Electoral Studies 69 (2021) 102261
Available online 11 December 2020
0261-3794/© 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Survival of the fittest. Comparing entry and exit among niche and
mainstream parties in advanced democracies, 1945–2011☆
Marc van de Wardt a,b,*
, Joost Berkhout c
, Floris Vermeulen c
a
School of Business and Economics, Ethics, Governance and Society, Vrije Universiteit, Amsterdam, Netherlands
b
Research Group GASPAR, Ghent University, Le Centre d’´etude de la vie politique (CEVIPOL), Universit´e Libre de Bruxelels, Belgium
c
Department of Political Science, University of Amsterdam, Netherlands
A R T I C L E I N F O
Keywords:
New parties
Party survival
Party system change
Niche parties
Mainstream parties
A B S T R A C T
The turnover of political parties is a key mechanism of renewal of electoral choices. We present an organizational
ecological theory on party system change, predicting that party system saturation (i.e., the effective number of
parties compared to the party system’s carrying capacity) differently affects the entry and exit of niche and
mainstream parties from lower house elections. Pooled times-series analyses on 352 elections, 509 parties, and
21 established democracies demonstrate that party system saturation indeed increases the likelihood of exit of
mainstream parties but not of niche parties. Strikingly, we also find that party system saturation increases the
entry of mainstream parties. Hence, an important paradox arises since oversaturation negatively affects their
survival chances.
1. Introduction
National party systems differ considerably in the frequency with
which new parties enter and existing parties exit. Some of today’s
advanced democracies have provided fertile breeding ground for parties
such as En Marche in France, Podemos and Ciudadanos in Spain, and
Movimento 5 Stelle in Italy. Yet, exit is also widespread. Consider how
Italy’s Democrazia Cristiana fell apart, or the total disappearance of the
Dutch Lijst Pim Fortuyn and Ireland’s Progressive Democrats. As noted by
Hooghe and Marks (2018, 112) ‘the source of dynamism in party systems
is new political parties’ rather than the transformation of established
parties. Hence, this study explores what determines why parties enter
the electoral contest (in this study: a lower house election) in the first
place and what energizes them to continue doing it in the future.
Extant research has mostly examined entry and exit separately. The
party entry literature has provided important insights into how structural
and institutional features of a polity affect new party entry (e.g.,
Hug 2001; Tavits 2006). Recently, this literature has also began to
consider more dynamic elements like voter discontent (Sikk 2012; Tavits
2006), party-voter incongruence (Laver and Schilperoord 2007), party
collapse (Laroze 2019), voter turnout (Lago and Martínez 2011) and the
effective number of parties (Kselman et al. 2016). Nonetheless, how
short-term electoral market dynamics affect entry has remained underexplored.
Similarly, studies on party exit have shown how party characteristics
like party origin, organization and ideological novelty affect
party survival (e.g., Bolleyer and Bytzek 2013; Bolleyer et al. 2019). Less
is known, however, about how the space (or lack thereof) on the electoral
market affects party exit.
Our article fills these voids by offering a twofold contribution. First,
we build on organizational ecology, an important tradition in organizational
sciences, to explain the entry and exit of political parties (also
see Lowery et al., 2013). We rely on an encompassing measure of party
system saturation (PSS) recently introduced by Van de Wardt and Van
Witteloostuijn (2019). PSS captures the difference between the effective
number of electoral parties (ENEP) present and the number predicted
based on the party systems’ carrying capacity. The latter is set by variables
such as cleavages, electoral openness and the heterogeneity of the
political supply. Based on the case of the Netherlands, Lowery et al.
(2013) have found that parties were more likely to exit and less likely to
enter in response to increasing PSS. To test these arguments on a much
☆
This research was supported by postdoctoral research grants from the Research Foundation Flanders ‘FWO’ (Grant number: FWO16/PDO/198) and the Fund for
Scientific Research (F.R.S.-FNRS) (Grant number: 28091302). We would like to thank Tarik Abou-Chadi, Marcel Hanegraaff, Bonnie Meguid, Simon Otjes, Gijs
Schumacher, the participants in the ECPR 2015 Joint Sessions Workshop ’Conceptualising and Comparing Interest Groups and Interest Group Systems’, the three
anonymous reviewers and the editor for their useful comments.
* Corresponding author. De Boelelaan 1105, 1081 HV, Amsterdam, Netherlands.
E-mail addresses: m.p.vande.wardt@vu.nl (M. van de Wardt), d.j.berkhout@uva.nl (J. Berkhout), f.f.vermeulen@uva.nl (F. Vermeulen).
Contents lists available at ScienceDirect
Electoral Studies
journal homepage: http://www.elsevier.com/locate/electstud
https://doi.org/10.1016/j.electstud.2020.102261
Received 27 January 2020; Received in revised form 10 November 2020; Accepted 17 November 2020
Electoral Studies 69 (2021) 102261
2
larger scale, we rely on a cross-national measure of PSS (see Van de
Wardt and Van Witteloostuijn, 2019).
Second, contrary to Lowery et al. (2013), we propose that the effect
of PSS on entry and exit differs between niche and mainstream parties.
We argue that niche parties carve out a niche for themselves, either by
emphasizing non-economic issues thereby avoiding the dominant
dimension of contestation (e.g., Meguid 2005; Wagner 2012), and/or by
taking an extreme position on the general left-right dimension (e.g.,
Adams et al., 2006). Mainstream parties, in turn, mainly emphasize
economic issues and adopt centrist positions. Consequently, they are
poorly differentiated from their competitors. Hence, PSS should particularly
foster the exit of mainstream parties and deter them from
entering.
Our analysis based on 509 parties from 21 established democracies
that participated in 352 post-war elections reveal that mainstream
parties are indeed likelier to exit when PSS increases. Strikingly, their
entry rates increase rather than decrease with PSS. As expected niche
party entry and exit is not systematically related with PSS.
In advance, it is useful to clarify, first, that party entry and exit each
requires a distinct modelling strategy, which is why the research design
is split up in two studies. We follow the state-of-the-art on party entry
and exit – two different literatures – by studying entry with the aggregate
count of new parties per election (e.g., Hug, 2001; Tavits, 2006) and
party exit at the level of party-election combinations (e.g., Lowery et al.,
2013).1
Yet, since PSS varies at the level of elections, it can explain both
the count of new parties per election and whether individual parties will
survive until the next election. Secondly, we consider a broad and a
narrow definition of entry and exit. Our broad definition includes any
party as new in its first electoral contest except for a party name change;
thus, parties started without the help of members of existing partiers,
splinters, mergers as well as divisions are new here. Our narrow definition,
in turn, considers mergers and divisions as "old" rather than new
parties. We do the same in our exit analyses: the broad definition codes
each last electoral contest except for a name change as exit, while the
narrow definition considers mergers and divisions as survival rather
than exit.
2. A new perspective on party entry and exit
Organizational ecology studies how competition for scarce resources
(e.g., members, customers, funding) determines entry and exit of organizations
such as social movements (e.g., Vermeulen 2013) interest
groups (Gray and Lowery 1996), and public organizations (Van Witteloostuijn
et al. 2018). Organizational ecology’s basic assumption is that
organizations in any organizational population rely on the same key
resources to exist (Hannan and Freeman 1977). The model posits that
when this population’s density grows, resources become scarcer and the
population’s carrying capacity is reached. Subsequently, existing organizations
will be driven out of business, new organizations will be deterred
from entering, or both. Organizational ecology admits that
adaptation to competitive pressures may help organizations to survive,
but argues that deep and successful adaptation is rare, because organizations
resist core changes, and if they ultimately change, they are often
too late (Hannan and Freeman 1984). Hence, resource competition
among parties is expected to increase party exit (and their replacement
by new parties) rather than adaptation by existing parties.
