COVID | Heike Klüver

summary

This project explores how the COVID-19 pandemic has shaped public opinion and political behavior. Combining two complementary strands of research, the project investigates how citizens navigate complex policy trade-offs during crises and how these experiences have affected Euroscepticism, European solidarity, and support for international cooperation. Using a multi-method approach—including large-scale surveys, survey experiments, geocoded data, and natural language processing—the project examines both cross-national variation and in-depth evidence from Germany. Key areas of inquiry include the impact of policy measures and political communication on public trust, attitudes toward vaccination and civil liberties, and preferences for global vaccine distribution. The findings reveal that citizens are more supportive of restrictive and international measures when framed as effective, fair, and solidarity-based. This project offers critical insights into crisis governance, democratic resilience, and the evolving legitimacy of supranational institutions in times of uncertainty.

Research in this area has been (partly) funded by:

related publications

2025

The Political Effects of Communicative Interventions During Crises

Asli Unan, Heike Klüver, Sara Hobolt, and Toni Rodon

European Journal of Political Research, Nov 2025

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Can communicative interventions by the government influence political trust and increase public compliance during crises? This study examines the impact of a televised speech by German Chancellor Angela Merkel at the onset of the COVID‐19 pandemic. Using an unexpected‐events‐during‐survey‐design, we find that the speech led to a 7‐percentage point increase in trust in the federal government and up to a 25‐percentage point decrease in citizens’ mobility. We also observe demographic variation in susceptibility to speech. We explore the underlying mechanisms by comparing Merkel’s speech with similar televised addresses by Mark Rutte and Boris Johnson, where we observe no comparable effects on attitudes. We suggest that specific content, such as an emphasis on solidarity and positive sentiment, may have played a role in mobilizing public support. Our findings indicate that effective leader communication can be a powerful tool for sustaining public support and ensuring compliance with crisis measures.
@article{unan_political_2025, title = {The {Political} {Effects} of {Communicative} {Interventions} {During} {Crises}}, author = {Unan, Asli and Klüver, Heike and Hobolt, Sara and Rodon, Toni}, year = {2025}, month = nov, journal = {European Journal of Political Research}, volume = {64}, number = {4}, pages = {2039--2050}, doi = {10.1111/1475-6765.70020}, issn = {0304-4130, 1475-6765}, url = {https://ejpr.onlinelibrary.wiley.com/doi/10.1111/1475-6765.70020}, urldate = {2025-06-06}, language = {en}, data = {https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/JFYMOK}, }
Closed Borders, Closed Minds? COVID‐Related Border Closures, EU Support and Hostility Towards Immigrants

Lisa Herbig, Asli Unan, Theresa Kuhn, Irene Rodríguez, Toni Rodon, and Heike Klüver

European Journal of Political Research, Nov 2025

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Do border closures affect political attitudes? While a large body of research has discussed the effects of the COVID‐19 pandemic on nationalism and outgroup hostility, much less is known about how one of the main policy responses to stop the virus, closing the national borders, has impacted political attitudes. We argue that the sudden and unprecedented closures of national borders in the COVID‐19 crisis decreased EU support and increased hostility towards immigrants. These closures signalled that people from across the border are a threat to public health and showed little trust in European governance. We have collected fine‐grained regional data on COVID‐19‐related border closures in Germany that we matched with survey data from the German Socio‐Economic Panel. We rely on a difference‐in‐differences design to estimate the causal effect of closed borders on European identity and outgroup hostility. While we find that border closures decrease EU support and increase hostility towards immigrants, these effects fade away relatively quickly. Hence, our study suggests that border closures have only limited impact on political attitudes. Our findings have important implications for the growing literature on border politics in the EU and elsewhere.
@article{herbig_closed_2025, title = {Closed {Borders}, {Closed} {Minds}? {COVID}‐{Related} {Border} {Closures}, {EU} {Support} and {Hostility} {Towards} {Immigrants}}, shorttitle = {Closed {Borders}, {Closed} {Minds}?}, author = {Herbig, Lisa and Unan, Asli and Kuhn, Theresa and Rodríguez, Irene and Rodon, Toni and Klüver, Heike}, year = {2025}, month = nov, journal = {European Journal of Political Research}, volume = {64}, number = {4}, pages = {1923--1944}, doi = {10.1111/1475-6765.70025}, issn = {0304-4130, 1475-6765}, url = {https://ejpr.onlinelibrary.wiley.com/doi/10.1111/1475-6765.70025}, urldate = {2025-06-05}, language = {en}, data = {https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/4NWUDL}, }
Europeans’ Attitudes Toward the EU Following Russia’s Invasion of Ukraine

