Prof. Dr. André Casajus

Beauty is truth, truth beauty.

(John Keats)

After studies in Economics and Business Administration in Berlin, Frankfurt (Oder), and Leipzig and Mathematics in Hagen, I worked as an Interim Chairholder for Mathematical Economics at the Center for Mathematical Economics (IMW) of the University of Bielefeld for two years. In 2013, I joined HHL as a Research Associate and Senior Research Fellow at the Chair of Economics and Information Systems. From 2015 to 2017, I was fully funded by the German Research Foundation (DFG) as a Research Professor at HHL on the project “Solidarity and performance-relatedness in cooperative game theory”. Since 2018 and until 2020, again funded by the DFG, I work on the new project “Cooperative games, replicator dynamics, and stability”.

My research focus is on Cooperative Game Theory, which – cum grano salis – has two major themes. First, it analyzes the efficient and stable allocation of cooperation partners. And second, it is concerned with the fair and stable distribution of gains from cooperation in a wide sense. My work contributes to the second theme. Broadly speaking, I explore distribution rules, their properties, and the interplay of both. This helps us to convince people to apply one or another rule and to decide in which situation to apply which of the rules.

Most of what I’m doing is very technical with seemingly little practical relevance. For many weeks and even months, I sometimes think about an intricate proof of just one game theoretical conjecture, where it is not clear at all whether it holds true or not. Besides good trust in my intuitions, I often have the feeling that a particular result is so beautiful that is must be true. And in the end, the chain of reasoning that establishes its truth appears to be beautiful too – beauty is truth, truth beauty. That’s what keeps me going. The perhaps best example of such a result and its proof can be found in my recent paper “Symmetry, mutual dependence, and the weighted Shapley values”, published in the Journal of Economic Theory (178, 2018, 105-123).
Regularly, I act as a reviewer for scientific journals as for example Econometrica, the American Economic Review, the European Journal of Operational Research, Games and Economic Behavior, the International Journal of Game Theory, the Journal of Economic Theory, the Journal of Mathematical Economics, and Theoretical Economics and also for the German Research Foundation (DFG). In 2022, I will be the local organizer of the annual European Meeting on Game Theory hosted by HHL this time, which usually attracts about 150 researchers not only from Europe but also from around world.

Publications