Kai Purnhagen is a commercial law scholar with broad interests in the regulation of risks, in particular in EU and WTO law and in private relationships. His work is characterised by an openness to implement findings from other disciplines into law, most notably behavioural, economic, and safety sciences. His early research focused on the increasing role of systematisation in the harmonisation of risk regulation in EU law, which led to the publication of the book Systematisation of EU Product Safety Regulation. He also co-led a project on European legal culture at the LMU in Munich and at Oxford University, funded by a Thyssen grant. It investigated the different cultural settings in global and European trade relationships, including different legislations and juridical cultures. He advocated for a dialectical approach for the development of a European culture, which understands diversity as integral part of a unified culture. This work led to the well-received book Towards a European Legal Culture, which was commented inter alia by Hugh Collins, Steven Weatherill, Eric Jayme, Ewoud Hondius, Kåre Lilleholt, Norbert Reich, Gerhard Dannemann, and Thomas Wilhelmsson.
More recently, Kai has worked broadly on various aspects of risk regulation in WTO, EU law and German law, with a focus on the implementation of findings from behavioural, economic and safety sciences into law and regulation. His works have appeared in prestigious journals such as the European Law Journal, The Journal of World Trade, Nature, Journal of Consumer Policy, the European Law Review and the Rabel Journal of Comparative and International Private Law. He is also (co-)editor of various prestigious outlets, most prominently of the forthcoming Oxford Encyclopedia on EU law and the Springer Science Series Studies in European Economic Law and Regulation. Kai was also Founding Associate Editor of the European Journal of Risk Regulation (Cambridge University Press).
His works regularly influence law-making and interpretation at various levels. Among others, his works were taken up by the European Commission in marketing law, the German government in energy and consumer law and the German Supreme Court in contract law. In this respect, he regularly serves as an expert to various governments and consulting agencies such as the Chinese government, the European Commission, the German government and the Austrian government.
He was responsible for the legal part of interdisciplinary projects such as the Nudging project with the German ministry for the environment (Anstossen nachhaltiger Konsummuster, 2014-2016), the ZaNexus project for several German ministries (2015-2017), and the PERSON network led by the University of Groningen (2015-now).
Kai has taught and researched at various institutions including the Ludwig-Maximilian University Munich, the University of Lucerne, the European University Institute, Wageningen University, the London School of Economics and Political Science, the University of Wisconsin-Madison, the Justus-Liebig-University Giessen, and the University of Amsterdam.