Several studies have begun to apply organizational ecology to the
entry, exit and adaptation of parties. Van de Wardt et al. (2017) focus on
the effect of niche density on party entry and exit, finding that a higher
number of competitors in a party system’s niche increases exit within
that niche, while not deterring entry in that niche. Lowery et al. (2013)
compare the ENEP with the carrying capacity of the Dutch party system.
They find that if ENEP surpasses carrying capacity, which we define as
an oversaturated party system, parties will be more likely to exit and less
likely to enter. In a recent study, based on a cross-national and longitudinal
measure of party system saturation (PSS), Van de Wardt and Van
Witteloostuijn (2019) find no evidence that parties engage in core
changes (i.e., to increase the nicheness of their platform or to merge)
when PSS increases. This confirms organizational ecology’s background
assumption of limited adaptation. This study relies on the same measure
of PSS, enabling us to test the predictions of Lowery et al. (2013) beyond
the Dutch case. Contrary to Lowery et al. (2013), we also propose that
PSS strikes back differently on niche and mainstream parties.
PSS is the difference between the ENEP present and the carrying
capacity of a party system. In organizational ecology, carrying capacity
is defined as the maximum number of organizations that can be sustained
in a given environment. In case of parties, the carrying capacity
equals the predicted ENEP based on a country’s electoral rules (Cox
1997), cleavages (Lipset and Rokkan 1967), the political agenda’s issue
diversity (Lowery et al., 2013) and the interactions between these variables
(Clark and Golder 2006). Hence, cleavages (public demand for
parties), the diversity of the political agenda (political supply), and the
openness of a country’s electoral institutions determine the available
room for parties in the system. A party system is oversaturated when
more effective parties contest elections than predicted by these
variables.
How does PSS relate to other concepts of a party’s competitive
environment? A first body of literature focusses on the role of political
opportunity structure (POS) to explain the electoral breakthrough of
specific party families like green (Kitschelt 1988; Kitschelt, 1994) and
radical right (Kitschelt and McGann 1997; Rydgren 2004). Within the
POS approach, the crucial independent variable is whether there in an
ideological niche for a specific ideology. Next, general political opportunities
like the openness of the electoral system and the ideological
convergence of mainstream parties are considered (e.g., Rydgren 2004).
These models are relatively good in explaining the successful entry or
electoral success of specific parties or party families under particular
circumstances. Yet, since a fundamental part of the model relies on
ideology-specific opportunities, it cannot simultaneously be applied to
different party families. The latter is the main strength of our indicator
of PSS. Below we work with a parsimonious model to measure the carrying
capacity for political parties in general that travels across party
families, party systems of consolidated democracies and time. Consequently,
our model of PSS is relatively high on Sartori’s (1970) ladder of
abstraction. As he noted, this is appropriate for concepts that are
designed to travel across regions (in our case: across consolidated democracies),
and thus for the purpose of this paper.
Second, it is relevant to stress that PSS differs from extra-system
volatility (the amount of vote shifts from established to new parties):
an indicator which has recently been proposed as indicative of the
permeability of the electoral market (Mainwaring et al. 2017, 2). While
extra-system volatility infers permeability from the success of newcomers,
PSS focusses on the available space in the party system. Hence,
contrary to the extra-system volatility indicator, PSS is also a potential
cause of the electoral success of newcomers rather than only its result. In
fact, an election with high extra system volatility likely increases PSS
and could subsequently increase the competitiveness and limit the
permeability of the party system for future newcomers.
Finally, it is important to note that Laroze (2019) argues that party
collapse in the previous elections could serve as a measure of the size of
the policy space that could be exploited by new parties. She also shows
empirically that the successful entry of new parties is directly related to
the exit of parties in the previous elections. Hence, this relationship
between party collapse and successful party entry plays lip service to our
assumption that party systems have finite carrying capacities. Yet, only
taking the degree of party collapse as an indicator of open space neglects
that simultaneously the carrying capacity for parties may be expanding
1
Hence, our entry and exit models have different controls. Nevertheless, in
section 2.7 of the SI we show that the results also hold if we include the same
country-level controls in both models.
M. van de Wardt et al.
Electoral Studies 69 (2021) 102261
3
or contracting.
In sum, the measure of PSS first introduced by Van de Wardt and Van
Witteloostuijn (2019) offers a novel approach to measure the competitiveness
of party systems.
3. Differences between niche and mainstream parties
Below we formulate our hypotheses regarding party entry and exit,
which happens when a party contests lower house elections for the first
or last time. While party entry is always a voluntary decision, we assume
that party exit can be both voluntary and involuntary. Our expectations
differ from Lowery et al. (2013) on one crucial aspect, namely that we
expect PSS to strike back differently on niche and mainstream parties.
Importantly, several competing approaches exist. First, scholars differ as
to whether nicheness is to be determined based on the issues parties
emphasize or based on their positional extremity. The saliency approach
argues that niche parties reject the traditional class-based orientation of
politics and that they focus on a limited set of issues. Mainstream parties
do the exact opposite and stick to economic issues (Bischof 2017;
Meguid 2008; Wagner 2012). In turn, Adams and co-authors (2006)
popularized a spatial conception, defining niche parties as those with
extreme positons on the general left-right position, while arguing that
mainstream parties occupy the political centre. Throughout we assume
that parties can either be distinctive because they mobilize
non-economic issues, because of their extreme left-right platform, or
because of both. Specifically, communist, ecologist, ethnic, Protestant,
radical right, regionalist, special issue and the non-Scandinavian
agrarian parties are defined as niche. Christian democrat, conservative,
liberal, social democrat and Scandinavian agrarian parties as
mainstream.2
Consequently, we differ from the saliency approach, as
based on Adams et al. (2006) we code communist/radical left parties as
niche because they have an extreme left-right position, while the
saliency-approach either discards these parties (e.g., Meguid 2008) or
codes them as mainstream (e.g., Bischof 2017). In turn, we differ from
Adams et al. (2006) and follow the saliency approach by including
regionalist, ethnic and special issue parties as niche based on their
emphasis of non-economic issues.3
Second, there is controversy about whether niche and mainstream
parties are to be operationalized based on their party family as above (e.
g., Adams et al., 2006; Meguid 2008; Spoon and Klüver 2019) or by
means of concrete characteristics that can vary by elections (Bischof
2017; Bischof and Wagner 2017; Meyer and Wagner 2013). As explained
by Mair and Mudde (1998), the party family approach would be useful if
one wishes to focus on the ideological imprint of parties, thus, on what
they are rather than what they do. Political parties are identified as
ideological vessels consisting of a whole package of characteristics that
together constitute a party’s identity. This way of examining parties
contrasts with the “policy approach” that focuses on what parties do in
one specific election by examining time-variant characteristics like the
nicheness or extremity of a party’s profile in isolation (e.g., Bischof
2017; Wagner 2012). Besides ideological characteristics, scholars have
also proposed to directly measure other alleged characteristics of niche
parties like the degree to which they are policy-seeking and dominated
by their activists (Bischof and Wagner 2017).4
We will adopt elements of both approaches. Our main emphasis will
lie on party family, as we do not wish to fully detach ideologically differentiation
from the genetic imprint of parties. As argued by Downs
(1957, 142), ideologies cannot be thrown off as if they were disguises.
