New party parliamentary entry in Western Europe , 1960-2010

Although the number of studies of new political parties is gradually increasing, we still lack a comprehensive understanding of when new parties manage to enter national parliaments. The objective of this article is to explain the circumstances under which new parties enter national parliaments for the first time. Unlike earlier research, this study does not focus on individual party families. Instead, generally applicable explanations are sought. This is achieved through an examination of the importance of the political opportunity structure, that is, the external environment new parties face in their quest for parliamentary representation. Using data collected for 18 Western European countries for the period 1960-2010, the analysis shows that institutional factors are important to understand new party parliamentary entry. The sociological factors analysed in the study, however, do not seem to be of equal importance.


Introduction
Although the number of studies of new political parties is gradually increasing, we still lack a comprehensive understanding of when new parties manage to enter the most important political assembly, namely national parliaments.Since only very few new parties emerged during the first 70 years of the 20th century, scholars showed little interest in the area.According to the frozen party system theory of Lipset and Rokkan (1967), the 1960s' party systems reflected the cleavage structures of the 20th century, with the result that the party systems of the 1960s were virtually the same as those of the 1920s.During the last couple of decades, however, new parties have more frequently succeeded in entering national parliaments.Accordingly, scholarly interest has also risen.Due especially to the pioneer contributions of Hauss and Rayside (1978), Harmel and Robertson (1985) and the more recent studies by Hug (2001), Meguid (2008) and Hino (2012), a new party theory is slowly starting to emerge.Nevertheless, these studies, and most others as well, focus either on new party formation or on new party electoral success.Although a new party must attain some electoral success to enter parliament, parliamentary entry and electoral success are not synonymous.The objective of this article is to explain the circumstances under which new parties enter national parliaments for the first time.This is achieved through an examination of the importance of the political opportunity structure, that is, the external environment new parties face in their quest for parliamentary representation.
Since the entry of new parties into parliament is a subject related to research on both party formation and electoral success, I will make use of explanatory factors tested in prior studies of these specific issues.In short, two different explanatory perspectives are employed.Firstly, an institutional perspective postulates that a new party's prospects for successful parliamentary entry are influenced by how the political rules of the game are designed.Primarily, attention has been given to the electoral system and its impact on new parties.However, there are also other institutions of relevance.Rules on public party funding as well as regulations on parties' access to different forms of media potentially facilitate or hamper new party possibilities.Also, basic structures of the political system have been hypothesised as being significant.Hence, federalism and parliamentary government have been argued to be friendlier to newcomers than a unitary presidential political system (Harmel & Robertson, 1985;Hauss & Rayside, 1978;Hino, 2012;Willey, 1998).
Secondly, from a sociological perspective it is emphasised that political parties arise as a result of conflicts between different groups in society (Ware, 1996).However, as major societal changes such as industrialisation, urbanisation and economic growth have taken place, social group affiliation no longer necessarily determines voting patterns.The strict divisions into social groups were loosened when citizens' opinions and values changed.New dimensions of conflict brought new political issues.Since there is a time lag between voters and party movement, new niches open up for new political parties (Rydgren, 2003).From a sociological perspective, new party formation and ultimately entry to parliament are therefore a response to social change.This article will go on to survey theories about new parties in order to find out what explanatory factors should be tested in the analysis.In the first part of the empirical section the development of new party parliamentary entry, both temporally and spatially, will be mapped out.This will be conducted using data collected for 18 Western European countries for the period 1960-2010.In the second part of the empirical section the explanatory factors will be statistically tested using multivariate statistical methods.Finally, the conclusions are discussed and problematised.

