Stefan Müller

Stefan Müller

Assistant Professor

University College Dublin

About Me

I am an Assistant Professor and Ad Astra Fellow in the School of Politics and International Relations at University College Dublin. Previously, I was a Senior Researcher at the University of Zurich. I hold a PhD in Political Science from Trinity College Dublin.

My research focuses on political representation, party competition, political communication, public opinion, quantitative text analysis, and the application of computer vision techniques. My work has been published or is forthcoming in journals such as The Journal of Politics, Political Communication, Political Science Research and Methods, and the European Journal of Political Research, among others.

I am a founding member of the Connected_Politics Lab, a non-resident fellow at the Digital Democracy Lab at the University of Zurich, a member of the UCD Energy Institute, and maintainer of the Irish Polling Indicator.

Full CV


Google Scholar Profile

Peer-Reviewed Journal Publications

Stefan Müller. Forthcoming. “The Temporal Focus of Campaign Communication.” The Journal of Politics.

Experiences from the past and present influence decision-making. Voting behavior at elections also involves retrospective and prospective considerations. Yet, we do not know the degree to which parties react to these considerations by emphasizing the past, present, and future. I posit that parties do not only make promises but face incentives to discuss the past and present. I also expect that incumbency status conditions emotive rhetoric across these temporal dimensions. Using supervised machine learning, I uncover the temporal rhetorical focus in 621 party manifestos published in nine countries between 1949 and 2017. Parties devote, on average, half of a manifesto to future promises, while the other half describes the past and present. Besides, I show that statements on the past and present drive previously observed differences in sentiment between incumbents and opposition parties. The findings underscore how the temporal dimension of campaign communication enhances our understanding of party competition.

Fabrizio Gilardi, Theresa Gessler, Maël Kubli, and Stefan Müller. Forthcoming. “Social Media and Policy Responses to the COVID-19 Pandemic in Switzerland.” Swiss Political Science Review.

We study the role of social media in debates regarding two policy responses to COVID‐19 in Switzerland: face‐mask rules and contact‐tracing apps. We use a dictionary classifier to categorize 612,177 tweets by parties, politicians, and the public as well as 441,458 articles published in 76 newspapers between February and August 2020. We distinguish between “problem” (COVID‐19) and “solutions” (face masks and contact‐tracing apps) and, using a vector autoregression approach, we analyze the relationship between their salience on social and traditional media, as well as among different groups on social media. We find that overall attention to COVID‐19 was not driven by endogenous dynamics between the different actors. By contrast, the debate on face masks was led by the attentive public and by politicians, whereas parties and newspapers followed. The results illustrate how social media challenge the capacity of party and media elites to craft a consensus regarding the appropriateness of different measures as responses to a major crisis.

Michael Jankowski and Stefan Müller. 2021. “The Incumbency Advantage in Second-Order PR Elections: Evidence from the Irish Context, 1942–2019.” Electoral Studies (online first).

Do candidates in local elections benefit from an incumbency advantage? And which factors moderate the strength of this incumbency bonus? Analyzing seven decades of Irish local elections (1942–2019) conducted under proportional representation through the single transferable vote, we reassess and extend the mixed evidence on the incumbency advantage under proportional representation and in second-order elections. By applying the Regression Discontinuity Design, we find that the incumbency advantage is at least as strong in Irish local as in general elections, which are conducted under the identical electoral system. We also show that marginally elected candidates in local elections have much higher reelection probabilities when they do not face a high-quality candidate in their local electoral area after getting elected. The findings point to the importance of name recognition as a major driver of the incumbency advantage in local elections.

Fabrizio Gilardi, Theresa Gessler, Maël Kubli, and Stefan Müller. 2021. “Social Media and Political Agenda Setting.” Political Communication (online first).