Even if a mainstream party would enter a niche segment, it has been
shown that parties cannot “steal” associative issue ownership (the
spontaneous association by voters between issues and parties) from
other parties (Tresch et al. 2015). Hence, party family better gauges that
niche parties enjoy a first mover advantage on the niche segments of the
electoral market (also see De Vries and Hobolt 2020, 54). While we
certainly do not suggest that what parties do in one election has no
consequences for how they are differentiated, we assume that a party’s
ideological imprint carries more weight than its platform in one election.
Focusing on party family also enables us to consider that niche parties
differ from mainstream parties on multiple dimensions (e.g., ideological
differentiation, issue ownership, party goals). Hence, it is the whole
package that must be considered.
That said, we believe that focusing on party attributes like nicheness
also has numerous advantages. First, rather than treating the niche/
mainstream category like an empirical commonality (Wagner 2012),
this approach directly taps into the alleged differences between niche
and mainstream parties. Hence, we will also directly study the impact of
concrete traits ascribed to niche parties (also see Bischof and Wagner
2017). Another strength is that the nicheness approach treats nicheness
as a relative concept (Meyer and Miller 2015, 262). Therefore, both our
nicheness and positional extremity measure below capture the distinctiveness
of the focal party’s platform vis-a-vis the other parties in the
system.
4. Party exit hypothesis
For our theoretical argument, it mainly matters that niche parties are
better positioned to avoid competition with other parties on the same
issues for the same voters than mainstream parties. This is because of
their ideological differentiation (either through salience or positions).
Mainstream parties, however, tend to focus on economic issues and to
moderate their position towards the centre to maximize their vote and
office ambitions (Adams et al., 2006; De Vries and Hobolt 2020, 51).
While such a catch-all strategy could maximize their votes in the short
run, the main drawback is that mainstream parties become poorly
differentiated from their competitors, which will also make it more
difficult for them to differentiate and effectively target their supporters
(Ezrow et al., 2010). Another drawback is that the centrist voters targeted
by mainstream parties display less solid associations with political
parties, meaning that they can easily lose their voters in the future
(Karreth et al., 2013). Hence, despite that mainstream parties are
generally more of a constant in party systems than niche parties, a share
of their electorate may still be weak partisan identifiers. Moreover, the
catchall strategies of mainstream parties could alienate their less centrist
core supporters (Karreth et al., 2013) who potentially provide them with
an enduring source of support and other resources like time and money
(Schofield and Sened, 2005).
For niche parties we expect the opposite characteristics to apply. As
2
Extant research does not distinguish between Christian-democrat and
Protestant parties. Yet, since the latter tend to mobilize more conservative
positions on morality issues, we believe that they are clearly differentiated from
Christian democratic parties. Further we distinguish Scandinavian agrarian
parties from other agrarian parties, as the first are often regarded as mainstream
parties. They hold centrist positons and have been in government coalitions.
3
While both Adams et al. (2006) and saliency based work code green parties
as niche, in our view, they better fit the saliency-based definition as scholars
have argued that they have relatively moderate positons (e.g., Dalton 2009),
which would make them mainstream in a spatial sense. It is, however, uncontestable
that they mobilized around non-economic issues.
4
A third controversy is whether due to the rise of new issue dimensions, some
niche parties have become mainstream. However, Wagner (2012, 850–51)
shows that in most countries economic issues remain the primary focus of
electoral debates. Notwithstanding that since the 1980s the salience of the
liberal-authoritarian dimensions has increased, policy niches have increased at
the same time. That is, mainstream parties have certainly increased attention
for these issues and shifted to the right, but the radical right has done the same
(Wagner and Meyer 2017). Hence, we believe that there is insufficient ground
to make claims that from a certain moment onward niche parties like the
radical right become mainstream.
M. van de Wardt et al.
Electoral Studies 69 (2021) 102261
4
said, they are clearly differentiated ideologically. Moreover, several
studies have argued that these parties are policy-seeking and mostly
responsive to their core voters (Adams et al., 2006, Ezrow et al., 2010,
Przeworski, 1986; Klüver and Spoon, 2016; but see Tromborg, 2015).5
For niche parties this would be an effective vote-seeking strategy
because their supporters are supposed to be more policy-oriented than
the voters of mainstream partiers (D’Alimonte, 1999; Kitschelt 1997).
Because of their horizontal party organization, the leaders of niche
parties also have less leeway to respond to environmental incentives
(Adams et al., 2006; Ezrow et al., 2010). Hence, according to these
authors, niche parties are confined to stay within their niche and do not
respond to public opinion, even though this sets a natural ceiling in
terms of votes (Adams et al., 2006).
Based on the aforementioned studies, we contend that especially
mainstream parties will become vulnerable in an oversaturated party
system. They are less distinguishable from competitors and owing to
their preference of votes over policy and the power of the party leadership
over their activists, they have less of a loyal base to rely on. Lastly,
mainstream parties may be more inclined to voluntarily exit an overcrowded
electoral market, as electoral success is their primary motivation.
We, therefore, propose that PSS will only increase the exit of
mainstream parties, while niche parties’ chances of exit are not systematically
related to PSS.
Party Exit Hypothesis (H1). Party system saturation only increases
the likelihood of exit of mainstream parties.
As said above, we will also examine whether the concrete characteristics
(ideological nicheness, positional extremity, being office
seeking and being dominated by the party activists) commonly ascribed
to niche parties indeed mitigate the effect of higher PSS (also see Bischof
and Wagner 2017; Schumacher et al. 2013).
5. Party entry hypothesis
While we can clearly derive from the organizational ecological
literature that oversaturated systems revert to their carrying capacity
through increased exit rates, it is less clear-cut whether oversaturation
also suppresses entry. The traditional model posits that when the population
reaches its carrying capacity, resources become scarce, and organizations
will be deterred from entering (Hannan and Freeman 1977).
Yet, other studies suggest that higher density can, for instance, create
better opportunities for learning organizational skills or may ease the
cost of collective action – both of which lead to higher rates of entry
(Aldrich 1999). Furthermore, another view citing Colinvaux, a biologist
(Gray and Lowery 1996, 3), suggests that prospective entrants might
simply be incapable of strategically acting upon the carrying capacity:
‘the way an animal breeds has very little to do with how many of it there
are … The numbers that may live are set by the environment, and these
are quite independent of how fast a species makes babies’. Hence, if this
is true, a higher number of organizations will foster organizational death
but not lower entry rates.
The party entry literature, however, appears to largely agree that
new parties are able to strategically respond to their environment. The
theory of strategic entry assumes instrumentally rational elites who
must maximize their vote share in the short-run to enjoy the spoils of
office and/or to influence policy (Cox 1997; Tavits 2006, 102). Assumed
is that new parties will only enter the electoral contest if the benefit of
holding political office multiplied by the probability of getting elected is
equal to or higher than the cost of entry.
In keeping with the assumption of new parties that optimally strategize
in response to their environment, we expect that PSS will influence
mainstream party elites’ entry propensity. Mainstream parties are less
well distinguished from their competitors. Hence, they should be
discouraged from entering oversaturated party systems where ideological
differentiation is important. Analogous to their exit, we expect no
systematic relationship between PSS and niche party entry.
Party Entry Hypothesis (H2). Party system saturation only decreases
the entry of mainstream parties.
Contrary to H1, we will not evaluate H2 based on the concrete
characteristics of parties, as new parties are hardly included in extant
databases in their first electoral contest.