Asli Unan and Heike Klüver

Political Science Research and Methods, Oct 2025

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The Russian invasion of Ukraine in February 2022 has had profound effects on the stability and security of Europe. This study examines the attitudes of Europeans toward the European Union (EU) in the aftermath of the invasion of Ukraine. Using Special Eurobarometer data collected between February and April 2022 with a representative sample of the EU (N = 26,502), it leverages the quasi-experimental setting with the coincidence between the timing of the invasion and the fieldwork period of the Eurobarometer. Our findings indicate a general increase in support for the EU in the aftermath of the invasion by 4 percentage-points (11 percent of a SD). While the amplitude of the effect remains similar, we see larger treatment effects as more days passed after the invasion. We also observe significant variation at the individual level in treatment effects, particularly by ideology, with left-leaning individuals being more critical of the EU following the invasion. In general, our research demonstrates the significant impact of regional conflicts on public attitudes toward supranational organizations such as the EU and highlights the role of the EU as a provider of security and stability in the face of such conflicts.
@article{unan_europeans_2024, title = {Europeans’ {Attitudes} {Toward} the {EU} {Following} {Russia}'s {Invasion} of {Ukraine}}, author = {Unan, Asli and Klüver, Heike}, year = {2025}, month = oct, journal = {Political Science Research and Methods}, volume = {13}, number = {4}, pages = {1025--1030}, doi = {10.1017/psrm.2024.62}, issn = {2049-8470, 2049-8489}, url = {https://www.cambridge.org/core/product/identifier/S2049847024000621/type/journal_article}, urldate = {2025-05-15}, copyright = {http://creativecommons.org/licenses/by/4.0/}, language = {en}, data = {https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/WRLXWI}, }
Benchmarking Pandemic Response: How the UK’s COVID-19 Vaccine Rollout Impacted Diffuse and Specific Support for the EU

Irene Rodríguez, Toni Rodon, Asli Unan, Lisa Herbig, Heike Klüver, and Theresa Kuhn

British Journal of Political Science, Oct 2025

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Does the EU’s performance compared to neighboring countries influence public support? Using a benchmarking approach, we argue that people compare their country’s performance within the EU to that of a non-EU country, shaping their attitudes. The COVID-19 vaccine rollout in 2020 provides an ideal test case, as governments launched vaccination programs at different speeds. The UK began weeks before EU countries, allowing us to examine its impact on EU support. Using an Unexpected Event during Surveys Design (UESD) with Eurobarometer data, we find that the UK’s early rollout significantly reduced specific policy support for the EU but did not consistently affect diffuse support. Our findings offer key insights into attitudes toward European integration and performance evaluations.
@article{rodriguez_benchmarking_2025, title = {Benchmarking {Pandemic} {Response}: {How} the {UK}’s {COVID}-19 {Vaccine} {Rollout} {Impacted} {Diffuse} and {Specific} {Support} for the {EU}}, shorttitle = {Benchmarking {Pandemic} {Response}}, author = {Rodríguez, Irene and Rodon, Toni and Unan, Asli and Herbig, Lisa and Klüver, Heike and Kuhn, Theresa}, year = {2025}, journal = {British Journal of Political Science}, volume = {55}, pages = {e35}, doi = {10.1017/S0007123424000802}, issn = {0007-1234, 1469-2112}, url = {https://www.cambridge.org/core/product/identifier/S0007123424000802/type/journal_article}, urldate = {2025-05-15}, copyright = {https://creativecommons.org/licenses/by/4.0/}, language = {en}, data = {https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/D6JI4M}, }

