What comes after a PhD? Our alumnus, Rastislav Rehák, reflects on his postdoctoral journey at the Max Planck Institute for Research on Collective Goods and the University of Cologne, where he explores new directions in behavioral and environmental economics, as well as the passion that keeps him balanced outside of academia.

Life as a Post-doc

You’ve been in your postdoc for about a year and a half now. What has this stage of your career been like so far?

It’s been amazing! A postdoc is a curious mix of freedom and pressure—the freedom to explore new ideas, and the pressure of expectations and proving yourself.

How does your postdoc research build upon or differ from your PhD work?

One line of my research continues directly from my PhD, still primarily focused on theory and information. The other takes me into new territory: experiments and climate topics. Naturally, I’m also working on building bridges between the two.

What skills or experiences are you hoping to gain during your postdoc that will help your future career?

I hope to build on the infrastructure and expertise of those around me, especially in experimental work.

From Cognitive Limits to Climate Action

You focus on information economics and behavioral economics. Could you share your research findings in this field so far?

I’ve been drawn to the cognitive side of behavioral economics.

Take cognitive uncertainty: it’s a popular concept, but we still don’t fully understand what it reflects. Is the uncertainty people report the same as the uncertainty they actually feel when deciding? Not necessarily. My theory suggests the two can diverge in fast decisions—but in slower ones, they should align.

In another project, we focus on a neglected part of hiring: the behind-the-scenes chatter within a team. Do HR assistants talk about candidates differently depending on their gender or nationality? It turns out they do—at least in our representative sample acting as assistants in a controlled online experiment. It’s a subtle but important pattern, one that deserves closer study in real hiring situations.

Finally, imagine an advisor writing a report to guide a CEO’s investment decision. How should she group the possible project outcomes in her report? We develop a simple procedure to answer this for different kinds of disagreements. For example, if both agree that more profitable projects are better but differ in their risk attitudes, the optimal strategy can be surprisingly minimal—sometimes just revealing whether the project is not a disaster or whether it’s risky.

You’ve recently been working on linking morality and pro-environmental behavior. What drew you to environmental economics, and what questions are you trying to answer in this field?

I’ve long been curious about this area, but discussions with my current supervisor and collaborator, Axel Ockenfels, inspired me to dive in. In one experiment, we test the consequentialism of voluntary climate action—in other words, does it matter to people how their climate sacrifices are used? Surprisingly, the answer is often no. In follow-up studies, we aim to uncover the roots of this non-consequentialism, study how green narratives evolve, and ultimately design behaviorally and politically feasible institutions to foster climate cooperation, protect the planet, and, of course, beat Thanos.

Beyond Research

Let’s switch to something more personal. You enjoy long-distance running — are we talking marathons, or even ultra-marathons? Do you have any personal goals in your running journey?

I mostly enjoy marathons and ultra runs. For marathons, a sub-3-hour finish keeps me motivated. Ultras are more about the experience—the nature, the effort, the thrill—rather than a specific goal. My ambition is simply to be fit enough to enjoy running in the mountains for 15 hours. That said, these are long-term goals; right now, my training and shape are much more modest.

How do you stay connected to the CERGE-EI community, and what does the alumni network mean to you?

I’m always glad to connect with fellow CERGE-EI alumni. There are a few in my part of western Germany I’ve met up with, and it’s always reassuring to know that wherever you go, there are interesting people you can connect with through our shared CERGE-EI experience.