6. Measuring party system saturation
We compiled a longitudinal dataset containing information between
1945 and 2011 for 21 established Western democracies (see Fig. 1). To
measure PSS we use the residuals from a model that regresses the ENEP
on a party system’s characteristics. We rely on the model of ENEP
published in Van de Wardt (2017, Model 2, p. 50). The ENEP, or the
carrying capacity of the party system, is determined by societal heterogeneity
(measured on the basis of the cleavage that is seen as most
consequential within a country) (Clark and Golder 2006), the diversity
of the political supply side in terms of the dimensionality (Stoll 2011)
and fractionalization (Lowery et al., 2013; Zons 2015) of the party
system agenda. Hence, these time-variants factors capture changes in
the nature of party competition such as increased dimensionality. Each
of these explanations is interacted with the permissiveness of the electoral
system to capture the intuition that the latter may act as a brake or
catalyst (Clark and Golder 2006). The measure is based on 387 elections
that took place in 25 advanced democracies between 1945 and 2011
(which is why our sample stops in 2011). This model explains 31% of the
variance. Van de Wardt (2017) shows that the explanatory power of the
model drops and determinants of ENEP fail to have their hypothesized
effect when the newer democracies of Central and Eastern Europe are
added to the analysis. Therefor we focus on consolidated democracies
only. Of the 25 consolidated democracies for which we have PSS data,
we could only include the 21 that are also in the ParlGov database from
which we derive entry and exit data. For further detail, we refer to Van
de Wardt’s (2017), Van de Wardt and Van Witteloostuijn (2019) and the
SI (Section 3.1).
Fig. 1 maps the observed and predicted ENEP for each country. The
distance between the two lines depicts the degree of under or oversaturation.
If the grey line is above the black line, the system is oversaturated;
if the black line is above the grey line, the system is
undersaturated; and if the two lines overlap, the system is saturated. For
instance, the high oversaturation of the Italian party system in 1994 can
be understood from the fact that it simultaneously adopted more
disproportional electoral rules (as denoted by the black line, the carrying
capacity contracts) and witnessed increasing electoral fragmentation (as
shown by the grey line) in the aftermath of the Mani Pulite corruption
scandal which caused the demise of the Christian Democrats and the
entry of new parties. In turn, the heavy undersaturation of New Zealand’s
party system from the early nineties onward is driven by the 1993
electoral reform from First Past the Post to Mixed Member Proportional
system, which substantially widened the carrying capacity. Yet, as
shown the observed ENEP has only moderately increased, suggesting
that new and existing parties have not profited very much from this
opportunity. The Spanish case provides an example of a party system
that has been continuously undersaturated throughout the time span of
our analyses. This is no surprise, given that until the 2015 elections, the
party system was dominated by only two parties: the Partido Popular and
the PSOE. However, more recently and beyond the time frame of our
analysis, parties like Podemos, Ciudadanos and Vox have exploited this
open space. These examples illustrate the face validity of the PSS
measure.
5
Tromborg (2015) finds evidence that niche parties moderate their platform
when a proximate moderate coalition forms. This suggests that under specific
circumstances, niche parties could also respond to electoral incentives.
M. van de Wardt et al.
Electoral Studies 69 (2021) 102261
5
Fig. 1. Predicted versus observed ENEP in most recent elections. Notes: the distance between the two lines depicts the degree of under or oversaturation.
Fig. 2. Regression coefficients H1 from Table A5 of the SI (90% ci). For continuous variables the coefficients denote the effect of a one standard deviation increase.
Broad definition: N = 2961. Narrow definition: N = 2890.
M. van de Wardt et al.
Electoral Studies 69 (2021) 102261
6
7. Empirical strategy for the Party Exit Hypothesis (H1)
We are interested in how parties adapt to their environment (in this
case: PSS) regardless of how successful they are in doing so. Hence, we
define entry and exit as (non)-participation in the electoral contest,
meaning that a party could enter and exit without ever having gained
parliamentary representation. For exit and entry data, we rely on ParlGov
(D¨oring and Manow 2015). Parties obtaining at least 1% of the vote
or one seat in lower house elections are systematically included in this
extensive dataset. Thus, given our aims, we needed to ensure that all
party-election observations are included: if party X runs in elections t
and t+1 but only in election t manages to acquire at least 1% of the votes
or a seat, Parlgov will exclude party X in election t+1, while we will
include it at t and t+1.6
The first dependent variable, Party exit, is dichotomous (0 alive, 1
exit) and measured at the level of party/elections. A party receives a
score of 1 if it does not contest any other lower house elections after t.
We employ two operationalizations of exit. The first is unrestrictive and
follows Lowery et al. (2013): only party name changes are excluded as
instances of exit. This means that parent parties exit, even if the party
merges, or divides into multiple new parties. This operationalization is
consistent with organization ecological theory in the espoused belief
that when a party merges or falls apart, it is likely not competitive in its
current form. Our second operationalization is narrower and excludes
mergers and divisions.
We created a binary indicator denoting niche or mainstream status
based on the ParlGov data on party family. Specifically, we coded nonScandinavian
agrarian parties, communist, ecologist, ethnic, Protestant,
radical right regionalist and special issue parties as niche and Christian
democrat, conservative, liberal, social democrat and Scandinavian
agrarian parties as mainstream.
Besides party family, we also focus on concrete party characteristics.
Our time-variant nicheness indicator is based on parties’ issue emphases
in their election manifestos derived from the Comparative Manifestos
Project (CMP) (Volkens et al., 2013). We aggregated all issues into
Stoll’s (2011) seven policy dimensions: economic, cultural-ethnic, religious,
post-materialist, foreign policy, democratic-authoritarian, or
urban-rural. Following Meyer and Wagner (2013), we calculated how
many standard deviations a party’s emphasis of a dimension was above
the weighted average emphasis of the other parties in the same election.
Issue emphases were weighted according to parties’ vote shares. Then
we subtracted the party’s standard deviation on the economic dimension
from its largest positive standard deviation on any of the non-economic
niche dimensions.7
As for the other characteristics, to measure the extremity
of a party’s general left-right position, we calculated the absolute
distance in standard deviations of a party’s so-called rile score to the
mean of the other parties in the system. And the extent to which the
party leadership prefers policy over office and that activists dominate
the party leadership was derived from an expert survey by Laver and
Hunt (1992).
Finally, we controlled for party-level explanations of exit, i.e., the
number of consecutive elections that they were not represented in
parliament/government (Bolleyer 2013) and the rootedness (Bolleyer
and Bytzek 2013) and origin (genuinely new, merger, splinter, division,
successor) of their organization (e.g., Beyens et al. 2016). Data on
Fig. 3. Marginal effect of PSS for niche and mainstream parties (left) and marginal effect of being a niche party for increasing levels of PSS (right) based on broad
definition (90% ci). For regression coefficient see Table A6 (Model 2) of SI.
6
That we still exclude parties that never obtained 1% of the votes or one seat
poses no threat to the validity of our conclusions. A large share of these parties
could run for other objectives than electoral success like political satire or
entertainment. As such, they offer an unsuitable testing ground for the
hypotheses.
7
A positive score on this continuum implies that a party’s relative emphasis
of the niche segment it emphasizes the most is above its emphasis of the
economy; a negative score denotes the reverse; finally, a score of zero suggests
equal emphasis.
M. van de Wardt et al.
Electoral Studies 69 (2021) 102261
7
electoral/government participation and party origin from Parlgov
(D¨oring and Manow 2015). Descriptive statistics are provided in
Table A3 of the SI.