How can new party parliamentary entry be explained?
Prior research on new parties is limited in at least two respects.Firstly, it focuses on explaining the formation or the varying degrees of electoral success of new parties.While party formation and party parliamentary entry are obviously separate events and thus potentially explained by different factors, new party parliamentary entry and new party electoral success are more adjacent concepts.However, while electoral success is an arbitrary concept to some extent, parliamentary entry is hard to misinterpret.Entry includes representation and consequently formal influence on decision-making.
Secondly, most of the literature focuses on specific party families, and consequently much attention has been given to radical right parties, green parties and regional parties.Treating new parties as one homogeneous group of parties has not been very common, although there are a number of important studies which, to different extents, have done just that (Harmel & Robertson, 1985;Hauss & Rayside, 1978;Hino, 2012;Hug, 2001;Meguid, 2008).This study aims to go beyond party-family-specific explanations for new party parliamentary entry.
Although previous explanatory studies on new parties have primarily dealt with formation and electoral success and not parliamentary entry, this study is guided by research from these adjacent areas of research.The results of these studies, so far, are rather mixed.While some argue that the institutional setting is of minor importance to understanding why new parties develop (Hauss & Rayside, 1978), others argue that is does.Hug (2001), for instance, finds that the costs of forming a party do matter.Still others have shown that different aspects of the electoral system are of importance in order to explain the electoral success of new parties (Hino, 2012).In regard to sociological explanations, Harmel and Robertson (1985) fail to find any significant effect of various social variables such as population size, religious and linguistic heterogeneity, income equality and levels of post-material sentiments within the population.Hino (2012), on the other hand, shows how different socio-economic factors do affect different types of new parties in different ways.
In essence, it is possible to identify two dominant theoretical perspectives from which new party research has been conducted: an institutional perspective and a sociological perspective.Together these two perspectives contribute to the understanding of what causes new parties to emerge and enter the parliamentary arena.Some use the concept political opportunity structure as an illustration of how hard or easy it is for outsiders to enter the political system.This concept originates from research into social movements and is a way to express the degree of 'openness' or 'accessibility' of a political system for political entrepreneurs (Arzheimer & Carter, 2006, p. 422).While some have a rather narrow definition of what should be included, others define it as a broader concept which includes a number of factors.Here the concept is used to collect both institutional factors and sociological factors under the same heading in order to illustrate the conditions under which new parties attempt to enter parliament.
The new party's chances of parliamentary entry are consequently dependent on a number of factors outside the party.In extreme cases, the political opportunity structure is very unfavourable.One obvious example of such a barrier is a high electoral threshold.Under other circumstances the political opportunity structure can be 'a perfect breeding ground' for new parties (Mudde, 2007, p. 202).Favourable possibilities for new parties arise when the institutional barriers are low, or when there is a widespread view that the established parties no longer represent the voters.A benign political opportunity structure can therefore be assumed to be a necessary condition for new parties to be elected to the national parliament.
A word of caution is needed here.Even though this article focuses on an analysis of the political opportunity structure, it is important to note that this factor alone does not determine whether a new party succeeds or fails.For a new party to succeed it needs to capitalise on a favourable political opportunity structure, an aspect that research has largely neglected so far.Just as new parties are not entirely free to determine their own fate (Lucardie, 2000, p. 180), friendly external conditions do not automatically translate into new party parliamentary entry.

Data and measures
In order to better understand the extent to which the political opportunity structure influences the chances of new parties, this study aims to explain the variations present in new party parliamentary entry in elections to the national parliament in 18 Western European countries between 1960 and 2010.The dependent variable, i.e. the number of new party parliamentary entries in an election, is defined as a first-time entry into the national parliament by a party that was not originally a member of the once-consolidated party system, defined here as the period prior to 1960 (cf.Mair, 1999, p. 210).Excluded from this population are merger parties insofar as at least one of the parties included was once a parliamentary party.The reason for this exclusion is that mergers differ in a significant way from split parties and genuinely new parties.While the latter are additional contestants in the electoral race, mergers can be seen as established parties that have simply been reorganised; in other words, old contestants in a new guise.Hence, the products of mergers arguably have an easier passage than the split parties and the genuinely new parties in getting elected for the first time.

