Journal articles

Favoritism towards high-status clubs: Evidence from German soccer

with Eberhard Feess and Helge Müller

(The Journal of Law, Economics, and Organization, Volume 38, Issue 2, July 2022, Pages 422–478,

Biases in legal decision making are difficult to identify as type II errors (wrongful acquittals) are hardly observable and type I errors (wrongful convictions) are only observed for the subsample of subsequently exonerated convicts. Our data on the first German soccer league allows us to classify each referee decision accurately as correct, type I error or type II error. The potential bias we are interested in is favoritism towards clubs with higher long-term status, proxied by the ranking in the all-time table at the beginning of each session and by membership. Higher-status clubs benefit largely from fewer type II errors. By contrast, the actual strength of clubs has no impact on referee decisions. We find no difference in type I errors and suggest anticipation of the bias as a potential explanation for the difference. We investigate several mechanisms potentially underlying our results; including career concerns and social pressure.

 Full Paper (Open Access)

Media Coverage: F.A.Z. Focus Welt Stern

Working papers

Trust in politicians and the provision of public goods: Evidence from Germany

Trust in politicians can influence government turnover, economic and government performance as well as the demand side of policy-making – voters' preferences over policies. In this paper I study how a lack of trust in politicians influences the supply side – policy provision. Using data on 63,000 legislative documents, 75,000 individual roll-call voting decisions as well as survey evidence for more than 2,000 candidates in German federal elections between 2009 and 2021, I show that low political trust leads politicians to be less concerned with the provision of many types of public goods - most importantly climate protection. In order to establish causality of these results, I follow an instrumental variable approach. My instrument functions similar to a shift-share instrument and leverages variation in internal migration patterns and differential exposure to common state-level shocks to political trust. An analysis of the underlying mechanism suggests that the results are mostly driven by the selection of different politicians rather than pandering to voters' preferences.

Working paper 

Political (self-)selection and competition: Evidence from U.S. Congressional elections

How does competition affect the entry and selection of politicians? I study this question using data on  U.S. Congressional elections between years 1998-2014.  My identification strategy levies changes in electoral competition due to redistricting. Difference-in-differences estimates reveal a discrepancy between the electorally dominant and weak party. The average candidate in primary elections of the weak party is more experienced and more likely to descriptively represent their district following an increase in competition. The reverse holds in the strong party. Investigating underlying mechanisms, I find suggestive evidence that candidates respond to preferences of party members, which may matter more in competitive elections.

    Working paper     Online Appendix

DADIT: A Dataset for Demographic Classification of Italian Twitter Users and a Comparison of Prediction Methods

with Carlo Schwarz, Dirk Hovy, Mahyar Habibi and Lorenzo Lupo

(forthcoming at LREC-COLING 2024)

Social scientists increasingly use demographically stratified social media data to study the attitudes, beliefs, and behavior of the general public. To facilitate such analyses, we construct, validate, and release publicly the representative DADIT dataset of 30M tweets of 20k Italian Twitter users, along with their bios and profile pictures. We enrich the user data with high-quality labels for gender, age, and location. DADIT enables us to train and compare the performance of various state-of-the-art models for the prediction of the gender and age of social media users. In particular, we investigate if tweets contain valuable information for the task, since popular classifiers like M3 don't leverage them. Our best XLM-based classifier improves upon the commonly used competitor M3 by up to 53% F1. Especially for age prediction, classifiers profit from including tweets as features. We also confirm these findings on a German test set.

    Working paper

Work in progress

Don't Stay so Close to Me? Impact of Refugee Inflows on Voting Behavior and Social Media Discourse (joint with Olivier Marie and Renske Stans)

(Draft coming soon.)

We study the impact of the arrival of refugees on natives' attitudes and voting behavior in the Netherlands following the unexpected and large refugee inflow in 2015-2016. Using a difference-in-difference approach exploiting the opening of refugee reception centers and uniquely detailed voting data, we find a significant increase in anti-immigration voting in areas (very) near newly established reception centers, with this effect diminishing over time and distance. Using data on more than 100 million posts on the social network X (formerly Twitter), we document a short-lived surge in normative posts about refugees, paralleling the initial rise in anti-immigration votes. While average sentiment towards refugees remains stable, we find an increase in polarization in opinions. We note a rise in discussions related to religion (Islam) after refugee center openings. Finally, we combine election data with data from X and show that increased support for anti-immigration parties is driven by areas where crime and cultural issues are salient, rather than areas with actual high crime rates or large migrant populations.

Career concerns and Managerial Risk Taking: Evidence from the NFL (joint with Hannes Ullrich and Florian Schuett)

MENTALISM: Measuring, Tracking, and Analyzing Inequality using Social Media  (joint with Carlo Schwarz, Dirk Hovy, Mahyar Habibi and Lorenzo Lupo)