Party exit was examined by means of discrete time duration models
(Rabe-Hesketh and Skrondal 2008). The data structure is such that a
party contributed one party/election observation for each election it was
included in our dataset. Thus, a party received a score of 1 on the
dependent variable, Party exit, if it will not reappear in any other
election after t (0 if reappears). We capture the hazard rate of exit by
transforming the number of elections contested until t into n-1 dummy
variables. In so doing, we control for the fact that older parties are more
institutionalized, helping them to survive (Panebianco 1988). Since
elections are clustered within countries and parties, we specified standard
errors clustered at both levels.8
8. Evaluating the Party Exit Hypothesis (H1)
Table A1-A10 of the SI present the case selection, model specifications,
descriptive statistics and regression tables for each analysis in this
paper. Fig. 2 visualizes the results. The time dummies are omitted from
the table, but Figure A1 of the SI presents the hazard rate of exit,
showing that the hazard decreases the more elections a party has contested.
As shown in Fig. 2, we find that PSS increases exit both under the
broad (log odds = 0.202, p < .05) and narrow definition (log odds =
0.143, p < .1). However, as denoted by the significant interaction
PSS*Niche party, the effect differs between niche and mainstream
parties. Due to the presence of the interaction term, the “main effect” of
saturation can be interpreted as the effect for mainstream parties (Niche
party = 0). If PSS increased with one standard deviation, the logged odds
of mainstream party exit increase by 0.388 (p < .01, Broad definition),
or a factor of 1.474, which is a sizable effect. In turn, the significant
interaction between PSS and niche party (b = − 0.389, p < .01, Broad
definition) shows, that for niche parties, the effect is about zero (0.388-
0.389). Notably, the same pattern emerges under our narrow definition
of exit. This provides strong support for H1.
In Fig. 3 we present the marginal effects. As shown in the figure on
the left, PSS increases the exit of mainstream parties, but has no effect on
niche party survival. The right hand figure presents the marginal effect
of being a niche party (compared to being a mainstream party) on the
likelihood of exit for increasing values of PSS (x-axis). Should the confidence
intervals entrap the zero line, niche and mainstream parties have
the same chance of exit; and in cases of positive (negative) values, niche
parties are more (less) likely to exit. As shown, when a party system is
under saturated with − 2.8 effective parties or less, niche parties have
significantly higher odds of exit than mainstream parties. This higher
baseline propensity of exit could, for instance, be due to the fact that
niche parties are often younger organizations, which increases organizational
failure (Freeman et al. 1983). Also we know that if niche parties
join coalitions, pressures to moderate will become intense, which combined
with their inexperience will likely foster electoral defeat (e.g.,
Bale and Dunphy 2011) followed by exit. In turn, when the system is
oversaturated with 0.1 effective parties or more, this pattern reverses,
and mainstream parties become confronted with higher exit chances.
Fig. 4. Marginal effect of PSS on exit (y-axis) for increasing values of nicheness (upper-left), left-right extremity (upper-right), activist dominance (bottom-left) and
policy-seekingness (bottom-right) based on broad definition (90% ci). The b coefficients for the interaction terms are − 0.049 (p < .01), − 0.130 (p > .1), − 0.048 (p <
.01) and − 0.130 (p < .05). For regression coefficient see Table A8 (Model 1–4) of SI.
8
Due to our modest number of higher level cases we opt for robust-clustered
standard errors rather than multilevel models to deal with higher level clustering
at the country level (Hox and McNeish 2020, 218).
M. van de Wardt et al.
Electoral Studies 69 (2021) 102261
8
When the system is oversaturated with, say, 4 effective parties, niche
parties’ probability of exit becomes 0.145 times lower than mainstream
parties (see Fig. 3).
Fig. 4 shows that except for positional extremity, all traits commonly
associated with niche parties – i.e., their programmatic nicheness,
dominance of their supporters and preference of policy over office
(Bischof and Wagner 2017) – all mitigate the effect of PSS. For parties
with a nicheness score below 0, PSS significantly increases exit; when
nicheness ranges between 0 and 12, PSS exerts no effect; and when
nicheness is above 12, PSS actually reduces the likelihood of exit.
Further we see that activist dominance reduces exit. That is, as soon as
activist dominance is above 8 (at the midpoint of 10 they are as dominant
as the party leadership), PSS no longer increases exit. Finally, we
find that if parties are very policy seeking, the effect of PSS on exit
dwindles. Hence, except for positional extremity, all characteristics
commonly ascribed to niche parties matter. We, however, stress that the
non-findings on positional extremity do not suggest that radical left
parties are not protected against PSS. In Figure A11 of the SI we show
that like the other niche party families, their exit rates are left unaffected
by higher PSS. This nicely illustrates the added value of comparing the
impact of ideological imprint (based on party family) with what a party
does in one particular election.
All controls are in the expected direction. Most importantly, rooted
organizations were less likely to exit (e.g., Bolleyer and Bytzek 2013)
and those longer excluded from parliamentary representation and office
are more likely to do so (Bolleyer 2013).
9. Empirical strategy for the Party Entry Hypothesis (H2)
We constructed three dependent variables: the number of new
parties, new niche parties, and new mainstream parties at election t.
Contrary to party exit, we cannot study entry at the party/election-level.
This would require comparing all parties that exist as organizations
where some decide to contest elections and others not to. However, it is
virtually impossible to gather reliable data on all parties existing as
organizations. Since we focus on aggregate entry rates, we cannot
interact PSS with the type of party as in H1. Hence, here we test H2 by
evaluating the effect of PSS on the aggregate entry of mainstream and
niche parties in two separate models (Hence, throughout the N is the
same). Also contrary to our analysis of party exit, we only evaluate party
entry based on party family due to the simple fact that the time variant
characteristic used above are unavailable for most new parties. We
translated our broad and narrow definition of exit (see above) to our
entry analyses. Our narrow definition is in line with the literature on
strategic entry that only considers parties started without the help of
members of existing parties or splinters as new parties (Hug 2001; Tavits
2006).
Keeping with the theory of strategic entry (Tavits 2006), we
controlled for variables tapping into the costs (i.e., registration costs,
logged petitions, public party financing) and benefits of entry (corporatism)
and a party’s likelihood of success (i.e., duration of democracy,
changes in unemployment rate and GDP and the logged size of the
population). Data derived from Tavits (2006). Descriptive statistics are
displayed in Table A4 of the SI.
Since the dependent variables are over-dispersed count variables, we
opted for a negative binominal regression (Hall et al. 1984), clustering
elections within countries.
10. Evaluating the Party Entry Hypothesis (H2)
In Fig. 5 we again begin with the effect of PSS on all parties. Strikingly,
contrary to Lowery et al. (2013), we find that PSS at t-1 produces
higher rather than lower entry rates at t, but only under our broad entry
definition (log of expected counts = .179, p < .1).
In Fig. 6 we disaggregate entry rates by niche (top) and mainstream
Fig. 5. Regression coefficients H2 from Table A9 of the SI (90% ci). For continuous variables the coefficients denote the effect of a one standard deviation increase. N
= 184.
