Guillaume Roger Interview

What initially drew you to economics?

​

Nothing, really. I stumbled into it. I was doing an undergraduate degree in business in Europe, and after working a bit, I decided I wanted to pursue finance at a deeper level. I thought I would do a PhD in finance, so I applied to the University of Melbourne. They told me I needed an undergraduate finance degree first before I could do a finance PhD. And I thought, absolutely not. I wasn’t going to start from scratch just to satisfy a formal requirement. So I looked for something close enough to finance that still satisfied my intellectual interests. Economics was the alternative. It was almost accidental. I didn’t “choose” economics in a romantic sense. It was a pragmatic decision that turned out to be the right one.

​

So what prompted you to become a professor of economics and get your PhD?

​

That happened in stages. First, I did a master’s in economics. During that program, I realized that I genuinely enjoyed the intellectual process — not just learning models, but asking questions about how systems work. It was far more stimulating than the work I was doing professionally at the time. My professors noticed that I was engaged and encouraged me to pursue a PhD. They specifically told me that if I wanted to do serious research, I should go to the United States. So I applied to PhD programs there.

Initially, I thought I would finish the PhD and then return to industry or consulting. I did not imagine an academic career. But during the PhD, I caught what I call “the academic bug.” I enjoyed the freedom to think deeply about questions without someone telling me what the answer should be. I realized I belonged in research and teaching. That is when the professor path became clear.

​

What got you interested in electricity markets and contract theory?

​

Contracts came first, and again, partly by accident. I did my doctorate at USC, and one of the leading scholars in contract theory ended up being my advisor. I did not choose him strategically — it just unfolded that way. But he was one of the giants in the field. His intellectual influence shaped how I think to this day.

Electricity came later, also by accident. I once wrote a small paper analyzing the electricity market in Sydney. I uploaded it to an academic repository. The dean of a business school came across it and believed electricity markets in Australia were poorly designed. He contacted me and offered me a position to research electricity markets. I thought: I know only slightly more than the average person here, but I can learn. So I accepted. One step ahead of the game was enough. That’s how that specialization started.

What makes a research question interesting for you?

First, it must be new. If the question has already been answered convincingly, I’m not interested. Novelty is necessary.

Second, it must be publishable. That sounds practical, but in academia, if research cannot be published, it effectively doesn’t exist. So I need to know that the question has a path toward a solid academic contribution.

Third — and this is something I appreciated more as I matured — it must matter in the real world. Economics can easily become abstract model-building for its own sake. I’m no longer interested in models that are elegant but irrelevant. A good research question connects theory to real institutions, real markets, or real policy problems.

​

What is your framework once you decide on a research question?

​

I work mainly in theory. So I start by translating the real-world problem into a formal model — often a game. I specify players, incentives, constraints, information. Then I look for equilibrium or optimal solutions within that abstract structure.

Once I find a theoretical solution, the next step is implementation: how do real institutions map onto that abstract solution? That’s where things like auctions, contracts, or regulatory mechanisms come in. The challenge is bridging the clean mathematical world with messy reality. That’s the intellectually satisfying part.

​

What mistakes do you see students making when approaching economics?

​

Many come with rigid preconceptions about what economics is — usually shaped by media or undergraduate textbooks. That limits their imagination. They think economics is only about inflation, GDP, or stock markets. But economics is really a toolkit for studying incentives, information, and decision-making in any system.

When students cling too tightly to pre-defined ideas of “important topics,” they miss opportunities to discover questions that genuinely interest them. I tell my students: forget what you think economics is. Take the courses, learn the tools, and let your curiosity guide you.

What qualities do graduate students have who end up doing meaningful work?

Curiosity is the most important. A deep desire to understand how things work — not to get grades, not to finish assignments, but genuine intellectual hunger.

Technical skill matters too. You need mathematics, statistics, analytical discipline. But I would take a slightly under-equipped student who is intensely curious over a technically perfect student who is lazy or disengaged. Skills can be taught. Curiosity is much harder to instill.

What assumption in your early work did you later discard?

Early on, I believed that elegant theory was enough — that if the math was beautiful, the work was valuable. Over time, I realized that elegance without relevance is sterile. Now I care much more about whether a model captures essential features of reality, even if the math becomes messier. That shift fundamentally changed how I choose research topics.

What is the most valuable skill you’ve gained over time?

A combination of persistence, systematic thinking, and intellectual rigor. Economics trains you to break complex problems into structured components. Over the years, I’ve become more methodical, more patient, and more disciplined in attacking problems. That mindset extends beyond research — it applies to decision-making in any domain.

What is your number one piece of advice for students wanting to pursue economics?

Strengthen your mathematics. Economics at a serious level is very close to applied mathematics. Analysis, optimization, probability, statistics — these are the foundations. Once you have that base, you can branch into game theory, econometrics, market design, or finance. Math keeps every door open.

What piece of research do you personally find most beautiful or influential?

Two classics. First, the Arrow-Debreu general equilibrium framework — a complete model of an entire economy reaching equilibrium. It’s the intellectual benchmark for modern economics.

Second, the work of John Nash. Three short papers, fewer than ten pages each, revolutionized economics and mathematics. Almost everything I do today is intellectually downstream of Nash’s ideas. These works are so fundamental that we don’t even cite them anymore — they’ve become part of the language of the field.