Paper: arxiv.org/abs/2103.10145
with Ludwig Dierks, Nils Olberg, Sven Seuken, Vince Slaugh

Empirically, a Florida agency that switched to caseworker-driven search saw a 3-year adoption probability 44.9% above a statewide benchmark, and a statistically significant 54% higher adoption hazard rate. Theory + computation + data, pointing toward better policy for children in foster care.3/4

Key theoretical finding: the caseworker-driven search can Pareto dominate every family-driven equilibrium, but not the other way around. When families are sufficiently impatient, caseworker-driven search is better for all children. Numerical results reinforce this across a wide parameter range.2/4

New draft of our paper: Over 70,000 US children are waiting for adoptive placements. We compare family-driven search (families respond to announcements) with caseworker-driven search (caseworkers proactively contact recommended families) using game theory, numerical analysis, and real-world data.1/4

The framework extends beyond blood to other multi-unit exchange settings with compatibility-based preferences.
Paper: papers.ssrn.com/sol3/papers....

These mechanisms are incentive compatible for donor revelation. A subclass — priority mechanisms — also ensures incentive compatibility for preference revelation. The theory builds on L♮-convexity from discrete convex analysis, new to the matching market design literature.

Current practice, first-come, first-served with rigid exchange rates, limits exchange among patients, causing inefficiency.
We introduce feasible menus, enabling flexible, endogenous exchange rates, and propose mechanisms to accommodate efficiency, fairness, and blood safety.

New revision of our paper w/ Xiang Han & Onur Kesten: "Flexible Multi-unit Exchange: Theory and An Application to Blood Allocation with Replacement Donors"
In 55 countries, volunteer donations meet <22% of blood demand. We improve how replacement donor programs allocate blood.

I did not anticipate this level of success, a program that completed in 3 years more exchanges than all conducted in the world combined in the previous 20 years. Most congratulations go to our partners in Malatya Inonu University.
@tayfunsonmez.bsky.social

The BBS-Liver Exchange System today completed its 300th transplant in Malatya, Türkiye, with 102 of them completed this year. Breakdowns of all transplants, categorized by exchange sizes and the type of pairs involved, are provided below. When we launched this program in 2022.

Prof Sezai Yılmaz's interview in Turkey related to the BBS-liver paired exchange program that Tayfun Sönmez and I founded with him and their other liver transplant achievements in Malatya, Turkey by their amazing team (use google translate)

ankahaber.net/haber/detay/...

Great article regarding Prof. Sezai Yilmaz, his great success in building a world-leading transplant center in Malatya, and the founding of our liver exchange system (Google Translate works reasonably well)

www.fortuneturkey.com/malatyayi-du...

@tayfunsonmez.bsky.social

Opinion | A Fact About the Floods the Government Doesn’t Seem Eager to Discuss

Elon Musk likened the government to the DMV; this is an incorrect and horrendous analogy. Another reminder:

www.nytimes.com/2025/07/09/o...

Musk's DMV = government analogy is so wrong at so many levels, especially in regulation and solving the public goods provision problem in research funding and infrastructure building. DMV analogy can work if police, traffic law provision and DOT become part of DMV. Then decide how to optimize it.

Nation Can't Believe It On Harvard's Side

One my favorite college professors, Joe Nye, passed very recently. He developed the concept of soft power in international relations.

Two of the strongest sources of US soft power were international aid and higher ed. The Republican administration has utterly destroyed both. Ask yourself why.

This is the stuff of authoritarian regimes. There isn't even the pretense that this is anything but persecution, unbound by law.

This is bleak reading

Why Turkey’s democratic future matters for the world My arrest in the government’s attempt to crush dissent shows how important the stability of my country is

From the mayor of Istanbul to the world, opinion essay on FT:

on.ft.com/4jxJrrj Why Turkey’s democratic future matters for the world

If you are not already following @seanmcarroll.bsky.social's Mindscape, probably the best Science and Philosophy podcast out there, you are definitely missing big time. After so many years of following, he deserves a shoutout. At these trying times, the best refuge.

I certainly agree with all points. Some are good for Europe clearly. But fur the US, the scary part is that this is a tipping point problem. Even if the wave turns back it will take generations to build normalcy with the allies. Brexit is a living example.

75% of US scientists who answered Nature poll consider leaving More than 1,600 readers answered our poll; many said they were looking for jobs in Europe and Canada.

Is the US going to become the science backwater it once was? The current administration's love of the 19th Century certainly points in that direction.
www.nature.com/articles/d41...

From the europe community on Reddit: 2.2 Million Gathered in İstanbul for Justice and Freedom of İmamoğlu Explore this post and more from the europe community

2.2 million people gathered to protest the recent arrest of Istanbul Mayor Ekrem Imamoglu, the main rival of Erdogan in the next presidential election.

It feels like Adam Smith never
wrote either "Theory of Moral Sentiment" or "Wealth of Nations" or even a pin factory was never opened. At least there will be many poli sci and econ PhD theses written in the next decade due to this bonanza.

Thank you, Al, for promoting our collaborators' work. You can more learn about the background of how we initiated the Liver Paired Exchange Program in Malatya in Section 12.3 of the manuscript of @tayfunsonmez.bsky.social

arxiv.org/pdf/2401.003...

Partial text of Justin Trudeau comments on Trump tariffs.

"We have fought and died alongside you....During your darkest hours...we were always there. Standing with you, grieving with you, the American people.” I’ve had my differences with Justin Trudeau, for sure, but he rose to the occasion here.

Working Group Report: Market Design

NBER Market Design Working Group Report, talking about many exciting recent papers in all areas of market design/design of economic mechanisms. www.nber.org/reporter/202...

papers.ssrn.com/sol3/papers....

Using French data, we demonstrate that our mechanism reduces the teacher experience gap across regions more effectively than benchmarks, including the current mechanism, while
providing higher average welfare for teachers.