Al Roth in conversation with Paul Milgrom about Moral Economics at Kepler's, Today 7pm

 Paul Milgrom and I will chat about Moral Economics and market design. (However, NB, Kepler's charges admission...:(

 Book talk at Kepler's, Thursday May 21, 7pm: Moral Economics, by Al Roth in conversation with Paul Milgrom

Kepler's Books 1010 El Camino Real Menlo Park, CA, 94025 

 "Nobel Prize–⁠winning economist Alvin E. Roth reframes some of our fiercest moral debates as markets, offering a solution that protects the vulnerable while preserving people’s rights to pursue their own interests. 

"About Moral Economics
Some of the most intractable controversies in our society are, essentially, about which actions and transactions should be banned. Should women and couples be able to purchase contraception, access in vitro fertilization, and end pregnancy by obtaining an abortion? Should people be able to buy marijuana? What about fentanyl? Can someone be paid to donate blood plasma, or a kidney?

"Disagreements are fierce because arguments on both sides are often made in uncompromising moral or religious terms. But in Moral Economics, Nobel Prize–winning economist Alvin E. Roth asserts that we can make progress on these and other difficult topics if we view them as markets—tools to help decide who gets what—and understand how those markets can be finetuned to be more functional. Markets don’t have to allow everything or ban everything. Prudent market design can find a balance between preserving people’s rights to pursue their own interests and protecting the most vulnerable from harm.

"Combining Roth’s unparalleled expertise as market design pioneer with his incisive, witty accounts of complicated issues, Moral Economics offers a powerful and innovative new framework for resolving today’s hardest controversies.

"About the Speakers 

Alvin E. Roth is the Craig and Susan McCaw Professor of Economics at Stanford University and the George Gund Professor of Economics and Business Administration Emeritus at Harvard University. A pioneering expert in the field of market design, he was awarded the Nobel Prize in Economics in 2012. A member of the National Academy of Sciences and past president of the American Economic Association, he lives in Stanford, California.

Paul Milgrom is the Shirley R. and Leonard W. Ely, Jr. Professor of Humanities and Sciences in the Department of Economics at Stanford University. He was awarded the 2020 Nobel Memorial Prize in Economic Sciences. His books include Putting Auction Theory to Work (2004) and Economics, Organization, and Management (1992). He has also written dozens of articles on auction design, game theory, and macro- and microeconomics."

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Metro Silicon Valley covers the talk this way:

"Nobel Prize-winning economist Alvin E. Roth is not exactly light entertainment, but this does sound like the rare bookstore talk built to pull in people beyond the usual policy crowd. The book is Moral Economics, his new argument that some of our ugliest public fights make more sense when you stop treating them as pure morality plays and start looking at them as markets with consequences. With fellow Nobel winner Paul Milgrom joining him, this should be smart without getting bloodless, and probably sharper, funnier, and more contentious than the phrase market design first suggests." 

 

Neale Mahoney interviews me abut Moral Economics on Econ to Go

 Neale Mahoney interviews me on Econ to go (with a transcript of our half hour conversation).

 "Neale Mahoney: Markets are often treated like natural objects, things that simply exist. But economist Al Roth sees them differently. To him, markets are human inventions, systems we design, shape, and sometimes struggle to agree on. Because when money and morality collide, things can get complicated. Who should be allowed to buy and sell? What should they be allowed to transact? and what happens when people want to trade things that others find morally unacceptable.

Alvin Roth: I think that one of the things we need to do is experiment on what we're morally obliged to do and reflect on it in connection with what we're actually able to do. 

Neale Mahoney: I'm Neale Mahoney, Economist and Director of the Stanford Institute for Economic Policy Research. On this episode of "Econ To Go," I catch up with Stanford Economist and Nobel Laureate Al Roth over coffee on campus. We talk about what he calls moral economics, the study of markets where society struggles to agree on what should be bought and sold. From kidney exchange to commercial surrogacy, from prostitution laws to the surprising economics of matchmaking, Al shows us that markets don't just allocate goods. They also reflect our values. You've said that markets and marketplaces are human artifacts. They are not just features of the natural environment. Why is that a good starting place when we think about the study of economics?