2024

Policy Revisions During Crisis: The Impact on Voter Trust in Government

Felix Hartmann, Macartan Humphreys, Ferdinand Geissler, Heike Klüver, and Johannes Giesecke

Aug 2024

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Recent literature has explored the impact of policy reversals on citizens’ attitudes towards the government, mostly finding negative effects. We contribute to research exploring whether scientifically supported policy updates from apolitical public authorities can mitigate negative backlash. Drawing on an information experiment conducted among 10,500 citizens in Germany, we find that inconsistent advice adversely affects perceived credibility and competence of the government and that prior trust does not influence this effect. Exposing citizens to information about the scientific process and the normalcy of changing recommendations yields a positive but insignificant effect. In a second analysis, we study the implications of this for policymaking. We analyze public health policy changes in the context of the Covid-19 crisis across 65 countries and find that incumbents who face electoral pressure indeed change their recommendations less often. Taken together, the results suggest that governments in democracies face a difficult-to-resolve trade-off between electoral support and public welfare once new, inconsistent evidence becomes available.
@misc{hartmann_policy_2024, title = {Policy {Revisions} {During} {Crisis}: {The} {Impact} on {Voter} {Trust} in {Government}}, shorttitle = {Policy {Revisions} {During} {Crisis}}, author = {Hartmann, Felix and Humphreys, Macartan and Geissler, Ferdinand and Klüver, Heike and Giesecke, Johannes}, year = {2024}, month = aug, publisher = {Open Science Framework}, doi = {10.31219/osf.io/7gqrt}, url = {https://osf.io/7gqrt}, urldate = {2025-05-09}, copyright = {https://creativecommons.org/licenses/by/4.0/legalcode}, }
Trading Liberties: Estimating COVID-19 Policy Preferences from Conjoint Data

Felix Hartmann, Macartan Humphreys, Ferdinand Geissler, Heike Klüver, and Johannes Giesecke

Political Analysis, Apr 2024

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Survey experiments are an important tool to measure policy preferences. Researchers often rely on the random assignment of policy attribute levels to estimate different types of average marginal effects. Yet, researchers are often interested in how respondents trade-off different policy dimensions. We use a conjoint experiment administered to more than 10,000 respondents in Germany, to study preferences over personal freedoms and public welfare during the COVID-19 crisis. Using a pre-registered structural model, we estimate policy ideal points and indifference curves to assess the conditions under which citizens are willing to sacrifice freedoms in the interest of public well-being. We document broad willingness to accept restrictions on rights alongside sharp heterogeneity with respect to vaccination status. The majority of citizens are vaccinated and strongly support limitations on freedoms in response to extreme conditions—especially, when they vaccinated themselves are exempted from these limitations. The unvaccinated minority prefers no restrictions on freedoms regardless of the severity of the pandemic. These policy packages also matter for reported trust in government, in opposite ways for vaccinated and unvaccinated citizens.
@article{hartmann_trading_2024, title = {Trading {Liberties}: {Estimating} {COVID}-19 {Policy} {Preferences} from {Conjoint} {Data}}, shorttitle = {Trading {Liberties}}, author = {Hartmann, Felix and Humphreys, Macartan and Geissler, Ferdinand and Klüver, Heike and Giesecke, Johannes}, year = {2024}, month = apr, journal = {Political Analysis}, volume = {32}, number = {2}, pages = {294--294}, doi = {10.1017/pan.2023.29}, issn = {1047-1987, 1476-4989}, url = {https://www.cambridge.org/core/product/identifier/S1047198723000293/type/journal_article}, urldate = {2025-05-09}, copyright = {https://creativecommons.org/licenses/by/4.0}, language = {en}, data = {https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/SVD9SV}, }