What is the role of social media in political agenda setting? Digital platforms have reduced the gatekeeping power of traditional media and, potentially, they have increased the capacity of various kinds of actors to shape the agenda. We study this question in the Swiss context by examining the connections between three agendas: the traditional media agenda, the social media agenda of parties, and the social media agenda of politicians. Specifically, we validate and apply supervised machine learning classifiers to categorize 2.78 million articles published in 84 newspapers, 6,500 tweets posted on official party accounts, and 210,000 tweets posted by politicians on their own accounts from January 2018 until December 2019. We first use the classifier to measure the salience of the four most relevant issues of the period: the environment, Europe, gender equality, and immigration. Then, using a vector autoregression (VAR) approach, we analyze the relationship between the three agendas. Results show that not only do the traditional media agenda, the social media agenda of parties, and the social media agenda of politicians influence one another but, overall, no agenda leads the others more than it is led by them. There is one important exception: for the environment issue, the social media agenda of parties is more predictive of the traditional media agenda than vice-versa. These findings underscore how closely different agendas are tied together, but also show that advocacy campaigns may play an important role in both constraining and enabling parties to push their specific agendas.

Shaun Bowler, Gail McElroy, and Stefan Müller. 2021. “Voter Expectations of Government Formation in Coalition Systems: The Importance of the Information Context.” European Journal of Political Research (online first).

Can voters in multi-party systems predict which coalition will form the government with any degree of accuracy? To date, studies which explore voter expectations of coalition formation have emphasized individual level attributes, such as education, but the context of information that voters experience at the time the coalitions are forming should also be consequential in enabling (or handicapping) voters in forming expectations. We examine the relative effects of individual level attributes (e.g. education, cognitive mobilization) versus contextual factors (e.g. information availability) in 19 German state elections and 3 German general elections between 2009 and 2017. We find that the ease of identifiability of alternative future governments varies significantly across multi-party systems. We find that respondents are more likely to predict governments that they would like to see in office, that have a higher probability of receiving a majority of seats, and that consist of ideologically proximate parties. Combining survey data with a novel indicator of coalition signals, measured through a quantitative text analysis of newspaper coverage, we also find that voters consider positive pre-election coalition signals when predicting the government. Finally, we find that the information environment is much more relevant for correct coalition predictions than individual-level characteristics of respondents. While individual attributes do influence predictive ability, these factors are strongly dominated by the context in which the prediction is taking place. The information environment has by far the largest effect on predicting coalition outcomes. Our results have implications for the literature on strategic voting in multiparty settings, as well as the literature on accountability.

Stefan Müller. 2020. “Media Coverage of Campaign Promises Throughout the Electoral Cycle.” Political Communication 37(5): 696–718.

Previous studies conclude that governments fulfill a large share of their campaign pledges. However, only a minority of voters believe that politicians try to keep their promises, and many voters struggle to recall the fulfillment or breaking of salient campaign pledges accurately. I argue that this disparity between the public perception and empirical evidence is influenced by the information voters receive throughout the electoral cycle. I expect that the media extensively inform readers about political promises. In addition, I posit that news outlets focus more on broken than on fulfilled promises and that the focus on broken promises has increased over time. I find strong support for these expectations based on a new text corpus of over 430,000 statements on political commitments published between 1979 and 2017 in 22 newspapers during 33 electoral cycles in Australia, Canada, Ireland, and the United Kingdom. Newspapers inform voters regularly about announced, broken, and fulfilled promises. Yet, across the four countries, newspapers report at least twice as much on broken than on fulfilled promises. Moreover, this negativity bias in reports on political promises has increased substantively. The results have implications for studying campaign promises, negative information in mass media, and the linkages between voters and parties.

Stefan Müller and Tom Louwerse. 2020. “The Electoral Cycle Effect in Parliamentary Democracies.” Political Science Research and Methods 8(4): 795–802.

Does government party support decline in a monotonic fashion throughout the legislative cycle or do we observe a u-shaped 'electoral cycle effect'? Moving beyond the study of midterm election results, this is the first study to assess the cyclical pulse of government party support in parliamentary democracies based on over 25,000 voting intention polls from 171 cycles in 22 countries. On average, government parties lose support during the first half of the electoral cycle, but at most partially recover from their initial losses. Under single-party government and when prime ministers control cabinet dissolution, support tends to follow the previously assumed u-shaped pattern more strongly. Finally, we find that government parties hardly recover from early losses since the 2000s.