M. van de Wardt et al.
Electoral Studies 69 (2021) 102261
9
parties (bottom), we again find differences. Niche party entry rates do
not systematically respond to PSS.9
For mainstream parties’ we find,
contrary to H2, that their entry rates significantly increase rather than
decrease when PSS was higher in the previous elections (logs of expected
counts = .527 against broad definition and 0.484 against narrow definition,
p < .05). If PSS increases with one standard deviation, the entry
of mainstream parties would increase with a factor of 1.69. This appears
a sizable effect. However, Fig. 7 displays the predicted number of newly
entering parties (upper-left), niche parties (upper-right) and mainstream
parties (bottom-left) along the observed values of PSS based on the
broad definition. As indicated by the increasing slope of the line in
Fig. 7, the effect of PSS on mainstream party entry is clearly nonlinear. It
is problematic that the steeper slope at very high levels of PSS lacks
common support in the data (Hainmueller et al. 2019), as shown by the
white-barred histogram in the background of Fig. 7. If we were to increase
PSS along its interquartile range (from − 0.73 to 0.71), the
number of new mainstream parties would only increase with 0.19 new
parties. Even though this effect is statistically significant (p < .01), it is
more modest than suggested by the overall coefficient. That being said,
it remains at odds with H2.10
Why is that so? One plausible explanation consistent with our findings
on exit (H1) could be that higher PSS at t-1 increases the exit of
mainstream parties between t-1 and t, which in turn creates space for
new mainstream parties at t. Moreover, as discussed below in the
example of the UDF, if a party exits, different types of successors may
rise from its ashes, which would increase entry rates in the next
elections. This is most obvious in case of merges: the predecessors that
exit at t will produce a new party at t+1. Additionally, also activists or
politicians of disbanded parties can launch new parties. To test whether
the effect of PSS t-1 is indeed mediated by the exit of mainstream parties
after t-1, Model 2 controls for the exit of mainstream and niche parties
after the previous elections. While these exit rates exert no effect on the
entry of niche parties, we find that higher exit rates of mainstream
parties do increase their entry rates at t. While the effect of PSS shrinks,
it remains statistically significant, suggesting that the effect of PSS on
mainstream party entry is partly mediated through its effect on exit.
It is unsurprising that the effect of mainstream party exit is larger
under the broad definition. This definition also includes mergers and
divisions as instance of entry and exit. These types of exit will by definition
increase entry rates in the next elections. Hence, perhaps it is
more interesting to look at our narrow definition that discards such
transformations as cases of entry and exit. Recall that it only considers
parties formed without the help of existing parties or splinters as new
parties. Again we find that the effect of PSS is mediated by the exit of
mainstream parties at t-1. So, mainstream parties that get weeded out in
an oversaturated electoral marked will be replaced by new mainstream
parties. Against this narrow definition, we also find that mainstream
party entry increases in response to niche party exit. Yet, since we have
already shown above that there is no relationship between PSS and niche
party exit, this is not a mediated effect as above.11
As for the controls, most variables pertaining to the costs and benefits
of entry are insignificant. Along with the null findings on H2, this casts
new light on the assumption that within consolidated democracies new
parties smoothly act upon costs and benefits of entry and factors
enhancing their likelihood of success (Tavits 2006). Caution is, however,
required. Like Tavits (2006) our narrow definition of new parties includes
both genuinely new and splinter parties; yet, Zons (2015) has
Fig. 6. Regression coefficients H2 from Table A9 of the SI (90% ci). For continuous variables the coefficients denote the effect of a one standard deviation increase. N
= 184.
9
As shown In Figure A12 of the SI, this is because the effects for individual
niche party families are either insignificant or in different directions. We refrain
from going in detail here as H2 only expresses expectations about the empirical
pattern for mainstream parties.
10
As discussed in Section 2.4. of the SI, we also find that PSS increases the
entry of communist parties. A likely explanation is that after the fall of the
Berlin Wall, many of these parties disbanded, while producing radical left
offspring parties (March and Mudde, 2005).
11
Also at the aggregate level we find that PSS t-1 only increases mainstream
party exit.
M. van de Wardt et al.
Electoral Studies 69 (2021) 102261
10
shown that both subtypes differently respond to the incentives in the
model. Nonetheless, that mainstream parties’ entry rates do not
decrease with PSS and even slightly increase (while they have poorer
survival chances in oversaturated systems), suggests that a large subset
of parties does not optimally respond to its environment.
11. Sensitivity analyses
Several analyses, detailed in the SI (Section 2), were carried out to
assert the robustness of our findings. They involved: (1) estimating PSS
based on the residuals from Clark and Golder’s (2006) study on the
ENEP, (2) rerunning the model on different operationalizations of niche
and mainstream parties, (3) testing whether the findings hold if we
disaggregate the niche party concept into its constituent party families,
(4) asserting that the findings are not biased by specific sub dimensions
driving PSS, (5) asserting that the results are not biased by potential
influential cases in our estimation of PSS, (6) showing that PSS continues
to exert an effect if one controls for the carrying capacity around a
party’s position, and (7) examining H1 with more country-level
controls.
12. Conclusion and discussion
Parties are crucial actors in a democracy. It is therefore important to
develop an understanding of what determines their entry and exit. Our
analyses on 21 established democracies between 1945 and 2011
demonstrate that party system saturation (PSS) increases the exit of
mainstream parties. Strikingly, we found no evidence that mainstream
parties’ entry rates respond accordingly: they are more rather than less
likely to enter oversaturated party systems also if we exclude mergers
and divisions as instances of entry and exit.
Our new, organizational ecological perspective on party entry and
exit helps explain why mainstream parties, such as Belgium’s Vivant,
France’s Union Pour La D´emocratie Française (UDF), and Denmark’s
Centrum-Demokraterne disappeared from the political scene. In the
elections preceding their exit, we find that the ENEP exceeded carrying
capacity. Subsequently, each of these parties was confronted with
electoral defeat, after which they disbanded. In its last 2002 elections,
the UDF, for instance, was confronted with many rivalling mainstream
parties (e.g., UMP, Parti Socialiste), some even splinters from itself
(D´emocratie Lib´erale and Rassemblement pour la France), making it difficult
to set themselves apart ideologically. After its electoral defeat, the
party split in two: one fraction supported by UDF’s member base started
a social liberal party, MoDem, while the other wing founded Nouveau
Centre. The UDF itself ceased to exist in 2007. The fact that two new
mainstream parties, MoDem and Nouveau Centre, rose from its ashes,
despite the oversaturation of the French party system, may appear
counterintuitive, but is fully consistent with our finding that oversaturation
does not deter but even slightly increases mainstream party
entry.
By applying organizational ecological theory to party entry and exit,
this study provides several important innovations. First, the party
competition literature commonly assumes that entry and exit occurs
independently from the presence of competitors. PSS offers an empirical
approach to add the relative crowdedness of the electoral market more
explicitly to the equation. Second, by showing how PSS interacts with
party characteristics, we managed to fruitfully bridge the party
competition literature and organizational ecology. Rather than
assuming that environmental pressures similarly affect parties, as
Lowery et al. (2013) do, we have shown that PSS differently affects the
Fig. 7. Predicted counts of new parties (upper-left), new niche parties (upper-right) and mainstream parties (bottom-left) based on broad definition (90% ci). For
regression coefficients see Table A10 (Model 1, 2 and 4) of SI.
M. van de Wardt et al.
Electoral Studies 69 (2021) 102261
11
entry and exit of niche and mainstream parties. Third, organizational
ecology recommends studying organizational entry and exiting simultaneously,
as populations of organizations could be moving back to their
carrying capacity because of increased exit, inhibited entry, or both. We
found that mainstream parties are more likely to exit in response to PSS;
yet, PSS also increases their entry.
