An approximation problem in computing electoral volatility

The topic of electoral volatility was not at the center of academic work in Latin America until Scott Mainwaring and Timothy R. Scully’s seminal 1995 work Building Democratic Institutions: Party Systems in Latin America (cited in Electoral Volatility as an Expression of Party System Equilibrium). Preceding analyses primarily focused on explaining the breakdown of democratic politics in the region during the 1960s and 1970s. Conventional wisdom that departed from the classic work of Sartori in Parties and Party Systems (Cambridge, UK: Cambridge University Press, 1976), maintained that stable party systems are crucial for the durability of democracies, focusing his attention on aspects such as party system polarization and fragmentation. Mainwaring and Scully shift the discussion, arguing that previous literature on the region neglected and inadequately conceptualized an equally important property of party systems: their level of their institutionalization. According to Mainwaring and Scully, party system institutionalization (PSI) is formed by four different dimensions. The first is stability in the patterns of party competition. Thus, institutionalized party systems are those in which actors develop expectations, orientations, and behavior based on the premise that practices and organizations will prevail into the foreseeable future. Mainwaring’s 2018 work, Party Systems in Latin America (cited in Electoral Volatility as an Expression of Party System Equilibrium), argues that this is the only relevant dimension in PSI, while considering that the other three are just underpinnings that facilitate it. So according to this work, an institutionalized party system is the one in which a stable set of parties interacts regularly in stable ways. This stability of interparty competition is traditionally measured with the Pedersen volatility index, a comprehensive measure of the net systematic shift in levels of electoral support for parties across elections. As volatility is negatively correlated with this important dimension of party system institutionalization, conventional wisdom holds that political representation deteriorates when there is persistent high volatility. To this debate, the well-cited 2006 article by Mainwaring and Torcal, “Party System Institutionalization and Party System Theory after the Third Wave of Democratization” (cited in Electoral Volatility as an Expression of Party System Equilibrium), adds the idea that this lack of stability in the patterns of competition in party systems, measured by electoral volatility, is a typical characteristic of new and developing democracies. According to that study, the most important defining characteristic of party systems in less developed countries is captured by their lack of institutionalization, in other words, the amount of electoral volatility in their party systems. Since the publication of these three contributions, the debate on party system dynamics in the region has focused on cross-national levels of electoral volatility, their relationship with other indicators of party system stability, and their consequences for democratic quality and performance, while also broadening the analysis to Europe.

This is the third of three chapters on political party systems and structures of competition, and presents an overall review. In the first section, Approaches to the Classification of Party Systems: A Review it looks at the principal existing approaches to the classification of party systems, pointing to both their limits and possibilities when applied within comparative analysis. It then goes on in the second section, Party Systems and the Competition for Government, to underline the importance of understanding the structure of competition in any given party system, since in many ways the whole notion of a party system is centred on the assumption that there exists a stable structure of competition. Structures of competition can be seen to be either closed (and predictable) or open (and unpredictable), depending on the patterns of alternation in government, the degree of innovation or persistence in processes of government formation, and the range of parties gaining access to government. The emphasis in the third section, Party Systems and Electoral Outcomes, is on the need to distinguish between processes of electoral change on the one hand, and changes in party systems and the structures of competition on the other, a distinction which also allows the possibility of situations in which electoral change is the consequence rather than the cause of party system change.

Party systems represent parts of political systems which arise as a result of interactions between political parties. Party relations produce characteristics which place a particular party system within the typology of party systems. A number of factors can be considered in explaining the nature of party competition, most often placed within the categories of institutional and sociostructural factors. This paper analyses the impact of full and partial social cleavages on party systems. Given that the theory of social cleavages has proved insufficient in explaining party differences and the dynamics of party systems, especially in new democracies, we will improve the analysis by including the concept of partial social cleavages. This research shows the unequivocal influence of dominant social cleavages on the situation and changes in party systems. Although in some cases no changes in the type of party system have occurred, it can be concluded that exactly in those cases there exist permanent and ingrained social cleavages, but also partial cleavages which affect the relations in the party system at the given time. Identity issues stand out as the dominant topic in political competition, especially in the countries where ethnic relations have not been resolved.

