions is Poland in 2005. That year, Poles elected – almost concurrently – a new president and a new legislature. Facing competition from the post-communist Democratic Left Alliance (SLD), the two main post-Solidarity parties, Civic Platform (PO) and PiS, implicitly agreed before the elections that they would form a coalition government. The situation changed when Cimoszewicz, SLD's presidential candidate, withdrew due to a corruption scandal just before the parliamentary elections, which PiS won, beating PO by a close margin, with the populist agrarian Self-Defence (SRP) in third place. Fourteen days later, Tusk (PO's candidate) won the first round of the presidential elections by a similar margin. Both Tusk and Lech Kaczyński, PiS’ candidate and the runner-up, received a letter from Lepper, SRP's candidate, promising each of them his support in exchange for his participation in a future cabinet. In the second presidential debate before the runoff round, Tusk categorically refused Lepper's offer, but Kaczyński did not. The latter became president of Poland, and his twin brother Jarosław arranged a coalition government with the SRP and the League of Polish Families. The result was a blow to the competition structure that had characterized Polish politics since 1989, with fierce opposition between post-communist and post-Solidarity parties and the permanent exclusion of populist or ‘anti-establishment’ forces (Casal Bértoa and Guerra Reference Casal Bértoa, Guerra, Wolinetz and Zaslove2018).

While the Polish example stands out in dramaturgy, it is not unusual. Other instances where the composition of the government was affected by the patterns of party collaboration in immediately preceding presidential elections include Croatia (2000), Serbia (2004), Ukraine (2004), Bulgaria (2005), Slovenia (2008), Poland (2015), and France (2017).

Less destabilizing effects will occur in majoritarian elections where one of the presidential candidates has already succeeded in the first round. Initially, this is because minor parties, betting on an eventual second round, will not coordinate as much, presenting their candidacies separately. Thereupon, the abrupt end of the contest will deprive minor – in many occasions ‘anti-establishment’ – parties of their opportunity to ‘blackmail’ the winner, who becomes president by way of their own strength. If the presidential arena produces a winner by ‘conventional’ means, we thus expect less experimentation with ‘unconventional’ solutions in the executive arena. For all these reasons, we expect that:

To summarize our hypotheses, the popular election of a president will decrease party system closure (relative to constitutional monarchies and parliamentary republics), particularly under powerful presidencies and when electoral systems provide incentives for creative coalition building.

‘Direct’ and ‘Indirect’ Effects

Table 1 shows the estimated direct effects on party system closure. As can be seen in M1, our first hypothesis receives support from the data. Popular presidential elections have a significant negative coefficient, with party system closure estimated at 4.58 points lower in countries where citizens elect their president.

Table 1. Estimated effects of popular presidential elections

FGLS coefficients with standard errors in parentheses.

N (elections) = 735. Panels (unbalanced, heteroskedastic) = 64.

Six single-observation panels are uninformative.

**Significant at 99 per cent; *significant at 95 per cent; +significant at 90 per cent.

Importantly, this estimate is controlled for electoral fragmentation and party institutionalization. These two variables show the effects expected from the literature. Fragmentation reduces party system closure by 1.07 points for each ‘effective’ electoral party, while institutionalization increases closure by 0.32 points for each 10 per cent increase in average party age.Footnote ¹¹ Among the control variables, age of democracy and economic growth promote closure as expected; other controls do not have significant direct effects.

Based on the evidence, we can thus conclude that popular presidential elections directly impair party system stabilization at the executive level, controlling for the effects of the electoral/legislative levels. Moreover, as shown in Appendix 7, the effect occurs under different electoral systems.

Moving on to the effects of popular presidential elections on electoral fragmentation and party institutionalization, our analysis supports relevant expectations from the literature: fragmentation is increased by an estimated 0.35 ‘effective’ parties (M2), and party institutionalization is reduced by about 17 per cent (M3)Footnote ¹².

Popular presidential elections then affect party politics at the executive and electoral/legislative levels. In turn, the electoral/legislative levels affect the executive level in their own right. As was visualized in Fig. 1, presidential elections thus have a direct effect on party system closure and two indirect effects, which are mediated by electoral fragmentation and party institutionalization. Figure 2 reproduces Fig. 1, filling it with the respective coefficients from M1, M2, and M3.

Figure 2. Empirical path model of party system closure.

On this basis, the total effect of presidential elections on party system closure can be calculated as the sum of three quantities: the coefficient of the direct effect, the product of the two coefficients of the fragmentation path, and the product of the two coefficients of the institutionalization path (Baron and Kenny Reference Baron and Kenny1986). The multiplication ensures that the coefficients of the three paths are on the same scale. In particular, popular presidential elections increase electoral fragmentation by 0.35, and a one-point change in fragmentation decreases closure by 1.07. Thus, the change in fragmentation induced by presidential elections decreases closure by 0.35 × 1.07 = 0.37 points (95 per cent CI = [−0.72, −0.06]).Footnote ¹³ For party institutionalization, the effect of popular presidential elections (−0.18) and the effect on party system closure (3.31) yield an overall path of −0.18 × 3.31 = 0.60 points (95 per cent CI = [−0.97, −0.30]). The total effect of popular presidential elections on party system closure is thus estimated as follows:

$${\rm Total}\;{\rm effect} = {-}4.58 + ( {0.35 \times{-}1.07} ) + ( {-0.18 \times 3.31} ) = {-}5.55$$

with 95 per cent CI = [−7.56, −3.62]. To appreciate the size of this effect, let us evaluate it relative to the variability of the dependent variable: popular presidential elections decrease party system closure by 39 per cent of its general standard deviation (14.3) and by 45 per cent on the polity level (12.4). Expressed in terms of a related phenomenon, the effect on closure implies that the odds of parties entering the cabinet for the first time increase by about 40 per cent. For a single institution, these differences appear quite considerable.