Alvin Roth: Well, for a long time, economists sort of thought that markets were things that we just had to take as given. You know, we speak of economists thinking of people as price takers, but in fact, they also thought of us as market takers. There are these markets. But of course, markets are human artifacts. To a great extent they're collective human artifacts, but marketplaces are often artifacts of individual companies or designers, or small groups of participants who modify the marketplace to fit their needs over time, just in the way that Uber is a marketplace designed by the company Uber. But I think there's a good analogy, which is that languages are also human artifacts, and they're collective human artifacts. You and I can speak to each other in English because we both learned English in a conventional way, but there are lots of words in our English that weren't in the language 100 years ago, words like computer and internet and AI. So, we're constantly modifying the language to better suit our needs."

Here is the whole half hour interview on YouTube:

 

There's also a Stanford news story:

Sex, drugs & surrogacy: When morality and markets clash
Stanford’s Alvin Roth won the Nobel Prize for improving how markets work. In a new book, he introduces a new way of thinking about society’s most controversial transactions, from sex work to drugs to assisted dying.  byKrysten Crawford
 

WHO reports on the global growth of nicotine pouches

 The World Health Organization (WHO) has released a report written by Robert K. Jackler, Divya Ramamurthi and Cindy Chau (Stanford Research into the Impact of Tobacco Advertising), and Ranti Fayokun (Tobacco Free Initiative, Department of Health Determinants, Promotion and Prevention, WHO).

Exposing marketing tactics and strategies driving the global growth of nicotine pouches 

 

"Key messages of the report are:
• The global market for nicotine pouches is growing rapidly.
• Nicotine pouches can be highly addictive; furthermore, some have high concentrations of nicotine, and some increase the speed and intensity of nicotine delivery (e.g. “pearls technology”).
• Labelling of nicotine content is not standardized and can be confusing and misleading.
• Some nicotine pouch packaging mimics popular candy products and contain high nicotine levels. If they are ingested by children, they can pose a lethal risk.
• Nicotine pouches often contain various youth-appealing flavours (e.g. sweet, fruity, mint/menthol), such as Cherry Punch and Frosted Apple, and candy-like flavours (e.g. “bubble gum” and “gummy bears”), which are particularly attractive to children.
The flavours of numerous alcoholic drinks are also used, marketed as “After dark”.
• Nicotine pouches often promote high-intensity nicotine and flavours with slogans such as “nicotine like never before” and visual depictions of the user experiencing a cooling effect.

• Nicotine pouches are aggressively marketed and promoted to young people.
– They are heavily advertised on youth-frequented social and digital media platforms, including through influencers.
– They are frequently promoted with youthful themes, including fun times with friends, romance and sports.
– They are often promoted for “discreet” or stealthy use, making it difficult to detect by parents or teachers, and as a way of breaking the rules.
– Manufacturers of nicotine pouches commonly sponsor youth-oriented events, where nicotine pouches and branded merchandise are distributed by attractive, young “brand ambassadors”.
• Nicotine pouch advertisements often use the tobacco industry’s “playbook” for marketing conventional tobacco products, such as cigarettes, including:
– “lifestyle marketing” and “identity marketing”, the message sometimes portraying how a consumer wishes to be perceived by others;
– depictions of nicotine pouches as “modern” and “high-tech”; and
– portrayal of nicotine pouches as boosting energy when the user is tired and helping the user to relax when stressed. Marketers call this “elasticity of meaning”, depicting the product as something that works for everyone in any situation.
• Nicotine pouch manufacturers market and associate their brands with holidays (e.g. Christmas) and cultural symbols (e.g. patriotism) to evoke happy times and celebrations.
• Messaging in nicotine pouch advertisements can appear contradictory, expressing opposing views; however, this is carefully crafted and tailored to different target groups, such as:
– co-marketing of a nicotine pouch brand with promotion of a flagship cigarette (or other tobacco) brand, while also marketing of nicotine pouches and conveying anti-cigarette messaging (e.g. “goodbye smoke smell”).
• Nicotine pouches are marketed with unsubstantiated claims that they aid smoking cessation and/or in ways that undermine quit attempts.
• Nicotine pouches are often promoted as a product for “Anytime, Anywhere”, with images of places in which smoking is not allowed. This marketing tactic can encourage dual use, hinder cessation attempts and undermine regulations prohibiting smoking or use of other tobacco and related products in public places.
• There is insufficient national action, whereby nicotine pouches commonly fall through regulatory gaps and thus either un- or lightly regulated.
• WHO calls for a comprehensive approach to tobacco control, covering the full spectrum of tobacco and related products, including nicotine pouches, and closing regulatory loopholes. "