Institutional factors
The institutional perspective highlights the rules of the political game.Primarily, various aspects of the electoral system have been emphasised as being of great importance.In studies of new party success, the electoral system is also a reoccurring predictor that is included in the analyses (e.g.Hino, 2012;Hug, 2001;Willey 1998).
As early as the 1950s, Duverger (1964) formulated what has since become known as Duverger's Law, in which he stated that 'the simple-majority single-ballot system favours the two-party system' and 'the simple-majority system with second ballot and proportional representation, favour multi-partism ' (pp. 217, 239).This would accordingly lead us to expect new parties to do better in countries with proportional electoral systems than in countries with majoritarian systems (Harmel & Robertson, 1985).However, since only two countries within the data set of this study, namely the UK and France, have majoritarian systems, a desirable level of variation would not be obtained if only a dichotomised variable had been used.Empirically, it has also been noted that it is not necessarily the case that proportional electoral systems are more favourable than majoritarian systems from the perspective of small parties (Taagepera, 2002).Since the total number of votes required for a seat in a country with single-member constituencies can be rather small, a dichotomisation might be misleading.It is also conventional wisdom today that the nature of the electoral system is not solely dependent on the electoral formula (Gallagher, 1991;Lijphart, 1994;Rae, 1967;Taagepera & Shugart, 1989).In particular, it has been emphasised that the district magnitude can be considered to be as important as explicit thresholds when evaluating the openness of a political system (Lijphart, 1994, p. 12).There are also studies that have found that the district magnitude is positively related to the electoral success of new parties (Willey, 1998).
In other words we cannot, a priori, infer that a country with an explicit threshold has a more closed electoral system than one without an explicit threshold without also taking into account the district magnitude.Furthermore, thresholds could be set both nationally and at constituency level.This might be of importance since, for instance, regionally based parties have better chances than parties with electoral support evenly distributed across the country if the seat distribution is mainly based on electoral results at constituency level (Bochsler, 2011).
In order to circumvent these technicalities, various electoral system measurements have been developed in order to scrutinise their openness (Ruiz-Rufino, 2007, 2011;Taagepera, 2002).In this study, Taagepera's (2002) Nationwide threshold of representation, T, will be employed.This measure indicates the percentage of votes a party must obtain in order to have a 50 per cent chance of winning at least one seat.The threshold is calculated according to where M is the district magnitude and S the parliament size.Since a country may have an explicit electoral threshold, this must of course be taken into account.Thus, the effective threshold is set at the higher of these two values. 1A couple of additional institutional factors have been identified as potentially important for explaining new party success.Firstly, it has been argued that the legislature-executive relations of a country matters (Hauss & Rayside, 1978;Willey, 1998).In a presidential system the winner-takes-all character of the presidential election tends to spill over to the parliamentary elections.Hauss and Rayside (1978, p. 37) argue, for instance, that when 'attention is focused on the single office of presidency, its zero-sum nature encourages the bipolarisation of the party system and makes it hard for weak parties … to compete effectively', while Meguid (2008, p. 8) asserts that 'voters do not want to support a candidate whose party is perceived to have no reasonable chance of winning the presidency'.
No presidential system exists in the data presented in this study; there are, however, some cases of semi-presidential systems.To test whether this influences the prospects for new parties, a dichotomous variable is included in the analysis to indicate whether the election is held in a semi-presidential system or not.
There is also a reason to analyse whether the vertical separation of powers is important.Willey (1998, p. 660) argues, for instance, that a new party needs less resources to succeed sub-nationally compared to nationally.In addition, local or regional electoral success may lead to a decreased psychological effect on voters.That is to say, the risk of casting a wasted vote becomes less prominent to the voters if the new party has a record of sub-national electoral success that shows that there is a real chance of parliamentary entry nationally as well (see also Müller-Rommel, 1998).To avoid losing too much information, the vertical separation of powers will not be measured according to the commonly applied dichotomy of unitary versus federal government.Since it is generally acknowledged that both unitary states and federations may vary in the extent to which their political systems are decentralised, the level of decentralisation is measured according to the Regional Authority Index (Hooghe, Marks, & Schakel, 2010).2 1 In this context it is important to emphasise that electoral systems are complex systems and comparisons between countries are difficult.There are several different measurements available to estimate the properties of electoral systems.Firstly, there are different measures of electoral system proportionality (Gallagher, 1991;Loosemore & Hanby, 1971;Rae, 1967).However, since these measures are indirectly dependent on whether a new party is elected or not, they are not suitable for this study.Secondly, since seats are allocated based on the number of votes at the constituency level, it has also been suggested that the analysis should primarily be conducted at this level (Bischoff, 2009;Selb & Pituctin, 2010).As the focus of this study is on national parliamentary entry, neither of these measures is suitable in this context.
Finally, two political system factors are also included in the analysis: turnout and voter volatility.Regarding turnout, there are well-grounded reasons to expect the level to be of importance.There are, however, mixed opinions about how it might matter.Some argue that small parties benefit from low turnout (Kestilä & Söderlund, 2007;van der Eijk, Franklin, & Marsh, 1996), the reason being that low turnout is a consequence of widespread discontent.Such discontent could be expressed either through abstention or a vote for a non-established party (Kestilä & Söderlund, 2007, p. 785).Mathematically, low turnout also decreases the absolute number of votes needed to overcome the electoral threshold (cf.second-order elections, Reif & Schmitt, 1980).Others argue the opposite (Bernhagen & Marsh, 2007;O'Malley, 2008;cf. Finseraas & Vernby, 2014).This line of argument does, however, depart from the notion that abstention is a strategic choice exercised when the voter is not expecting his/her preferred party to win a sufficient numbers of votes (Jackman, 1987).Consequently, high turnout might signify that voters are expressing their political discontent (Poguntke, 1996, p. 328).
Electoral volatility is also expected to promote new party parliamentary entry.This is perhaps best explained by a counterfactual.New parties will not win any votes if the established parties do not lose some votes.However, this expected correlation needs to be interpreted with some caution since the direction of correlation is not easily decided.In short, it might be hard to establish whether volatility causes new party parliamentary entry or whether it is a cause of the emergence of new parties.Regardless of the direction of the correlation, it seems to be a factor that is of interest.To test it, Pedersen's (1979) index of net volatility, V, is employed: where pi,t is the share of votes for party p at election t and n is the total number of parties.