Notably, the direct effect of presidential elections (−4.58) accounts for most of the total effect. The executive level (the main focus of our analysis) not only adds to the indirect effects of the electoral/legislative levels discussed in the literature but also dominates the larger model of party system closure.

The same impression also arises from the demanding assumptions of mediation analysis. While the direct effect merely requires control for exposure-outcome confounding, the indirect effects require three additional assumptions: control for mediator-outcome confounding and exposure-mediator confounding, and that no mediator-outcome confounder is itself affected by the exposure (VanderWeele Reference VanderWeele2015). While our models contain a comprehensive set of controls, this larger set of assumptions is apparently more vulnerable to violations.

One strategy to eliminate omitted controls is to include fixed effects for polity and decade in the regressions. This accounts for institutional, regional, and historical patterns that may confound our estimation strategy. Results in Appendix 6 show that there is reason to be cautious about the dual mediation model. While this test strengthens the direct effect, the indirect effects are weakened (particularly institutionalization). Thus, our study's main contribution, both theoretical and empirical, is the impact of direct presidential interference with executive politics.

Scrutinizing the Direct Effect

Turning to the scope conditions of the direct effect, we first need to recognize that not all presidencies are alike. Some are more powerful than others, which should affect whether parties in parliament will feel urged to consider presidential preferences when forming the executive. Thus, as expected by our second hypothesis, the election of an executive president should have stronger negative effects on closure than the election of a figurehead president.

Second, the use of majority rule for popular presidential elections provides an interesting opportunity to test the plausibility of our theory. If competition for broad presidential majorities indeed spills over into party politics, then the negative effect of presidential elections on party system closure should be stronger in those elections where a second round was held. This is the expectation of our third hypothesis.

In M4 of Table 2, we begin by adding presidential power as a predictor along with the presidential election. As can be seen, this variable, too, has a negative effect on party system closure, but the coefficient is insignificant and clearly weaker than that of popular presidential elections, which remains significant.

Table 2. Refined models of party system closure

Notes: see Table 1.

^a Cases in the base category, parliamentary systems, do not have natural values for the vote share of the leading candidate. The mean value of the observed cases was used for comparison.

However, a proper test of H2 requires an interaction of presidential elections with presidential power. M5 shows that the addition of a multiplicative term indeed produces the expected result. While the negative effect of the popular election of a figurehead president is a mere 0.70 points, the election of an executive president reduces closure by an additional 5.35 points, meaning 6.05 points overall. Thus, the estimate of M1 (−4.58) really was a mix of a strong effect for executive presidents and a much weaker (and insignificant) effect for figureheads. As expected in H2, the negative impact of popular elections is concentrated on those presidents whose power commands respect for their preferences in party politics.

The interaction in M5 can also be interpreted with a focus on the effect of presidential power itself. As indicated by the small and insignificant coefficient of that variable (0.33), power does not affect party system closure if the head of state is not elected by the people. Only in interaction with popular election does power reduce closure, with the aforementioned difference of 5.35 points between a figurehead and an executive president. The impact of presidential power is thus fully contingent on popular election, which supports the argument that it is the competition for presidential majorities that impedes party system stabilization, not a strong presidency per se.

M6 tests H3 by breaking down popular presidential elections into three types: single-round majority, two-round majority, and plurality/STV. As expected, we find that the effect is concentrated on plurality systems and majority elections that went into a second round (−3.63 and −5.74), while the coefficient for majority elections that were decided in the first round is small and insignificant (−0.74). This finding should lend considerable plausibility to our theory because the difference does not just reflect the number of election rounds. The effect occurs in majority elections with two rounds and in plurality elections, which, by definition, have only one round. The two types have in common the knowledge that all relevant actors knew the next round would be the last, bringing coalition-building incentives to the fore. Confirmation of H3 thus illustrates the mechanism through which party system closure is impaired by presidential influence on government formation.

M7, our last model, seeks to dispel possible doubts that the effect for majority systems may be related to reasons why a second round had to be held in the first place rather than to the second round itself. In this case, the true underlying variable would be the performance of the leading candidate: the stronger the first-round winner, the more structured the party alliances are at this time, and the less likely a second round. However, controlling for this variable shows that the alternative explanation carries little weight. The difference between second- and first-round elections remains large and significant. Thus, the institutional explanation prevails over a mere contextual one. Moreover, the coefficient of the vote share of the first-round leader is negative, suggesting that a strong first-round performance does not indicate structured party alliances; rather, it indicates that a less structured system is easily swayed by a strong candidate.

Finally, we explored the interaction of our two scope conditions. Appendix 8 shows that the more powerful the presidency and the more distinct the incentives for coalition-building in the presidential arena, the stronger the negative effect on party system closure.