Institute for International Economic Studies

Big news 🚨 Newly recruited Associate Professor (and IIES alumnus) Karl Harmenberg is awarded the Vetenskapsrådet / Swedish Research Council prestigious recruitment grant (only one at Stockholm University this year!) and returns to the IIES to tackle a big question: why recessions happen —and how to stop them.

https://www.su.se/english/divisions/institute-for-international-economic-studies/news/articles/2026-06-23-iies-researcher-awarded-prestigious-recruitment-grant-from-the-swedish-research-council

Congratulations to Juan Llavador Peralt on successfully defending his thesis “Firm Granularity, Growth, and Inflation Persistence: Essays in Macroeconomics”.

His research shows how dominant firms can slow growth—and why inflation persists longer than expected.

Thanks also to opponent Miguel León-Ledesma at University of Exeter Business School for a thorough discussion.

Next up for Juan: Banco de Portugal https://www.su.se/english/divisions/institute-for-international-economic-studies/news/articles/2026-06-12-successful-thesis-defense-for-juan-llavador-peralt

Big congratulations to Jonatan Riberth on defending his thesis “Essays on Healthcare Demand and Long-run Inequality"!

His research shows how personal experiences shape healthcare choices, and how inequality can persist across generations.

Next up: PostDoc for one year at Research Institute of Industrial Economics (working on a project with Petra Persson and Maya Rossin-Slater at Stanford University). He will then continue as a PostDoc at the Stockholm School of Economics.

A warm thank you to Martin Nybom from Uppsala University for providing a thorough and insightful discussion.

https://www.su.se/english/divisions/institute-for-international-economic-studies/news/articles/2026-06-11-jonatan-riberth-successfully-defends-his-thesis

What a milestone! Congratulations to Mattias Folkestad on defending his thesis, “Power and Politics: Essays in Applied Microeconomics”!

His work shows how institutions shape participation, efficiency and inequality — from female role models to green policy and education.

A warm thanks to opponent Olle Folke at Uppsala University for a stimulating discussion.

Next stop for Mattias: University of Gothenburg as Wallander Postdoc!

https://www.su.se/english/divisions/institute-for-international-economic-studies/news/articles/2026-06-10-successful-thesis-defense-for-mattias-folkestad

Huge congratulations to Thore Petersen on defending his thesis “Frictions and Flexibility in Production: Essays in Energy Economics”!
His research shows industry can decarbonize faster and at lower cost than we thought.
Many thanks to opponent and IIES alumnus Conny Olovsson at Sveriges riksbank for a thorough and engaging discussion!

https://www.su.se/english/divisions/institute-for-international-economic-studies/news/articles/2026-06-09-thore-petersen-successfully-defends-his-thesis

Båda sidor missar poängen i forskarbråket, skriver John Hassler Tessa Bold och Per Krusell vid det nystartade Assar Lindbeck centrum i Dagens Nyheter. Politik handlar inte bara om fakta utan även värderingar.

DN Debatt. ”Både sidor har fel när forskare och politiker träter” DN Debatt. John Hassler, Tessa Bold och Per Krusell: Därför räcker inte fakta för politiska beslut – så bör forskare, politiker och medier tänka.

Congratulations to Jinci Liu on successfully defending her doctoral thesis “Managers, Workers, and Teams: Essays in Organizational and Labor Economics”!
Her work sheds light on how feedback and workplace dynamics shape team performance and productivity.
Jinci will join National University of Singapore as Assistant Professor (after a 2-year postdoc). We look forward to following her next steps!
A warm thank you to Ricardo Perez-Truglia at UCLA Anderson School of Management for a lively and insightful discussion as opponent.
More information:
https://www.su.se/english/divisions/institute-for-international-economic-studies/news/articles/2026-06-08-successful-thesis-defense-for-jinci-liu

Join us in congratulating Tiago Bernardino on successfully defending his thesis "Consumption, Prices, and Policy: Essays in Macroeconomics and Public Economics". He will next join Universidade de Lisboa as Assistant Professor.
A warm thank you to our opponent Erik Hurst from University of Chicago Booth School of Business.
Read more: https://www.su.se/english/divisions/institute-for-international-economic-studies/news/articles/2026-06-05-tiago-bernardino-successfully-defends-his-thesis

Can big firms slow down growth, and keep inflation high?
In his thesis, IIES graduate student Juan Llavador Peralt highlights how the behavior of individual firms (especially large ones) can shape both productivity and inflation.

Key insights:

➡️ Market concentration can reduce growth
When a few firms dominate an industry, resources are less likely to flow to the most productive firms.

+10 percentage points in concentration → −3 percentage points in productivity growth

In more distorted markets, the decline can reach −13 percentage points

High concentration can create a “granular drag” on growth.

➡️ A few firms can shape entire industries
Even small differences in firm productivity can lead to long-lasting differences across sectors.

Large firms have outsized influence, meaning market structure alone can help explain why some industries grow faster than others.

➡️ Inflation persistence has firm-level roots
Why does inflation linger after a shock?

Because firms face costs of changing prices, they adjust at different times. Some react quickly, others delay, creating gradual, persistent inflation dynamics.

Importantly, this persistence emerges naturally from firms’ behavior, not from artificial assumptions in economic models.

The Takeaway:
Macroeconomic outcomes (like growth and inflation)are deeply shaped by what happens inside firms.

Understanding market structure and firm behavior is key for designing policies that support both productivity and price stability.

Juan will defend his thesis “Firm Granularity, Growth, and Inflation Persistence: Essays in Macroeconomics” on June 12.

https://www.su.se/english/divisions/institute-for-international-economic-studies/news/articles/2026-06-02-can-big-firms-slow-down-economic-growth

Why do people hesitate to vaccinate and how is inequality reproduced across generations?

In his thesis, IIES graduate student Jonatan Riberth highlights the powerful role of personal experiences in shaping health decisions, including vaccine hesitancy. In separate chapters, he examines how family background and historical wealth shocks shape inequality across generations.

Key insights:

➡️ Personal experiences strongly influence health choices

Individuals who experienced rare adverse events (such as narcolepsy after the 2009 swine flu vaccine) were much less likely to take COVID‑19 vaccines.

Health decisions are shaped not just by information, but by lived experience.

➡️ Perceptions of side effects can be misleading

People who experienced health issues shortly after vaccination, even when unrelated, were more likely to stop getting further doses

Timing of the health issue plays a key role, suggesting that misattribution of side effects is an important driver of vaccine hesitancy.

➡️ Wealth inequality can persist for centuries

A historic redistribution of wealth in Sweden in 1680 still affects descendants today.

Families that lost assets remain less wealthy up to five generations later, with little impact on education or social status.

➡️ Family matters rather than influences from the immigrant group

Differences between immigrant groups are often attributed to “ethnic capital”— the norms and expectations associated with a family’s country-of-origin group.

The thesis shows that much of what looks like an immigrant-group effect is better understood as extended family background.

The takeaway:

Health decisions are shaped not only by information, but also by how people interpret their own experiences. Inequality is deeply tied to family background, with advantages and disadvantages persisting across generations.

Jonatan will defend his thesis “Essays on Healthcare Demand and Long-run Inequality” on June 11.

https://www.su.se/english/divisions/institute-for-international-economic-studies/news/articles/2026-06-01-why-do-healthcare-choices-vary-and-why-do-inequalities-endure-across-generations