Even though the effect on entry is only modest, we have explained
this seeming paradox with the notion that by increasing the exit of
mainstream parties, PSS will also increase the entry of mainstream
parties in the next elections. As illustrated in the UDF example, mainstream
parties driven out of business can still produce offspring through
the activities of its activists or former politicians. Also they can be
replaced by genuinely new mainstream parties expecting to benefit from
the space they left behind. A prominent example of this type of
replacement includes Italy’s Democrazia Cristiana (DC). After its dismal
showing in the 1992 elections the party was disbanded. This was not
only because of the Mani Pulite corruption scandal, but also because of
increased electoral competition due to, for instance, the rise of Lega
Nord. In fact, our data shows that in 1992 the Italian party system was
oversaturated with 2.2 effective parties. Consistent with our findings for
H2, this encouraged new mainstream parties to enter the next 1994
elections. While the Partito Populare Italiano (their formal successor) and
Centro Christiano Democratico (a splinter) can be seen as DC’s own
offspring, also a prominent, genuinely new party, Forza Italia, emerged
on the scene. This even increased the oversaturation of the system to
four effective parties. That an overcrowded market does not discourage
but even slightly encourages mainstream party entry suggests that this
type of parties does not optimally respond to its environment. As argued,
mainstream parties are less well distinguished from their competitors,
meaning that they would benefit from entering undersaturated party
systems. While merging (producing exit and entry) could still be seen as
rational adaptation to an oversaturated electoral market (Van de Wardt
and Van Witteloostuijn, 2019), PSS also increases the narrow type of
entry (i.e., splinters and genuinely new ones).
Why do mainstream parties depict this suboptimal behaviour? A first
explanation could be that career politicians are more likely to self-select
into mainstream than niche parties (also see Panebianco 1988; Schumacher
et al. 2013, 466). As compared to ‘believers’ whose participation
primarily depends on the party’s platform, ‘careerists’ are more driven
by material and status-oriented incentives. Arguably, careerists will be
more inclined than believers to start new parties instead of exiting
politics if their party is driven out of business, even in an oversaturated
party system. In this way, exited mainstream parties thus leave behind
the seeds for new mainstream party entries. A second account that could
also explain why genuinely new mainstream parties are more likely to
enter oversaturated electoral markets could be that whether to pursue
one’s goals by forming a political party is a complex decision involving
information shortage. Party founders must assess their potential electoral
viability together with the costs and benefits of entry. While information
on the cost of ballot access is readily available, assessing ones
potential electoral viability involves considerable uncertainty. According
to bounded rationality theory, in case of uncertainty, human beings
will rely on proxies (Bendor et al., 2011). One such proxy could be
electoral fragmentation where high electoral fragmentation would
encourage the entry of new parties because it signals that the electoral
market is well permeable (Mainwaring et al. 2017). Hence, when
considering the launch of a new mainstream party, elites could infer
from the oversaturation of the party system that they can be electorally
viable in that voters are volatile and willing to consider a broad range of
options. Consequently, higher PSS will increase mainstream party entry
rather than decrease it as we originally expected.
While these two explanations could potentially explain the paradox,
we stress again that the effect on entry is only weak and that future
research in this area is needed. Another challenge for future research
would be to develop an approach that would enable to measure the
saturation in specific locations in the party system. Yet, measuring the
carrying capacity for different party families will be a difficult task, both
theoretically and methodologically, as fine-grained explanations and
data would be required. This paper has provided an important first step
by showing how the carrying capacity of the party system as a whole
affects the entry and survival of niche and mainstream parties.
Data availability
Data will be made available on request.
Appendix A. Supplementary data
Supplementary data to this article can be found online at https://doi.
org/10.1016/j.electstud.2020.102261.
References
Adams, James, Clark, Michael, Lawrence, Ezrow, Glasgow, Garrett, 2006. ‘Are niche
parties fundamentally different from mainstream parties? The causes and the
electoral consequences of Western European parties’ policy shifts, 1976–1998’. Am.
J. Polit. Sci. 50 (3), 513–529.
Aldrich, Howard, 1999. Organizations Evolving. Sage, Thousands Oaks.
Bale, Tim, Dunphy, Richard, 2011. In from the cold? Left parties and government
involvement since 1989. Comp. Eur. Polit. 9 (3), 269–291.
Bendor, Jonathan, Diermeier, Daniel, Siegel, David A., Ting, Michael M., 2011.
A Behavioral Theory of Elections. Princeton University Press, New Jersey.
Beyens, Stefanie, Paul, Lucardie, Deschouwer, Kris, 2016. The life and death of new
political parties in the low countries. W. Eur. Polit. 39 (2), 257–277.
Bischof, Daniel, 2017. Towards a renewal of the niche party concept: parties, market
shares and condensed offers. Party Polit. 23 (3), 220–235.
Bischof, Daniel, Wagner, Markus, 2017. What makes parties adapt to voter preferences?
The role of party organization, goals and ideology. Br. J. Polit. Sci. 50 (1), 1–11.
Bolleyer, Nicole, 2013. New Parties in Old Party Systems: Persistence and Decline in
Seventeen Democracies. Oxford University Press.
Bolleyer, Nicole, Bytzek, Evelyn, 2013. Origins of party formation and new party success
in advanced democracies. Eur. J. Polit. Res. 52 (6), 773–796.
Bolleyer, Nicole, Ibenskas, Raimondas, Bischoff, Carina, 2019. Perspectives on political
party death: theorizing and testing downsian and sociological rationales. Eur. Polit.
Sci. Rev. 11 (1), 19–35.
Clark, William Roberts, Golder, Matt, 2006. ‘Rehabilitating duverger’s theory: testing the
mechanical and strategic modifying effects of electoral laws’. Comp. Polit. Stud. 39
(6), 679–708.
Cox, Gary W., 1997. Making Votes Count: Strategic Coordination in the World’s Electoral
Systems. Cambridge University Press.
D’Alimonte, Roberto, 1999. Party Behavior in a Polarized System: The Italian Communist
Party and the Historic Compromise. In: Müller, Wolfgang C. (Ed.), Policy, Office or
Votes? How Political Parties in Western Europe Make Hard Decisions and Kaare
Strøm. Cambridge University Press, Cambridge, pp. 141–171.
Dalton, Russell J., 2009. Economics, environmentalism and party Alignments: a note on
partisan change in advanced industrial democracies. Eur. J. Polit. Res. 48 (2),
161–175.
De Vries, Catherine E., Hobolt, Sara B., 2020. Political Entrepreneurs: the Rise of
Challenger Parties in Europe. Princeton University Press.
D¨oring, Holger, Manow, Philip, 2015. Parliaments and Governments Database (ParlGov):
Information on Parties, Elections and Cabinets in Modern Democracies.
Development Version. www.parlgov.org.
Downs, Anthony, 1957. An economic theory of political action in a democracy. J. Polit.
Econ. 65 (2), 135–150.
Ezrow, Lawrence, De Vries, Catherine E., Steenbergen, Marco R., Edwards, Erica E.,
2010. Mean voter representation and partisan constituency representation: do
parties respond to the mean voter position or to their supporters? Party Polit. 17 (3),
275–301.
Freeman, John, Carroll, Glenn R., Hannan, Michael T., 1983. The liability of newness:
age dependence in organizational death rates. Am. Socio. Rev. 48 (5), 692–710.
Gray, Virginia, Lowery, David, 1996. The Population Ecology of Interest Representation
Lobbying Communities in the American States. University of Michigan Press, Ann
Arbor.
Hainmueller, Jens, Mummolo, Jonathan, Xu, Yiqing, 2019. How much should we trust
estimates from multiplicative interaction models? Simple tools to improve empirical
practice. Polit. Anal. 27 (2), 163–192.
Hall, Bronwyn H., Griliches, Zvi, Hausman, Jerry A., 1984. Econometric models for count
data with an application to the patents-R & D relationship. Econometrica 52,
909–938.
Hannan, Michael T., Freeman, John, 1977. The population ecology of organizations. Am.
