Who Refers to Science? Understanding the Use of Scientific Evidence in Parliamentary Debates

Effective politics relies on the availability and use of factual information. Indeed, scientific evidence is widely regarded as a key ingredient in rational, informed political decisions (Boswell & Smith, 2017). However, while theoretical and normative discussions often stress the importance of evidence-informed politics, empirical studies of how often and under what conditions politicians refer to scientific evidence in their argumentation remain limited (Qadir & Syväterä, 2021). In particular, comparative large-scale analyses across countries are scarce. This study aims to fill this gap by analyzing references to scientific evidence in one important arena of policymaking: parliamentary speeches. Our dataset covers 30,000 speeches delivered in the main legislative chambers across six European democracies (Austria, Czechia, Denmark, Finland, Italy, and the United Kingdom) from 2018 to 2021, offering both a sufficient pre-pandemic baseline and the opportunity to assess whether a global crisis with high scientific relevance altered the role of science in political discourse. Using large language models (LLMs), we identify two key features in each speech: (1) the presence or absence of references to scientific evidence, and (2) the primary policy issue, coded using the 21-category Comparative Agendas Project framework (Jones et al., 2023). We then apply logistic regression models to evaluate which factors are associated with higher or lower likelihoods of science references. We distinguish between three sets of predictors: (a) macro-level country variables, (b) meso-level party and issue factors, and (c) micro-level speaker characteristics. Findings suggest that institutional roles, policy contexts, and organizational routines are more decisive for evidence use in politics than national context or ideology. References Boswell, C., & Smith, K. (2017). Rethinking policy ‘impact’: Four models of research-policy relations. Palgrave Communications, 3(1), 44. https://doi.org/10.1057/s41599-017-0042-z Jones, B. D., Baumgartner, F. R., Theriault, S. M., Epp, D. A., Lee, C., & Sullivan, M. E. (2023). Policy agendas project: Codebook. https://www.comparativeagendas.net/ Qadir, A., & Syväterä, J. (2021). The moral authority of science: Evidence from parliamentary debates in seven countries. European Journal of Cultural and Political Sociology, 8(3), 265–293. https://doi.org/10.1080/23254823.2021.1885461