Publications
Sanctions, sales, and stigma: Intermediary online firms' market role in sustaining trade (with Alexandra Avdeenko, Maximilian Kaiser, and Krisztina Kis-Katos)
Journal of International Economics, 159, 104197, 2026
Abstract: In the wake of Russia’s full-scale invasion of Ukraine in February 2022, online intermediaries enabled brands to retain a presence in the Russian market as many global companies—presumably or actually—withdrew due to legal and reputational concerns. This paper examines how sales by intermediaries responded to international sanctions. Using novel data on customer transactions of 95 global brands from 1761 web shops, we show that sales to Russia dropped significantly after the invasion, especially among shops from countries enacting export restrictions. This drop was substantial yet not absolute. Guided by a stylized conceptual framework, we explore which intermediary shops helped sustain sales to Russia, linking their actions to economic incentives and the brand-specific legal and reputational concerns. Overall, we demonstrate how market structure shapes shops’ compliance with sanctions and highlight how economic incentives undermine compliance.
Media Coverage: Frankfurter Allgemeine Zeitung, WirtschaftsWoche
Measuring the DUI mode of innovation efficiently: A short-scale approach (with Jörg Thomä and Kilian Bizer)
Journal of Evolutionary Economics, 36(24), 2026
Abstract: This paper advances the empirical measurement of the Doing–Using–Interacting (DUI) mode of innovation, based on the conceptual framework of Alhusen et al. (2021) and its survey-based operationalization of Reher et al. (2024b). Using data from German SMEs, we examine whether the three-dimensional structure of DUI learning theorized in the literature can be mirrored empirically. Exploratory factor analysis (EFA) confirms this latent structure by identifying three main learning processes: (1) DUI internal (learning-by-doing and internal interaction), (2) DUI user-driven (learning-by-using), and (3) DUI external (learning-by-external-interaction). However, some factor loadings are problematic, suggesting that not all of the original indicators are suitable for measuring the DUI mode of innovation. Secondly, building on the latent structure identified through EFA, short scales of various lengths are developed using Ant Colony Optimization (ACO) to address practical constraints in innovation surveys. This provides a starting point for the further development of DUI innovation indicators that are particularly suited to less R&D-intensive innovation contexts, such as small firms, low-tech sectors, and lagging regions, as well as corresponding short scales.
Solving the puzzle? An innovation mode perspective on lagging regions (with Tobias Hädrich and Jörg Thomä)
International Regional Science Review, 48(4), 2025
Abstract: The promotion of innovation-driven development in lagging regions is currently on the regional policy agenda, so a sound understanding of how learning and innovation can be successful under the conditions there is crucial. In this context, this paper demonstrates the potential of an innovation mode approach at the micro level of regional innovation systems. Based on a conceptual framework on the relationship between knowledge bases and innovation modes in the field of regional development, a systematic literature review is used to analyze whether this potential has already been exploited in previous innovation studies on lagging regions. The results show that some important steps have already been taken in this direction. However, the potential gains in terms of a better understanding of innovation in lagging regions have so far been limited. Against this background, the authors identify several avenues for future research.
Personality and regional innovativeness: An empirical analysis of German patent data (with Petrik Runst and Jörg Thomä)
Research Policy, 53(6), 105006, 2024
Abstract: This paper brings together the literature on regional variability in innovation activity with studies on the role of personality for regional innovativeness. Building on regionally aggregated levels of individual Big Five personality traits obtained from the German Socio-Economic Panel and the Big Five Project, we find that only extraversion has a positive effect on patenting in German regions. This effect is particularly strong in the case of lagging regions. We interpret this finding as an indication of the compensatory role of collaboration for the innovativeness of lagging regions characterized by low levels of business research and development (R&D) and a dominance of small and medium-sized enterprises (SMEs), which demonstrates the need for place-sensitive policies that consider different modes of innovation and emphasize interregional and intraregional learning.
Working Papers
Measuring drivers of innovation beyond R&D: The case of SMEs in lagging regions (with Petrik Runst, Jörg Thomä, and Kilian Bizer)
Abstract: This paper examines the role of learning by doing, using and interacting (DUI) in SME innovation, with a particular focus on lagging regions, thus combining two settings characterized by a comparatively limited role of formal R&D. To capture DUI beyond its common conceptualization as interaction with external actors, we operationalize and test a comprehensive set of indicators covering internal, user-driven, and external learning processes. Using original survey data and Lasso regression as a data-driven selection technique suited to a large set of potential predictors, we identify a broad range of DUI learning practices associated with SME innovation, extending well beyond external interaction. Firm-internal learning practices feature most prominently in our results. This pattern is even more pronounced in lagging regions, pointing to their potential role in enabling firms to cope with less favorable conditions in their regional innovation environment.
Work in Progress
Socialism and the gender innovation gap: Evidence from German separation and reunification (with Sandra Chamier-Gliszczynski and Petrik Runst)
Migration and Female Innovation: Evidence from East German Migrants (with Sandra Chamier-Gliszczynski)
Energy Shocks, Innovation, and Technological Change in Germany