Max R. P. Grossmann

Research

Edward Moran's 'Unveiling of the Statue of Liberty Enlightening the World' (1886): The painting captures the festive unveiling of the Statue of Liberty, with the statue centered against a cloudy sky, surrounded by smoke from salutes and a vivid flotilla of flag-adorned boats carrying onlookers.

⤵ Research statement ⤵ Job Market Paper

Find me on Google Scholar, ORCID and Semantic Scholar.

Research interests

I use experiments and surveys to study the following areas:

  • Political economy
    1. Behavioral foundations
    2. Paternalism, economics of freedom
    3. Philosophy, politics and economics
  • Behavioral and experimental economics
    1. Software for experiments
    2. Advanced experimental and computational methods

Publications in peer-reviewed journals

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. Published version

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.

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, 70(3):1343-1356. Published version

Selected work-in-progress

Knowledge and Freedom: Evidence on the Relationship Between Information and Paternalism

Job Market Paper · Working paper · Replication package

When is autonomy granted to a decision-maker based on their knowledge, and if no autonomy is granted, what form will the intervention take? A parsimonious theory shows how policymakers can exploit decision-maker mistakes and use them as a justification for intervention. In two experiments, policymakers (“Choice Architects”) can intervene in a choice faced by a decision-maker. We vary the amount of knowledge decision-makers possess about the choice. Full decision-maker knowledge causes more than a 60\% reduction in intervention rates. Beliefs have a small, robust correlation with interventions on the intensive margin. Choice Architects disproportionately prefer to have decision-makers make informed decisions. Interveners are less likely to provide information. As theory predicts, the same applies to Choice Architects who believe that decision-maker mistakes align with their own preference. When Choice Architects are informed about the decision-maker’s preference, this information is used to determine the imposed option. However, Choice Architects employ their own preference to a similar extent. A riskless option is causally more likely to be imposed, being correlated with but conceptually distinct from Choice Architects' own preference. This is a qualification to what has been termed “projective paternalism.”

Paternalism and Deliberation: An Experiment on Making Formal Rules

Working paper · Preregistration · Replication package

This paper studies the relationship between soft and hard paternalism by examining two kinds of restriction: a waiting period and a hard limit (cap) on risk-seeking behavior. Mandatory waiting periods have been instituted for medical procedures, gun purchases and other high-stakes decisions. Are these policies substitutes for hard restrictions, and are delayed decisions more respected? In an experiment, decision-makers are informed about an impending high-stakes decision. Treatments define when the decision is made: on the spot or after one day, and whether the initial decision can be revised. In a general population survey experiment, another class of subjects (Choice Architects) is granted the opportunity to make rules for decision-makers. Given a decision's temporal structure, Choice Architects can decide on a cap to the decision-maker's risk taking. In another treatment, Choice Architects can implement a mandatory waiting period in addition to the cap. This allows us to study the substitutional relationship between waiting periods and paternalistic action and the effect of deliberation on the autonomy afforded to the decision-maker. Our highly powered experiment reveals that exogenous deliberation has no effect on the cap. Moreover, endogenously prescribed waiting periods represent add-on restrictions that do not substitute for the cap. Choice Architects believe that, with time, the average decision-maker will take less risk and---because of the distribution of Choice Architects' bliss points---come closer to Choice Architects' subjective ideal choice. These findings highlight the complementarity of policy tools in targeting various parts of a distribution of decision-makers.

Integrating Machine Behavior into Human Subject Experiments (with Engel, C. & Ockenfels, A.)

Revise & resubmit at Experimental Economics · Working paper · GitHub

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 web experiments with human subjects. Our toolkit is freely available at github.com/mrpg/ego. To illustrate, we run simple differently framed prisoner's dilemmas with interacting machines as well as with human-machine interaction.

Public Support for the German Heating Law: When Ideology Trumps Knowledge (with Dertwinkel-Kalt, M.)

Under review at Journal of Public Economics

When policies are unpopular, it is often claimed that this is due to poor communication and a lack of the transmission of facts in the public debates of these policies. We investigate this claim at the hand of a recent controversial policy in Germany, the so-called Heating Law. We conduct a survey experiment in which we experimentally vary participants' factual knowledge of the Law. We find that knowledge plays no role for participants' attitudes and reaction to the Law. Instead, a pre-existing pro-environmental policy preference and socio-demographic factors are significantly predictive of attitudes and behaviors. These results suggest public support for climate policy is more strongly anchored in ideological beliefs and values than in understanding of policy details. We also find evidence for motivated reasoning and false consensus bias. Our findings have implications for public administration and research on misinformation: communicating facts may be insufficient to resolve policy disagreements.

Paternalism in Data Sharing (with Ockenfels, A.)

The privacy paradox is concerned with an ostensible disconnect between stated and revealed preferences for data sharing. The existence of this paradox has recently been questioned on methodological grounds. We study an interpersonal privacy paradox that overcomes these challenges. We test the claim of hypocrisy directly: do people want more privacy for others than themselves? We conduct an experiment in which Choosers can state a Willingness-to-Accept (WTA) for the publication of data about themselves. Another group of subjects (Choice Architects) can intervene in the Chooser's decision by imposing minimum and/or maximum prices to prevent publication even beyond the WTA. All of these measures are revealed preferences in the economic sense and thus comparable. We find that 30 percent of Choice Architects set a minimum price, but only few set a maximum price. Choice Architects don’t merely impose their own WTA on Choosers: they grant Choosers some liberty to express their own preferences. We conclude that Choice Architects do not act hypocritically at all: they are not stricter towards Choosers than towards themselves. The own WTA of Choice Architects who set a minimum-price exceeds the WTA of non-interventionist Choice Architects. When we correlate the minimum price to interventionists’ own WTA, we find a strong relationship. We find that beliefs over WTAs are strongly and systematically biased. The frequency of low WTAs is underestimated, while that of high WTAs is overestimated. This study sheds light on privacy paternalism and adds to a growing body of work that contests the privacy paradox.

uproot (with Gerhardt, H.)

Project website

We introduce a new, advanced, and web-based experimental framework.

Other publications

Sophomore’s Dream: 1,000,000 digits

Computation (world record, 2017). Download (sig)

See here for further information. The previous world record computation (from 2013, also by me) can be downloaded here.