This article sets out to examine the extent of party system change in Scandinavia since the ‘earthquake elections’ in the early 1970s witnessed the parliamentary breakthrough of new parties and, in particular, the rise of a populist radical right. It deploys an analytical framework derived from Berglund and Lindström's five‐party Scandinavian model and an identification of the ‘core structures’ of the frozen party system in the region. In assessing party system change the significance of changes in the patterns of interaction between parties at the elite level, that is in the governmental and parliamentary arenas, is emphasised over and above electoral change. It is argued that the core features of the Scandinavian party systems have changed much less since 1970 than the structure of party competition and that the single most important development in the party politics of the region has been that the historic non‐socialist groupings have acquired increased ‘relevance’ as coalition parties both severally and collectively. The article concludes by asking: ‘so what?’ Can an indication of the extent of party system change be of assistance in understanding the wider workings of the political system and the operation of the legislative process?

Although democratic regimes in Latin America since the early 1980s have been surprisingly durable, party systems in much of the region continue to experience very high levels of electoral instability. A critical juncture approach to institutional change suggests that variation in party system stability is related to the impact of market liberalization in the 1980s and 1990s on the programmatic alignment—or dealignment—of partisan competition. Market reforms that were adopted by conservative leaders and opposed by a major leftist rival aligned party systems programmatically, allowing societal opposition to be channeled into institutionalized forms of competition that were highly stable in the postadjustment era. By contrast, bait-and-switch reforms adopted by populist or leftist leaders were programmatically dealigning for party systems, leaving them vulnerable to highly destabilizing reactive sequences in the aftermath to the reform process—including mass social protests, the demise of historic conservative parties, and the outflanking of traditional populist or leftist parties by more radical, anti-neoliberal outsiders. The political dynamics of market-based economic adjustment thus heavily conditioned the ways in which party systems would process the postadjustment revival of populist and leftist alternatives in the region.

The Japanese political system of 1946-1996 has often been defined by the continuous rule for four decades of the conservative Liberal Democratic party (LDP), which had held a majority of seats in the Diet between its formation in 1955 until it lost its majority in the Upper House (House of Councilors) in 1989. Under the Japanese political milieus, the LDP has been in a position of semi-permanent governance since 1955 except for a few years in the mid-1990s. The first questionable issue, here, is how the LDP had maintained its dominant position during that period and how one-party dominance system had sustained? How had electoral volatility affected the party system change? Can we expect a dramatic change in Japanese politics in near future? In relation to these questions, how can we apply the theories of comparative parties and party systems to 1946-1996 history of Japanese party politics.

This article is part of the special cluster titled Parties and Democratic Linkage in Post-Communist Europe, guest edited by Lori Thorlakson, and will be published in the August 2018 issue of EEPS This article introduces a special section on parties and democratic linkage in post-communist Europe. It sets out the main objectives and research questions that guide the four articles in this special section, presenting these in the context of the comparative politics literature on party and party system change and democratic development. It introduces the key arguments of the articles in the section, arguing that the contributions identify regionally distinctive patterns of party and party system behaviour in Central and Eastern Europe. These patterns have fuelled a quest for more suitable conceptual and measurement tools and call for diversity in comparative analysis, combining intra and inter regional comparison.

This article examines the development of the east German party system from the peaceful revolution in the former GDR to the aftermath of the 1994 federal election. It takes into account its format, polarisation, fragmentation, asymmetry, volatility, legitimacy, segmentation and government durability. The analysis shows that there was not only a complete transformation of the former GDR's party system between autumn 1989 and autumn 1990 but also a general change of the east German party system between 1990 and 1994. Both at the federal and at the Land level, the high volatility resulted in a considerably less fragmented system with a parliamentary format reduced to three parties: the CDU, SPD and PDS. The change in the electoral dimension also led to an increase in segmentation and to government instability at the Land level and coincided with a decrease of legitimacy. Reasons for the party system change are to be be found in developments at the macro‐level, that is, the institutional framework party compe...

Party systems, that is, the number and the size of all the parties within a country, can vary greatly across countries. I conduct a principal component analysis on a party seat share dataset of 17 advanced democracies from 1970 to 2013 to reduce the dimensionality of the data. I find that the most important dimensions that differentiate party systems are: “the size of the biggest two parties” and the level of “competition between the two biggest parties.” I use the results to compare the changes in electoral and legislative party systems. I also juxtapose the results to previous party system typologies and party system size measures. I find that typologies sort countries into categories based on variation along both dimensions. On the other hand, most of the current political science literature use measures (e.g., the effective number of parties) that are correlated with the first dimension. I suggest that instead of these, indices that measure the opposition structure and competition could be used to explore problems pertaining to the competitiveness of the party systems.

