About me
I am a postdoctoral researcher at the Chair of Banking at Goethe University in Frankfurt. Previously, I was part of the RTG 2484 - Regional Disparities & Economic Policy and the chair of Urban, Regional and International Economics at TU Dortmund University. My research focuses on topics in financial intermediation, climate banking and finance.
I received my PhD from TU Dortmund University in 2025. Previously, I completed a B.Sc. and a M.Sc. in Economics at the University of Bonn and spend an Erasmus semester at the University College Cork in Ireland. I also gained work experience at a local bank and interned at two consultancy firms.
You can download my CV here and contact me at dornseifer[at]finance.uni-frankfurt.de.
Research
Social connectedness and foreign direct investment
with Oliver Rehbein
This paper shows that cross-country social networks can help to mitigate frictions in foreign direct investment (FDI). First, we document an economically important relationship between real-world social networks, measured through Facebook, and FDI. We exploit common genetic ancestors as a novel instrument to establish a plausible causal link. Next, we show that social connectedness is more important if countries are legally and culturally different and if institutional frictions in the destination country are high. Social connections also mitigate investment frictions arising from climate risk. The effect of macroeconomic uncertainty on FDI is also significantly reduced by social connections.
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Close by or closed by? Bank branches and the rise of fintech mortgages
Online mortgage providers have flourished over the last decade while banks have downsized branch networks. This paper shows that rising market shares of fintech lenders in the US residential mortgage market account for a significant share of the decrease in bank branches. On average the rise of fintechs can explain 45% of the overall losses of branches per county. The relationship is more pronounced in metro areas and among small banks and leads to lower local deposits. To strengthen identification, I exploit the timing of the surge in fintech penetration and an instrumental variable based on Facebook’s Social Connectedness Index to Wayne County, the headquarter location of Quicken Loans, the largest fintech lender.
Work in progress
Flooded friends - Peer effects in flood insurance decisions
Best paper award at the 2nd European Sustainable Finance PhD Workshop
This paper explores how peer effects influence homeowners' decisions to insure against elemental damages. Using Facebook friendship links to flooded areas, it finds that stronger social ties increase insurance purchases in non-flooded regions: A doubling of social ties leads to a 1.2% rise in policies covering elemental damages. It highlights the moderating role of regional climate policy attitudes and social capital, showing that bridging social capital attenuates whereas bonding social capital amplifies the effect. This study contributes to the understanding of how social capital and climate attitudes influence household responses to climate risks.
Work in progress
FDI inflows and social capital in Germany
Work in progress