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Olof Ejermo

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olof.ejermo@ekh.lu.se
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My research interests are broadly within areas of innovation and entrepreneurship. I am interested in process of spillovers of knowledge in science, innovation and entrepreneurship, for instance studied through mobility and migration. Connected to this is an interest in academic-industry interaction. My strive in economic historic research is to understand the role and development of foundations for industrial and economic development and link this to the contemporary economy.

I study innovation and entrepreneurship from an innovation economics point of view. My research draws theoretically more from evolutionary path-dependent and non-optimizing thinking. On the other hand, my empirical toolbox has strongly been inspired by the developments in applied econometrics towards causal identification strategies (cf. The Prize in Economic Sciences 2021 – Prize announcement (nobelprize.org)). My research is also strongly based on the collection and honing of own large-scale data, visible through the collection of three sets of data: inventor data on individual level, publication data by academics and entrepreneurship data in economic history.

Some of the broad questions that my research aims to answer are: How does knowledge spread? How do individuals interact and affect other? And some of the channels I’m interested in concern migration, mobility, innovation programs, infrastructure, and trade. 



Related publications

    Working paper

    Ratio Working Paper No. 389: Parenthood and the Gender Gap in Academic Careers

    Ejermo, O., & Holmström, P.
    Download

    Publication year

    2026

    Published in

    Ratio Working Paper Series.

    Abstract

    Using population-wide data on Swedish university researchers and teachers, we identify the effects of parenthood on academic careers. Leveraging staggered event-study models that compare mothers and fathers around first birth, we document widening gender gaps in publication output, wage income, promotion, and PhD completion. These gaps arise across all scientific fields. We further document substantial gender differences prior to first birth and among never-parents, indicating that child-related penalties explain only part of the overall academic gender gap.

    Article (with peer review)

    Historical manufacturing census of Sweden: Data description and quality assessment

    Almås, I., Berger, T., Boppart, T., Burchardi, K., Ejermo, O., Eriksson, B., & ..
    Download

    Publication year

    2026

    Published in

    Historical Methods: A Journal of Quantitative and Interdisciplinary History, 2026.

    Abstract

    Article (with peer review)

    Innovation in Malmö after the Öresund bridge

    Ejermo, O., Hussinger, K., Kalash, B., & Schubert, T.

    Publication year

    2022

    Published in

    Journal of Regional Science, 62(1), 5-20.

    Abstract

    We analyze the effect of the Öresund Bridge, a combined railway and motorway bridge between Swedish Malmö and the Danish capital Copenhagen, on inventive activity in the region of Malmö. Applying difference-in-difference estimation on individual-level data, our findings suggest that the Öresund Bridge led to a significant increase in the number of patents per individual in the Malmö region as compared with the two other major regions in Sweden, Gothenburg, and Stockholm. We show that a key mechanism is the attraction of highly qualified workers to the Malmö region following the construction of the bridge.

    The article in total can be accessed here.

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