2022

Public Support for Global Vaccine Sharing in the COVID-19 Pandemic: Evidence from Germany

Ferdinand Geissler, Felix Hartmann, Macartan Humphreys, Heike Klüver, and Johannes Giesecke

PLOS ONE, Dec 2022

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By September 2021 an estimated 32% of the global population was fully vaccinated for COVID-19 but the global distribution of vaccines was extremely unequal, with 72% or more vaccinated in the ten countries with the highest vaccination rates and less than 2% in the ten countries with the lowest vaccination rates. Given that governments need to secure public support for investments in global vaccine sharing, it is important to understand the levels and drivers of public support for international vaccine solidarity. Using a factorial experiment administered to more than 10,000 online survey respondents in Germany in 2021, we demonstrate that the majority of German citizens are against global inequalities in vaccine distribution. Respondents are supportive of substantive funding amounts, on the order of the most generous contributions provided to date, though still below amounts that are likely needed for a successful global campaign. Public preferences appear largely to be driven by intrinsic concern for the welfare of global populations though are in part explained by material considerations—particularly risks of continued health threats from a failure to vaccinate globally. Strategic considerations are of more limited importance in shaping public opinion; in particular we see no evidence for free riding on contributions by other states. Finally, drawing on an additional survey experiment, we show that there is scope to use information campaigns highlighting international health externalities to augment public support for global campaigns.
@article{geissler_public_2022, title = {Public {Support} for {Global} {Vaccine} {Sharing} in the {COVID}-19 {Pandemic}: {Evidence} from {Germany}}, shorttitle = {Public {Support} for {Global} {Vaccine} {Sharing} in the {COVID}-19 {Pandemic}}, author = {Geissler, Ferdinand and Hartmann, Felix and Humphreys, Macartan and Klüver, Heike and Giesecke, Johannes}, year = {2022}, month = dec, journal = {PLOS ONE}, volume = {17}, number = {12}, pages = {e0278337}, doi = {10.1371/journal.pone.0278337}, issn = {1932-6203}, url = {https://dx.plos.org/10.1371/journal.pone.0278337}, urldate = {2025-05-09}, language = {en}, editor = {Rubinelli, Sara}, data = {https://wzb-ipi.github.io/vaccine_solidarity/}, }

2021

Incentives Can Spur COVID-19 Vaccination Uptake

Heike Klüver, Felix Hartmann, Macartan Humphreys, Ferdinand Geissler, and Johannes Giesecke

Proceedings of the National Academy of Sciences, Sep 2021

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Recent evidence suggests that vaccination hesitancy is too high in many countries to sustainably contain COVID-19. Using a factorial survey experiment administered to 20,500 online respondents in Germany, we assess the effectiveness of three strategies to increase vaccine uptake, namely, providing freedoms, financial remuneration, and vaccination at local doctors. Our results suggest that all three strategies can increase vaccination uptake on the order of two to three percentage points (PP) overall and five PP among the undecided. The combined effects could be as high as 13 PP for this group. The returns from different strategies vary across age groups, however, with older cohorts more responsive to local access and younger cohorts most responsive to enhanced freedoms for vaccinated citizens.
@article{kluver_incentives_2021, title = {Incentives {Can} {Spur} {COVID}-19 {Vaccination} {Uptake}}, author = {Klüver, Heike and Hartmann, Felix and Humphreys, Macartan and Geissler, Ferdinand and Giesecke, Johannes}, year = {2021}, month = sep, journal = {Proceedings of the National Academy of Sciences}, volume = {118}, number = {36}, doi = {10.1073/pnas.2109543118}, url = {https://www.pnas.org/doi/abs/10.1073/pnas.2109543118}, language = {en}, data = {https://wzb-ipi.github.io/covid_hesitancy_2021/}, }