Since 2020, the world has been officially battling a COVID-19 pandemic. Even countries with established crisis management plans and years of experience in handling political and economic crises, have been shaken. In the midst of the pandemic’s rampant effects, how politicians handle the crisis is of crucial importance to the preservation, development, and protection of nations in the future. Who is in power determines not only the stability, but the political course of countries. Hence, what happens to the party system as a result of an exogenous shock is a question we need to answer. Importantly, we have little evidence on how the handling of the COVID-19 pandemic affected party competition. Building on the party systems literature, we examine the effect of the pandemic on electoral volatility, party system size, and the number of new party contestants. We hypothesise that, in countries where the incumbent government handles the crisis less effectively, electoral volatility tends to be higher, party system size tends to be larger, and more new parties tend to enter the electoral race. Drawing on evidence from national parliamentary elections held by electoral democracies from March 2020 to April 2022, the empirical results support our hypothesis.

This article considers party system effects and change in government-opposition dynamics in EU referendums. Relying on the analysis of party stances, party-voter alignments and campaign dynamics in 12 EU referendums in France, Ireland, Great-Britain and Spain, it shows that EU referendums tend to interfere with traditional party system dynamics in majoritarian democracies. By clearly manifesting a pro-European convergence between incumbent and mainstream opposition parties, they constitute a fertile ground to awake the ‘sleeping giant’ under certain conditions. EU referendums favor the temporary displacement of the partisan cleavage, create recurrent tensions for mainstream opposition parties and consistently reinforce the role played by protest parties. The recurrent intra-party factionalism or the limited mobilizations of pro-European opposition parties in referendum campaigns are thus not so linked with their ideologies or with endogenous factors, but are rather largely induced by their specific party system ‘situations’.

Cycles in Public Opinion and the Dynamics of Stable Party Systems

It can hardly be denied that the process of forming party system is long-term, complex and multidimensional one. The features of the “systemness”, e.g. stability, durability and predictability, may be achieved only after several years of democratic development. Thus, the analysis of the changes which take place in short period may give limited effects because of rapid changes of most frequently used quantitative parameters of the party system. From the other side, the comparison of the results of two or more consecutive parliamentary elections allows us to describe and to interpret some trends in political development. The aim of this article is to show the changes in the structure of political competition and in the number and size of the main parties, affecting the level of fractionalization and concentration of Polish party system between 2005 and 2007. By using traditional measures of stabilization of party systems on electoral, parliamentary and governmental arenas, I have tried to answer the question whether are there the symptoms of stabilization of Polish party system after 2005, or not. Comparing effective number of parties, the level of fractionalization and concentration, and the modes of forming the cabinet I have come to conclusion that, contrary to 2005 parliamentary election, there are some signs of party system stabilization in its two dimensions: representativeness and effectiveness. The structure of political scene seems to be more stable: no relevant party has appeared on it since 2001, the number of parties represented in the Sejm has diminished, the level of support for the strongest parties has increased and the electoral volatility has been lower in 2007 than in 2005. What is new after 2005 is that the structure of competition has changed. Two strong, conservative right-wing groupings have been main contenders and the post-communist Left is, for the time being, practically excluded from the struggle for power. The further stabilization of party system depends on capability to maintain this pattern of political competition.

The nationalisation of politics is a major political phenomenon deriving from the historical trend towards the formation of national electorates and party systems brought about by the progressive reduction in the significance of territorial cleavages. During the last 50 years, though the issue of vote nationalisation has been addressed by a large volume of literature, serious analysis of the Italian case has never made much progress, having been limited to the reflections of a few isolated authors. Over the past 20 years, a period marking the passage from the long period of polarised pluralism to the so-called ‘Second Republic’, the Italian party system has undergone profound changes, with the continuing emergence and growth of new political parties and a sharp increase in the levels of party fragmentation and volatility. How has nationalisation of the vote evolved in this changing framework? This article analyses the process of (de)-nationalisation of the vote in Italy and explains its evolution between the first (1948–1992) and the second (1994–2013) phases of the republican era, assessing the impact of various possible determinants. The empirical analysis shows that vote nationalisation in Italy is strongly associated with competition factors and with the level of institutionalisation of the party system.

ONE of the outstanding themes of party development in the United Kingdom since 1997 has been the effect on party politics of the Blair government’s programme of institutional reform. Carried through in the name of ‘modernisation’, the impact of this programme was primarily evident in two ways in 2000. The first was the consolidation of devolved party systems stemming from the reform of subcentral government; relatedly, the first direct election of a London mayor posed an unexpected challenge to party as such. The second element of institutional modernisation affecting party politics may prove even more significant in the long run: this was the introduction of a radically new regulatory framework across the UK. This article charts the detail of these developments by focusing, in turn, on party system dynamics in the UK and the new regulatory legislation.