Hannah Rajski

Photo: Uni Mannheim - Alexander Münch

Welcome! I am a doctoral candidate in Political Science at the Graduate School of Economic and Social Sciences in Mannheim. Based at the Mannheim Centre for European Social Research (MZES), I work within the DFG-funded project “Election Forecasts for the German Federal Election 2025” (Zweitstimme.org).

My research focuses on electoral behavior and election forecasting. In my dissertation, I investigate voters’ expectations about election outcomes, what drives accuracy in these expectations, and how they can be aggregated into citizen forecasts.

I hold an MA from the University of Konstanz, with a semester at the University of Essex, and a BA from Zeppelin University, with a semester abroad in Bergen.

I am co-initiator of FLINTA* Square, a network for women, lesbian, intersex, non-binary, trans, and agender social scientists in Mannheim, together with Antonia May, Lisa-Marie Müller, and Malena Ullrich. If you are based in Mannheim and would like to join, please get in touch.

news

Sep 17, 2026	I will be at EPOP in Liverpool.
Jul 19, 2026	We have kicked off the 2026 Summer School for Women* in Political Methodology in Mannheim!
Sep 24, 2025	I received the CDSS Young Scholar Award together with fellow CDSS doctoral students Lisa-Marie Müller and Malena Ullrich to build a network for women* social scientists in Mannheim.

selected publications

The Zweitstimme Forecast for the German Federal Election 2025: Coalition Majorities and Vacant Districts

Cornelius Erfort, Lukas F. Stoetzer, Thomas Gschwend, Elias Koch, Simon Munzert, and Hannah Rajski

PS: Political Science & Politics, Feb 2025

Abs DOI

This article forecasts the German Federal Election of 2025. We used our previous forecasting models to provide national-level forecasts for party-vote shares and district-level outcomes for candidate votes. We show that the combination of both models allowed us to calculate forecasts for both coalition majorities in Parliament and "vacant districts" under recent electoral reforms.
The Role of Vote Advice Application in Direct-Democratic Opinion Formation: An Experiment from Switzerland

Isabelle Stadelmann-Steffen, Hannah Rajski, and Sophie Ruprecht

Acta Politica, Oct 2023

Abs DOI

In an increasingly digitized world, vote advice applications (VAAs) seem to be effective in providing voters with personalized information about their own positions vis-à-vis parties’ positions and specific policies. Even though electoral research has increasingly paid attention to the role VAAs play in voter’s opinion formation, very few studies have examined VAAs in the context of direct-democratic decisions. This article fills this gap by providing new insights into how VAAs affect individual decision-making in popular votes theoretically and empirically. We use novel data from the referendum campaign on the 2017 new energy law in Switzerland: a VAA experiment carried out in the framework of a three-wave panel survey. In the third wave, which took place a week before the referendum, respondents were randomly assigned to a treatment group and a control group; only the former was shown the VAA and made to use it. The results indicate two main takeaways. First, that using a VAA has a tangible effect inasmuch as the share of undecided voters is smaller among the treatment than among the control group. Second, VAA usage can have both a persuasive effect (i.e., it can change vote intentions) and an intensifying effect (i.e., it can strengthen voters’ preexisting intentions).
An Election Forecasting Model for Subnational Elections

Lukas F. Stoetzer, Cornelius Erfort, Hannah Rajski, Thomas Gschwend, Simon Munzert, and Elias Koch

Electoral Studies, Jun 2025

Abs DOI

While election forecasts predominantly focus on national contests, many democratic elections take place at the subnational level. Subnational elections pose unique challenges for traditional fundamentals forecasting models due to less available polling data and idiosyncratic subnational politics. In this article, we present and evaluate the performance of Bayesian forecasting models for German state elections from 1990 to 2024. Our forecasts demonstrate high accuracy at lead times of two days, two weeks, and two months, and offer valuable ex-ante predictions for three state elections held in September 2024. These findings underscore the potential for applying election forecasting models effectively to subnational elections.