Shaun Bowler, Gail McElroy, and Stefan Müller. 2020. “Campaigns and the Selection of Policy-Seeking Representatives.” Legislative Studies Quarterly 45(3): 397–431.

Can voters learn meaningful information about candidates from their electoral campaigns? As with job market hiring, voters, like employers, cannot know the productivity of candidates, especially challengers, when they elect them. The real productivity of representatives only reveals itself after the election. We explore if the information revealed during the "hiring process" is a good signal of the legislative effort of elected representatives. In the incomplete information environment of election campaigns, candidates should turn to credible signals to indicate their "type" to voters. Campaigns – and campaigning – are means by which candidates can, in principle, signal their motivations to voters. Is a candidate's behavior on the campaign trail informative about their behavior and effort as a legislator? Does it, for example, reveal whether a candidate will be more hard working and legislatively active? Using evidence from the European Parliament we show that campaign activity prior to the election is not related to policy-seeking behavior in the legislature post-election. The finding also holds in two national-level settings and across a variety of measures of legislative effort. Those who campaign harder do seem more likely to win the election, but campaign effort seems to provide a poor guide to what the winner does once elected.

Stefan Müller and Michael Jankowski. 2019. “Do Voters Really Prefer More Choice? Determinants of Support for Personalised Electoral Systems.” Journal of Elections, Public Opinion and Parties 29(2): 262–281.

Which voters prefer having more choice between parties and candidates in an election? To provide an answer to this question, we analyse the case of a radical change from a closed-list PR system to a highly complex open-list PR system with cumulative voting in the German states of Bremen and Hamburg. We argue that the approval of a personalised electoral system is structured in similar ways as support for direct democracy. Using representative surveys conducted prior to all four state elections under cumulative voting in 2011 and 2015, we analyse which individual factors determine the approval, disapproval or indifference towards the new electoral law. The results indicate that younger voters as well as supporters of left parties are much more likely to support a personalised electoral system. In contrast to previous studies, political interest only has an impact on the indifference towards the electoral system. More generally, our results show that a large proportion of voters does not appreciate personalised preferential electoral systems which seems to be a result of the complexity and magnitude of choice between parties and candidates.

Kenneth Benoit, Kohei Watanabe, Haiyan Wang, Paul Nulty, Adam Obeng, Stefan Müller, and Akitaka Matsuo. 2018. “quanteda: An R Package for the Quantitative Analysis of Textual Data.” Journal of Open Source Software 3(30): 774.

quanteda is an R package providing a comprehensive workflow and toolkit for natural language processing tasks such as corpus management, tokenization, analysis, and visualization. It has extensive functions for applying dictionary analysis, exploring texts using keywords-in-context, computing document and feature similarities, and discovering multi-word expressions through collocation scoring. Based entirely on sparse operations, it provides highly efficient methods for compiling document-feature matrices and for manipulating these or using them in further quantitative analysis. Using C++ and multi-threading extensively, quanteda is also considerably faster and more efficient than other R and Python packages in processing large textual data.

Shaun Bowler, Gail McElroy, and Stefan Müller. 2018. “Voter Preferences and Party Loyalty under Cumulative Voting: Political Behaviour after Electoral Reform in Bremen and Hamburg.” Electoral Studies 51: 93–102.

Many electoral systems constrain voters to one or two votes at election time. Reformers often see this as a failing because voters' preferences are both broader and more varied than the number of choices allowed. New electoral systems therefore often permit more preferences to be expressed. In this paper we examine what happens when cumulative voting is introduced in two German states. Even when we allow for tactical considerations, we find that the principle of unconstrained choice is not widely embraced by voters, although in practice, too, many seem to have preferences for more than just one party. This finding has implications for arguments relating to electoral reform as well as how to conceive of party affiliations in multi-party systems.