Kidneys and Moral Economics in the Financial Times

I spoke about economics with Keynes (Soumaya) in the FT:

Nobel laureate Al Roth and the economics of organ sales  
 "The economist Alvin Roth been talking about kidneys since at least 2003, noting time and again that kidneys are in short supply, waiting lists are growing longer, and people are dying as a result.
 

"So why is Roth — who appears on this week’s episode of the Economics Show podcast — still banging on about kidneys? Well, because all of those things are still getting worse."

Here is the podcast:

FT Podcast  The Economics Show with Soumaya Keynes. Should economics have fewer taboos? With Alvin Roth.   The Nobel laureate on the lines society draws around what can be bought and sold  

and here is the transcript:

Transcript: Should economics have fewer taboos? With Alvin Roth
Soumaya Keynes speaks to Alvin Roth, Nobel laureate and author of ‘Moral Economics’

"    Soumaya Keynes
So we always start this show with a silly question. So, on a scale of one to 10, how relaxed are you about marketisation? So 10, you’re extremely relaxed about having transactions in literally anything, and maybe five is the average person.

Alvin Roth
So I’m probably a 7.5, maybe 7.52."
 
 

 

College admissions is a game of strategy, on both sides (from early admissions to waitlists)

 More colleges are admitting more students from early admissions/early decision applications, and fewer students from their waitlists.

The  WSJ has those stories.

Starting from the end, waitlists:

 The Only Thing Harder Than Getting Into College Is Getting Off the Wait List.   College wait lists have ballooned to give schools options; ‘Why continue stringing me on?’ By Roshan Fernandez

 "The University of California, Berkeley had almost 6,500 students on its wait list last year. It ended up admitting none of them.

"The only thing harder than getting into college, it seems, is getting off the wait list. At some schools, the wait list is far more selective than the college’s overall acceptance rate. 

...

"For colleges, it’s harder than ever to predict who will enroll because students are applying to more schools. Colleges have always used wait lists to manage enrollment, but the lists have ballooned in recent years. It’s part of many colleges’ elaborate cat-and-mouse game to manage yield, or the share of admitted students who enroll. And wait lists have turned increasingly unruly, with fewer standard protocols than traditional admissions.

 

###########

And before the waitlists come the early applications: 

The College-Admissions Chess Game Is More Complicated Than Ever
Students have to submit final decisions Friday after a byzantine cycle
By   Roshan Fernandez
 

"Many schools are leaning in to early application windows, filling more of their classes through early rounds. At Tulane University in New Orleans, about two-thirds of admissions offers to the Class of 2030 were extended via nonbinding early action, a spokesperson said. The school has also offered early decision since 2016.

"At some schools, early-round acceptance rates are three to four times higher than the regular round, which is why many admissions consultants suggest applying early. Colleges say this reflects a higher-quality applicant pool. 

...

"The moves come on top of a long-practiced yield-protection tactic: rejecting or wait listing applicants who seem overqualified and therefore unlikely to enroll." 

 

Moral Economics: video of the AEI book event (you can listen to me read from the book)

 You can watch the AEI book event (and hear me read the first paragraph of the book, and chat about it for about 20 minutes) followed by discussion by Alex Tabarrok, Judd Kessler and Nick Gillespie, and Q&A, all introduced an moderated by Sally Satel.