Sociological factors
From a sociological perspective, political parties are regarded as a result of different groups requiring societal representation (Harmel & Robertson, 1985, p. 502).All other things being equal, it might be asserted that big countries therefore have a greater number of societal groups with political demands.Hence, we might expect there to be a correlation between the size of the country and new party parliamentary entry (cf.Tavits, 2006, p. 108).To test this claim, both population size and country area will be analysed.Due to the skew distribution, both these variables were transformed using the natural logarithm (ln) (Tabachnick & Fidell, 2006, pp. 86-88).
A second set of sociological factors deserving interest might be labelled socioeconomic or socio-cultural variables.There are, for instance, well-grounded arguments suggesting that new parties are facilitated by transformative events and societal unease.Such events, it is believed, cause discontent among voters, who spawn a demand for something new.To test this assertion, the analysis also includes economic indicators such as unemployment rates, inflation rates and economic growth rates (e.g.Arzheimer, 2009;Müller-Rommel, 1998).Changes in the demographic composition might also increase the attraction of new parties.There is, for example, some support for the claim that a high level of immigration explains radical right party success (Arzheimer, 2009;Golder, 2003).
The basic variables that were included in the statistical analyses, as well as references to the sources from which the information was taken, are listed in the appendix, in Table A1.

New party parliamentary entry across space and time
As this study deals with democratic politics in Western Europe, elections in Greece, Portugal and Spain prior to 1980 are excluded from the analysis.In all, 18 countries are included in the study.In these countries, 238 elections were held between 1960 and 2010.The distribution of the dependent variable is shown in Table 1.Sources: Mackie andRose (1991, 1997), Political data yearbook 1993-2010 (Katz et al., 1993(Katz et al., -2010)), Parties and Elections in Europe ( 2011), Nohlen and Stöver (2010).
The most common outcome is that no new party gained representation.New parties entered parliament in less than 50 per cent of the elections.In about 27 per cent of the elections, one new party entered the highest decision-making body, and there are an additional 13 per cent of cases in which two new parties passed the threshold of representation.
The table also shows that it is extremely rare that more than three new parties entered the parliament in the same election.Notably, six new parties entered the Italian lower chamber in 1994. 3The other two cases were Spain in 1986 (five new parties) and Belgium in 1978 (four new parties).
The number of new parties viewed in a comparative perspective is presented in Table 2. Overall, there were 175 new party parliamentary entries in the 238 elections held.In other words, on average, in three out of four elections just one new party was elected to parliament.Considering the number of parties without previous experience of representation that were actually running for parliament, the chances for the average party must be considered slim.This result shows significant differences between the countries in this study.While there were 21 new party parliamentary entries in the lower chambers of both Italy and Belgium, corresponding events were extremely rare in the German Bundestag.PDS, together with Die Grünen, were the only two German parties who fought their way into the German lower house during the period 1960-2010.A measure of association was calculated in order to statistically test the relationship between country and the number of new party parliamentary entries.With an eta-value of 0.41 there is evidence of a medium-strong correlation, indicating that there is an independent country effect.
There is also evidence of temporal variation (see Table 3).While there was about one new party parliamentary entries in every second election in the 1960s, this increased to almost one new party per election in the 1980s.During the last decade, however, there has been a significant change in this trend and we are now almost back to the same levels as at the beginning of the period.Compared to the spatial variation, the temporal variation is rather small (eta = 0.15).If the decrease in new party parliamentary entries is a trend or a coincidence remains to be seen.It should be noted, however, that the high levels in both the 1980s and the 1990s were, in part, the consequence of new party family formations.While the green parties were part of the 1980s' wave of new parties (e.g.Müller-Rommel, 1998), the disparate family of anti-immigration parties won electoral success during the period 1990-2000.Possibly, therefore, a completely new party family needs to be established if we are to see the same levels of new party parliamentary entries again.On the other hand, the green and antiimmigration parties make up only a minority of all new parties.
From descriptive inferences, I now turn to the matter of explaining new party parliamentary entry.