Liam Kneafsey and Stefan Müller. 2018. “Assessing the Influence of Neutral Grounds on Match Outcomes.” International Journal of Performance Analysis in Sport 18(6): 892–905.

The home advantage in various sports has been well documented. So far, we lack knowledge whether playing in neutral venues indeed removes many, if not all, theoretically assumed advantages of playing at home. Analysing over 3,500 senior men’s Gaelic football and hurling matches – field games with the highest participation rates in Ireland – between 2009 and 2018, we test the potential moderating influence of neutral venues. In hurling and Gaelic football, a considerable share of matches is played at neutral venues. We test the influence of neutral venues based on descriptive statistics, and multilevel logistic and multinomial regressions controlling for team strength, the importance of the match, the year, and the sport. With predicted probabilities ranging between 0.8 and 0.9, the favourite team is very likely to win home matches. The predicted probability drops below 0.6 for away matches. At neutral venues, the favourite team has a predicted probability of winning of 0.7. A Coarsened Exact Matching (CEM) approach also reveals very substantive and significant effects for the “treatment” of neutral venues. Overall, neutral venues appear to be an under-utilised option for creating fairer and less predictable competition, especially in single-game knockout matches.

Other Publications

Kohei Watanabe and Stefan Müller. 2021. Quanteda Tutorials.

Current Research

Papers Under Review

Evidence for the Irrelevance of Irrelevant Events. Political Science Research and Methods: revise & resubmit (with Liam Kneafsey).

The expectation that voters behave rationally has been challenged through studies suggesting that ‘irrelevant events’ like natural disasters and sports results change voting behavior. We test the effect of irrelevant events by matching candidate-level election results from Irish general (1922–2020) and local elections (1942–2019) with games in the Gaelic football and hurling championships, the most popular sports in Ireland. Although Irish citizens care deeply about sports, a difference-in-differences design fails to find any relationship between match results and support for incumbents or politicians of government parties. These findings hold when applying an ‘unexpected event during survey design’ to two representative surveys. Our results contribute to the literature on political accountability and point to conditional effects of irrelevant events.

Gender, Candidate Emotional Expression, and Voter Reactions During Televised Debates (with Constantine Boussalis, Travis G. Coan, and Mirya R. Holman).

Voters evaluate politicians not just by what they say, but also how they say it, via facial displays of emotions and vocal pitch. Candidate characteristics can shape how leaders use—and how voters react to—nonverbal cues. Drawing on role congruity expectations, we study how the use of and reactions to facial, vocal, and textual communication in political debates varies by candidate gender. Relying on full-length videos of four German federal election debates (2005–2017) and a minor party debate, we use video, audio, and text data to measure candidate facial displays of emotion, vocal pitch, and speech sentiment. Consistent with our expectations, Angela Merkel expresses less anger than her male opponents, but is just as emotive in other respects. Combining these measures of emotional expression with continuous responses recorded by live audiences, we find that voters punish Merkel for anger displays and reward her happiness and general emotional displays.

Building Research Infrastructures to Study Digital Technology and Politics: Lessons from Switzerland (with Fabrizio Gilardi, Lucien Baumgartner, Clau Dermont, Karsten Donnay, Theresa Gessler, Maël Kubli, and Lucas Leemann).

The effects of digital technology on political processes is an important phenomenon that, due to several structural problems, remains poorly understood. A key problem is the lack of adequate research infrastructures to study digital technology and politics, or the lack of access. We first discuss the challenges many social scientists face and then present the infrastructure we built in Switzerland to overcome them, using COVID-19 as an example. We conclude by discussing seven lessons we learned: automatization is key; avoid data hoarding; outsource some parts of the infrastructure, but not others; focus on substantive questions; share data in the context of collaborations; engage in targeted public outreach; collaboration beats competition. We hope that our experience will be helpful to other researchers pursuing similar goals.

The Compass of Irish Politics is Moving to the Left (with Aidan Regan).

