G’day. I am a Research Fellow (Level B, continuing) in the Department of Economics at the University of Melbourne and the Lab Manager of the Experimental Economics Laboratory (E²MU).

My research in experimental and behavioral economics examines paternalism, the economics of freedom, and public support for policy. Using controlled laboratory experiments and large-scale surveys, I study how individuals make decisions about rules that constrain others’ choices. I also develop open-source software for the experimental research community, including uproot, a framework for behavioral experiments, and ego, a toolkit for integrating machine behavior into human participant experiments.

I hold a doctorate in economics from the University of Cologne, where I was supervised by Axel Ockenfels and Frederik Schwerter. I also completed a master’s degree in economics and a bachelor’s degree in business administration at the University of Cologne, and studied abroad at the University of Texas at Dallas.

Prior to joining the University of Melbourne, I managed the Cologne Laboratory for Economic Research for over five years and was an Oskar Morgenstern Fellow at the Mercatus Center at George Mason University.

Publications in peer-reviewed journals

1. Integrating Machine Behavior into Human Subject Experiments: A User-friendly Toolkit and an Application to Framed Prisoner’s Dilemmas (with Engel, C. & Ockenfels, A.)

   Experimental Economics (2026) · Journal version · GitHub · Interactive experiment builder · Abstract [−] Abstract [+] · Citation [−] Citation [+]

   Large Language Models (LLMs) have the potential to profoundly transform and enrich experimental economic research. We propose a new software framework, “alter_ego”, which makes it easy to design experiments between LLMs and to integrate LLMs into oTree-based experiments with human subjects. Our toolkit is freely available at github.com/mrpg/ego. To illustrate, we run differently framed prisoner's dilemmas with interacting machines as well as with human-machine interaction. Framing effects in machine-only treatments are strong and similar to those expected from previous human-only experiments, yet less pronounced and qualitatively different if machines interact with human participants.

   @article{ego,
       title = {{Integrating machine behavior into human subject experiments: a user-friendly toolkit and an application to framed prisoner's dilemmas}},
       author = {Engel, Christoph and Grossmann, Max R. P. and Ockenfels, Axel},
       journal = {Experimental Economics},
       year = {2026},
       pages = {1--16},
       doi = {10.1017/eec.2025.10038},
       keywords = {mrpg},
   }

2. Reproducibility in Management Science (by Fišar, M., Greiner, B., Huber, C., Katok, E., Ozkes, A. and the Management Science Reproducibility Collaboration [consortium co-authorship])

   Management Science (2023), 70(3):1343-1356 · Journal version · Citation [−] Citation [+]

   @article{fivsar2024reproducibility,
       title = {{Reproducibility in {\it Management Science}}},
       author = {Fi{\v{s}}ar, Milo{\v{s}} and Greiner, Ben and Huber, Christoph and Katok, Elena and Ozkes, Ali I and {Management Science Reproducibility Collaboration}},
       journal = {Management Science},
       year = {2024},
       volume = {70},
       number = {3},
       pages = {1343--1356},
       publisher = {Informs},
       doi = {10.1287/mnsc.2023.03556},
       keywords = {mrpg},
   }

3. z-Tree unleashed: A novel client-integrating architecture for conducting z-Tree experiments over the Internet (with Duch, M. L. & Lauer, T.)

   Journal of Behavioral and Economic Finance (2020) · Journal version · Abstract [−] Abstract [+] · Citation [−] Citation [+]

   We present z-Tree unleashed, a novel approach and set of scripts to aid the implementation of computerized behavioral experiments outside the laboratory. z-Tree unleashed enables subjects to join the experiment using a web portal that requires no software apart from a web browser. Experimenters are likewise enabled to administer their experiments from anywhere in the world. Except for z-Tree itself, z-Tree unleashed is entirely based on free and open-source software. In this paper we give a high-level overview of z-Tree unleashed’s features and benefits and its design. We also show how to set up the server and demonstrate the steps required for conducting an entire experiment. We subsequently explain how to leverage the security and routing features of a virtual private network with z-Tree unleashed, enabling servers to securely run behind routers.

   @article{zTu,
       title = {{{\it z-Tree unleashed}: A novel client-integrating architecture for conducting z-Tree experiments over the Internet}},
       author = {Duch, Matthias L. and Grossmann, Max R. P. and Lauer, Thomas},
       journal = {Journal of Behavioral and Experimental Finance},
       year = {2020},
       volume = {28},
       pages = {100400},
       publisher = {Elsevier},
       doi = {10.1016/j.jbef.2020.100400},
       url = {https://www.sciencedirect.com/science/article/pii/S2214635020303270},
       issn = {2214-6350},
       keywords = {mrpg},
   }

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