Hello and welcome to my website! I am a postdoctoral researcher at Bocconi working on economic theory.

You can reach me at justus.preusser@unibocconi.it.

You can find my CV here.

I will be on the 2026/27 job market.

Job market paper.

The Division of Surplus and the Burden of Proof (with Deniz Kattwinkel).

Abstract. A principal and an agent divide a surplus. Only the agent knows the surplus' true size and decides how much of it to reveal initially. Both parties can exert costly effort to conclusively prove the surplus' true size. The agent's liability is bounded by the revealed surplus. The principal is equipped with additional funds. The principal commits to their own effort and, contingent on who provided evidence, to a division of surplus. With this multitude of instruments, the principal simultaneously motivates the agent to reveal the surplus and to exert effort to share the burden of proof. In optimal mechanisms, the principal exhausts these instruments in a particular order. We develop a novel solution technique to fully characterize optimal mechanisms in this multi-instrumental problem. Our technique is based on locally reforming existing mechanisms and can be applied to related multi-instrumental problems.