Explaining new party parliamentary entry
It has not been possible to collect data for all independent variables during the whole period of the study.As long as missing data are scattered randomly in the data matrix the generalisability is not affected to any great extent (Tabachnick & Fidell, 2006, p. 62).However, since the missing data largely pertain to specific years or countries and for a particular period of time, some measures have had to be introduced.For this reason, missing data regarding the variables for the Regional Authority Index, unemployment, economic growth, inflation and immigration have been replaced with values for the closest available period.If two values have occurred equally close in time then the mean of these was used.To test whether these replacement values have had an impact on the results, all analyses were also conducted on the original data set.No relevant differences were observed.
Since no new parties reached the threshold for being admitted to parliament entries in more than 50 per cent of the elections, the dependent variable is transformed into a dichotomised variable where 0 indicates no new party elected and 1 indicates that at least one new party was elected.Because of this, the analysis was carried out using multivariate logistic regression. 5Since the data are time-series cross-section with a binary dependent variable, there is a risk that the outcome of the dependent variable is not independent of previous outcomes.Such serial correlation might underestimate the true standard errors and thus may give rise to an overestimation of the strength of any correlation (Beck, Katz, & Tucker, 1998, pp. 1260-1261).To capture this, a first lag of the dependent variable was included in the analysis.
There seems to be no consensus about which measures best evaluate a logistic regression model (Garson, 2012).However, in order to provide sufficient information to evaluate the plausibility of the interpretations made, this study follows the recommendations of Peng et al. (2002).Firstly, information on whether each model performs better than a model with no predictors, the so-called null model, is presented.This is done by presenting a -2 log likelihood and associated chi-square values.A significant chi-square value signals that the model is significantly better than the null model (Tabachnick & Fidell, 2006, p. 448).Secondly, information is provided on how well the model performs using the Nagelkerke R square.Although this measure is not equivalent to the R-square value which is usually presented in OLS regression, it is often used to provide an intuitive picture of how well the model explains the phenomenon under study.The Nagelkerke R square is also supplemented with data on what proportion of the outcomes is correctly predicted.Finally, the individual independent variables are evaluated through the presentation of coefficients, significant tests and odds ratios in order to give an idea of how much each factor affects the probability of new party 5 An alternative to this would be to use a count model in which the dependent variable is the number of times something has occurred (Long, 1997, p. 217).Since new party entrances are rather rare events, the average of the dependent variable is close to 0 and similar to a Poisson distribution.However, a Poisson regression model assumes that each event must be independent of other events (King, 1998, p. 50) and that the variance of the dependent variable is equal to its mean (Dunteman & Ho, 2006, p. 23;Hoffmann, 2004, p. 104).Since these requirements are not met, the negative binomial distribution is a more appropriate statistical tool (Hoffmann, 2004, p. 12).In order to test the robustness of the logistic regressions, this regression model was also estimated.The result from this analysis provides no reason to change the overall conclusions drawn in this article.
parliamentary entry.To illustrate the probabilities, the presentation of the analysis is also illustrated with two graphs.
Table 4 presents the results of three logistic regressions.In the first model, the institutional factors are tested.The second model tests the sociological factors, while the third model includes all independent variables.The first aspect that is worth noting is that while both the institutional and the full models are significantly different from the null model, the sociological model is not (Chi square = 10.639,df = 7, p = 0.155).For this reason, the following presentation therefore focuses on the other two models.