It has often been assumed that Ireland is an outlier in comparative politics. It never had a left-right divide in parliament, and for decades, the dominant centrist political parties competed around a centre-right policy agenda. The absence of an explicit left-right divide in party competition and parliament was assumed to mean that Irish voters, on average, occupy centre-right policy preferences. The dominant parties were simply responding to what the average voter wanted. Using the 2020 Irish electoral survey and data from all Irish election studies since 2002, we show that this is no longer the case. The average Irish voter now leans to the centre-left. This self-identification on the left is consistent with policy preferences on taxes, spending, and government interventions to reduce inequality. This left-leaning trend is consistent even when Sinn Féin voters are excluded from the data, or when using a different survey that explicitly explains to respondents the substantive meaning of the left-right dimension. We show who exactly these growing voters are, and whom they are voting for. The paper analyses different theoretical arguments to explain why this leftward shift has taken place, and concludes that it is related to economic conflict and the changing class-based structure of the Irish political economy, and the emergence of Sinn Féin as the main opposition party.

Issue Ownership and Agenda Setting in the 2019 Swiss National Elections (with Fabrizio Gilardi, Theresa Gessler, and Maël Kubli).

The 2019 Swiss national elections were characterized by the unusual prominence of two issues, environment and gender, whereas two staples of Swiss politics, immigration and Europe, remained in the background. We study how, in this context, the campaign agenda was linked to issue ownership. Specifically, we consider whether political parties that own an issue could lead the media agenda and the agenda of other parties. Our analysis relies on all tweets and press releases of major Swiss political parties from January until October 2019, as well as 36,415 newspaper articles published during the same period. Results show that the agenda-setting capacity of parties was restricted to the issue that received the least attention during the campaign, namely gender. Moreover, the link between issue ownership and agenda setting is ambiguous. These findings show that during election campaigns, which issues dominate the agenda may be largely exogenous to both parties and media.

Ongoing Projects

Discourse Power and Image Management: China’s Covid-19 ‘Mask Diplomacy’ and the Global Response (with Samuel Brazys and Alexander Dukalskis).

Explaining (In)Congruence Between Politicians’ Campaign Promises and Subsequent Legislative Priorities (with Naofumi Fujimura).

Causes and Electoral Effects of Nostalgic Rhetoric: A Cross-National Analysis of Party Communication (with Sven-Oliver Proksch).

Do Candidates Tweet About Oirish Sheep? Examining the Irish #GE2020 Campaign on Social Media Using an Images-as-Data Approach (with Mark Belford, James P Cross, Derek Greene, and Martijn Schoonvelde).

If you would like to get access to the latest version of a paper, feel free to send me an e-mail.


Module Instructor: Undergraduate Level

Module Instructor: Postgraduate Level

Workshop Instructor

Irish Polling Indicator

The Irish Polling Indicator is a joint project with Tom Louwerse. We combine all opinion polls for the Dáil Éireann into daily estimates of public support for Irish parties. The website of the Polling Indicator provides various visualisations and detailed information on the underlying method.

The figure below (updated automatically after the release of new polls) summarises the most recent estimates of party support:

Curriculum Vitae

Full CV (PDF)

Academic Positions

2020– Assistant Professor and Ad Astra Fellow
University College Dublin
School of Politics and International Relations
Connected_Politics Lab (founding member)
2019–2020 Senior Researcher (Oberassistent)
University of Zurich, Department of Political Science


2015–2018 PhD in Political Science
Trinity College Dublin, Department of Political Science
2017–2018 Postgraduate Certificate in Statistics
Trinity College Dublin, School of Computer Science and Statistics
2014–2015 Master of Science in Politics and Public Policy
Trinity College Dublin, Department of Political Science
2011–2014 Bachelor of Arts in Political Science and Sociology
University of Bonn, Department of Political Science and Sociology

Visiting Positions

2020– University of Zurich, Digital Democracy Lab
2019 Kobe University, Graduate School of Law
2019 Trinity College Dublin, Department of Political Science
2018 EUROLAB at GESIS – Leibniz Institute for the Social Sciences, Cologne