J. Sociol. 82 (5), 929–964.
Hannan, Michael T., Freeman, John, 1984. Structural inertia and organizational change.
Am. Socio. Rev. 49 (2), 149–164.
Hooghe, Liesbet, Marks, Gary, 2018. ‘Cleavage theory meets Europe’s crises: lipset,
rokkan, and the transnational cleavage’. J. Eur. Publ. Pol. 25 (1), 109–135.
M. van de Wardt et al.
Electoral Studies 69 (2021) 102261
12
Hox, Joop, McNeish, Daniel, 2020. Small samples in multilevel modeling. In: Small
Sample Size Solutions. A Guide for Applied Researchers and Practitioners.
Routledge, London, pp. 215–225.
Hug, Simon, 2001. Altering Party Systems: Strategic Behavior and the Emergence of New
Political Parties in Western Democracies. University of Michigan Press, Ann Arbor.
Karreth, Johannes, Polk, Jonathan T., Allen, Christopher S., 2013. Catchall or catch and
release? The electoral consequences of social democratic parties’ march to the
middle in Western Europe. Comparative Political Studies 467, 791–822.
Kitschelt, Herbert, 1988. Left-libertarian parties: explaining innovation in competitive
party systems. World Polit. 40, 194–234, 02.
Kitschelt, Herbert, 1994. The Transformation of European Social Democracy. Cambridge
University Press, Cambridge.
Kitschelt, Herbert, McGann, Anthony J., 1997. The Radical Right in Western Europe: A
Comparative Analysis. University of Michigan Press, Ann Arbor.
Klüver, Heike, Spoon, Jae-Jae, 2016. Who responds? Voters, parties and issue attention.
Br. J. Polit. Sci. 46 (3), 633–654.
Kselman, Daniel M., Powell, Eleanor Neff, Tucker, Joshua A., 2016. Crowded space,
fertile ground: party entry and the effective number of parties. Polit. Sci. Res.
Methods 4 (2), 317–342.
Lago, Ignacio, Martínez, Ferran, 2011. Why new parties? Party Polit. 17 (1), 3–20.
Laroze, Denise, 2019. Party collapse and new party entry. Party Polit. 25 (4), 559–568.
Laver, Michael, Hunt, W. Ben, 1992. Policy and Party Competition. Routledge, London.
Laver, Michael, Schilperoord, Michel, 2007. Spatial models of political competition with
endogenous political parties. Philos. Trans. R. Soc. Lond. B Biol. Sci. 362 (1485),
1711–1721.
Lipset, Seymour Martin, Stein, Rokkan, 1967. Party Systems and Voter Alignments:
Cross-National Perspectives. Free Press, New York.
Lowery, David, et al., 2013. Policy agendas and births and deaths of political parties.
Party Polit. 19 (3), 381–407.
Mainwaring, Scott, Gervasoni, Carlos, Espa˜na-Najera, Annabella, 2017. Extra-and
within-system electoral volatility. Party Polit. 23 (6), 623–635.
Mair, Peter, Mudde, Cas, 1998. The party family and its study. Annu. Rev. Polit. Sci. 1
(1), 211–229.
March, Luke, Mudde, Cas, 2005. ‘What’s left of the radical left? The European radical left
after 1989: decline and mutation’. Comp. Eur. Polit. 3 (1), 23–49.
Meguid, Bonnie M., 2005. Competition between unequals: the role of mainstream party
strategy in niche party success. Am. Polit. Sci. Rev. 99 (3), 347–359.
Meguid, Bonnie M., 2008. Party Competition between Unequals. Strategies and Electoral
Fortunes in Western Europe. Cambridge UP, Cambridge.
Meyer, Thomas M., Miller, Bernhard, 2015. The niche party concept and its
measurement. Party Polit. 21 (2), 259–271.
Meyer, Thomas M., Wagner, Markus, 2013. Mainstream or niche? Vote-seeking
incentives and the programmatic strategies of political parties. Comp. Polit. Stud. 46
(10), 1246–1272.
Panebianco, Angelo, 1988. Political Parties: Organization and Power. Cambridge
University Press.
Przeworski, Adam, 1986. Paper Stones: A History of Electoral Socialism. University of
Chicago Press, Chicago.
Rabe-Hesketh, Sophia, Skrondal, Anders, 2008. Multilevel and Longitudinal Modeling
Using Stata. Stata Press, Texas.
Rydgren, Jens, 2004. Explaining the emergence of radical right-wing populist parties: the
case of Denmark. W. Eur. Polit. 27 (3), 474–502.
Sartori, Giovanni, 1970. Concept misformation in comparative politics. Am. Polit. Sci.
Rev. 64 (4), 1033–1053.
Schofield, Norman, Sened, Itai, 2005. Modeling the interaction of parties, activists and
voters: Why is the political center so empty? European Journal of Political Research
443, 355–390.
Schumacher, Gijs, Catherine, E., de Vries, Vis, Barbara, 2013. Why do parties change
position? Party organization and environmental incentives. J. Polit. 75, 464–477, 02.
Sikk, Allan, 2012. Newness as a winning formula for new political parties. Party Polit. 18
(4), 465–486.
Spoon, Jae-Jae, Klüver, Heike, 2019. Party convergence and vote switching: explaining
mainstream party decline across Europe. Eur. J. Polit. Res. Advance online
publication.
Stoll, Heather, 2011. Dimensionality and the number of parties in legislative elections.
Party Polit. 17 (3), 405–429.
Tavits, Margit, 2006. Party system change: testing a model of new party entry. Party
Polit. 12 (1), 99–119.
Tresch, Anke, Jonas, Lefevere, Walgrave, Stefaan, 2015. ‘“Steal me if you Can!”The
impact of campaign messages on associative issue ownership’. Party Polit. 21 (2),
198–208.
Tromborg, Mathias Wessel, 2015. Space jam: are niche parties strategic or looney? Elect.
Stud. 40, 189–199.
Van de Wardt, Marc, 2017. Explaining the effective number of parties: beyond the
standard model. Elect. Stud. 45, 44–54.
Van de Wardt, Marc, Berkhout, Joost, Vermeulen, Floris, 2017. ‘Ecologies of ideologies:
explaining party entry and exit in west-European parliaments, 1945–2013’. Eur.
Union Polit. 18 (2), 239–259.
Van de Wardt, Marc, Van Witteloostuijn, Arjen, 2019. Adapt or perish? How parties
respond to party system saturation in 21 Western democracies, 1945-2011. Br. J.
Polit. Sci. 1–23. Advance online publication.
Van Witteloostuijn, Arjen, et al., 2018. Explaining the survival of public organizations:
applying density dependence theory to a population of US federal agencies. Publ.
Adm. 96 (4), 633–650.
Vermeulen, Floris, 2013. Mutualism, resource competition and opposing movements
among Turkish organizations in Amsterdam and Berlin, 1965-2000. Br. J. Sociol. 64
(3), 453–477.
Volkens, Andrea, et al., 2013. The Manifesto Data Collection. Manifesto Project (MRG/
CMP/MARPOR). Wissenschaftszentrum Berlin für Sozialforschung (WZB), Berlin.
Wagner, Markus, 2012. Defining and measuring niche parties. Party Polit. 18 (6),
845–864.
Wagner, Markus, Meyer, Thomas M., 2017. ‘The radical right as niche parties? The
ideological landscape of party systems in Western Europe, 1980–2014’. Polit. Stud.
65 (1), 84–107.
Zons, Gregor, 2015. The influence of programmatic diversity on the formation of new
political parties. Party Polit. 21 (6), 919–929.
M. van de Wardt et al.