With Nagelkerke R-square values of 0.16 and 0.18 and correctly predicted outcomes of 67.5 per cent (compared to 53.6 per cent in the null model) and 70 per cent (54.1 per cent) respectively, one might argue that the overall performance of the two models is rather moderate.To fully understand new party parliamentary entry, we might therefore conclude that other important factors exist, factors which are not included in the models.
The effective threshold and volatility both have significant and independent effects on new party parliamentary entry.While this is true for both the institutional model and the full model, it is also possible to conclude that turnout is significant in the latter.With a negative coefficient, support is given to the argument that increased turnout reduces the likelihood of new party parliamentary entry.It is also important to note that none of the sociological predictors reach the level of significance.
The odds ratios illustrate the importance of the individual explanatory factors for the probability of a new party entering parliament.In both the institutional and the full models the odds ratio for the effective threshold is about 0.7.This means that the odds of at least one new party entering parliament are reduced by almost 30 per cent and there is an increase in the effective threshold of one percentage point.
The odds ratios for volatility and voter turnout indicate that the effect of these variables is smaller.The odds for new party parliamentary entry are expected to increase by about 8 per cent if volatility is increased by one unit.The corresponding change in the odds is less than minus 3 per cent units for a 1 per cent unit increase in turnout.Small numbers, however, are not necessarily the same as marginal importance.In order to capture fully the extent to which these factors influence the chances of new party parliamentary entry, graphical presentation is helpful.Perhaps the easiest way to grasp an understanding of the significance of odds ratios is to convert them to probabilities and illustrate them in line graphs.Figure 1 and Figure 2 present the predicted probabilities that at least one new party enters parliament following the election.The graphs are derived from estimates in the full model, and each variable, apart from the two analysed in each figure, is held constant at its mean value.Figure 1 shows the plots for the predicted probability of new party parliamentary entry for three different levels of electoral volatility as well as for the effective threshold.The graph shows that the predicted probability of new party parliamentary entry when the electoral volatility is held at its mean (12 per cent) is about 70 per cent if no electoral threshold exists at all.With a mean effective threshold of 2.1 per cent the predicted probability of a new party parliamentary entry is about a 56 per cent chance.The figure also presents the predicted probabilities for the minimum and maximum values of electoral volatility.In Figure 2, three levels of turnout are plotted against effective thresholds.The line for the mean turnout is identical to the line for mean electoral volatility in Figure 1.
The graph illustrates that low turnout is expected to increase the chances of new party parliamentary entry.Actually, with a minimum turnout (42 per cent) and an effective threshold below 1.5 per cent, there is a predicted chance of more than 80 per cent for a new party parliamentary entry.However, these low levels of turnout are rare.Since turnout is somewhat unevenly dispersed (median = 82.8 per cent) it might therefore be interesting to compare the lines of the mean and the maximum turnout.Here, it can be observed that the differences between these lines are rather small.This indicates that the actual impact of turnout, albeit significant, is rather marginal.The overall impression of the statistical analysis is that the institutional perspective can, in part, explain new party parliamentary entry, while the sociological perspective is less supported in this study.In the final section these results are discussed and problematised.

Concluding remarks
The party systems of Western Europe are no longer frozen.Ever since the 1960s, new parties have been making inroads into national parliaments.The situation, however, is not the same in all countries.Whereas countries such as Italy and Belgium have experienced a veritable explosion of new parties in their national parliaments, other countries, most notably Germany, almost never experience new party parliamentary entry.While there might be many reasons for why this variation exists, this article has primarily dealt with the environment in which new parties attempt to win representation.Under the epithet of political opportunity structure, theoretically derived explanatory factors have been tested from both an institutional and a sociological perspective.The results are mixed.While the institutional perspective provides us with some explanatory power, the sociological perspective contributes less to our understanding.
The finding that the electoral system is important is hardly surprising and is well in line with prior research on related research questions such as what accounts for new party formation and electoral success (e.g.Hino, 2012;Willey, 1998).This finding is also of practical importance for policymakers.However, since constitutional politics, like any other policy area, is decided by the established parties, perhaps we should not expect this knowledge to be of much help for fledgling political parties.Much less so if we are to believe the abundance of literature on party cartelisation (e.g.Katz & Mair, 1995, 2009).As expected, there is also a strong relationship between electoral volatility and the occurrences of new party parliamentary entries.Perhaps more revealing is the fact that new parties seem to prosper when there is low turnout.While this has been suggested in previous studies, there are also many that have argued the opposite.From a new party perspective this finding might open up avenues of potential success, since low expected turnout, typical in so-called second-order elections, would enthuse full mobilisation.
There are several potential reasons for the poor results from the sociological perspective.Firstly, there might of course be methodological issues of concern: perhaps important explanatory factors have been omitted.Secondly, there is always a risk that secondary data fails to meet the strongest criteria of comparability.However, and perhaps most importantly, in the light of this study, the weak support for the sociological perspective suggests that there are few such factors that influence all new parties in the same way.While high levels of immigration might have an impact on the vote for anti-immigration parties, the same might not be true for, say, green parties.Also, while many argue that far right parties would prosper during an economic downturn, recent analysis suggests that they have not experienced any uniform electoral upswing despite the major financial crisis from 2008 onwards (Mudde, 2010).
It can be ascertained that, to some extent anyway, one of the aims of this paper, namely to find generic explanations for new party parliamentary entry, proved to be difficult to achieve.Therefore, one of the conclusions of this study is that although new parties share some similarities, we still need to differentiate between different groups in order to fully understand when and why they manage to gain representation.Furthermore, and regardless of the findings in this article, the political opportunity structure is just one side of the story.For new party parliamentary entry to occur, agency is also necessary and should therefore be taken into account (Bolin, 2012;Bolleyer 2013).Recent studies have, for instance, suggested that new party success is also dependent on both the actions taken by the established parties (e.g.Meguid, 2008) and the resources available to the new party (e.g.Lucardie, 2000).Of course, it is also important to note that new parties differ in terms of the extent to which they actually aim for parliamentary entry.While some parties are intrinsically vote-seeking and regard parliamentary entry as crucial, others primarily aim to put new or non-politicised issues on the agenda (cf.Strøm, 1990).Although there seems to be little to suggest that such goals do vary systematically between different countries, it is important to acknowledge that strategic considerations on behalf of new parties are also of relevance if we are to fully grasp why specific parties do or do not attain parliamentary representation.So, while this article has furthered our understanding of the importance of the external environment, more work needs to be done in order to gain systematic knowledge of the actions taken by new parties and to what extent these parties can be masters of their own destiny.

Figure 1 .
Figure 1.Predicted probabilities of new party parliamentary entry; effective threshold and volatility

Figure 2 .
Figure 2. Predicted probabilities of new party parliamentary entry; effective threshold and turnout

Table 1 .
Distribution of dependent variable, number of new party parliamentary entries in election

Table 4 .
Logistic regression: New parliamentary entry