Here’s a picture taken by Peter Jaworski  

And here we are on Youtube (this was originally a live stream):

https://www.youtube.com/live/-TL4nlCpZEc 

 

The Organ Donation Dilemma: Ethics, Economics, and Life-Saving Solutions: Debate at Hopkins, today

Today's debate at Hopkins aims to focus on the proposed End Kidney Deaths Act.

 The Organ Donation Dilemma: Ethics, Economics, and Life-Saving Solutions
May 15, 2026 09:00 AM 
 

"With organ shortages claiming thousands of lives annually, this session explores whether carefully designed market mechanisms can increase donation rates while maintaining ethical standards and preventing exploitation.

Panelists:
-    Alexander Capron, USC Law/Bioethics  https://gould.usc.edu/faculty/profile/alexander-capron/ 

-    (TBC) Gabriel Danovitch, UCLA David Geffen School of Medicine, https://www.uclahealth.org/providers/gabriel-danovitch 

-    Kimberly Krawiec, UVA Law, https://www.law.virginia.edu/faculty/profile/kdk4q/1181653 

-    Elaine Perlman, President, Coalition to Modify NOTA and Executive Director, Waitlist Zero https://elaineperlman.com/ 

Moderator: 
-    Mario Macis, Johns Hopkins Carey Business School and HBHI https://mariomacis.net/index.html 

 

End Kidney Deaths Act summary /sites/default/files/2026-05/The%20End%20Kidney%20Deaths%20Act%20Summary.pdf

 

The list of 50+ supportive organizations, the legislative text, the podcast with Kim and Elaine and the Niskanen Center's economic analysis of the End Kidney Deaths Act 

Moral Economics: A Book Event at the American Enterprise Institute, May 14 (You're invited, IRL or watch remotely)

Moral Economics: A Book Event  with Sally Satel
Thursday, May 14, 2026 | 4:30 PM to 6:00 PM ET
AEI, Auditorium | 1789 Massachusetts Ave. NW | Washington, DC 20036

You can RSVP at the above link.

Event Contact: Jillian Holley | Jillian.Holley@aei.org
Media: MediaServices@aei.org | 202.862.5829


Agenda
4:15 p.m.
Registration Opens

4:30 p.m.
Opening Remarks:
Sally Satel, Senior Fellow, American Enterprise Institute

4:40 p.m.
Presentation:
Alvin E. Roth, Professor, Stanford University

5:00 p.m.
Panel Discussion

Panelists:
Nick Gillespie, Editor at Large, Reason
Judd Kessler, Professor, Wharton School, University of Pennsylvania
Alex Tabarrok, Professor, George Mason University

Moderator:
Sally Satel, Senior Fellow, American Enterprise Institute

5:45 p.m.
Q&A

6:00 p.m.
Adjournment 

"What should the government ban, and why? Questions surrounding the legal status of prostitution, marijuana use, abortion, euthanasia, and more are typically answered in the language of morality or religion. In his new book, Moral Economics: From Prostitution to Organ Sales, What Controversial Transactions Reveal About How Markets Work, Nobel Memorial Prize in Economic Sciences winner Alvin E. Roth contends that we should judge policies by their consequences, not only by their intentions. A panel of economists and cultural commentators will address Dr. Roth’s arguments.

Submit questions to Jillian.Holley@AEI.org.
If you are unable to attend in person, a video livestream will be made available on this page.

Related Content

Moral Economics: From Prostitution to Organ Sales, What Controversial Transactions Reveal About How Markets Work
Alvin E. Roth | Basic Venture | May 12, 2026"

Moral Economics: A Book Event live video 

 

Moral Economics: three podcasts, with Lawrence Krauss, Yascha Mounk, Sean Carroll

Some of the podcasts I participated in have or will come out this week, to mark the official publication of Moral Economics in the U.S. Here are those I became aware of yesterday.  I suppose you could binge on them if you want (or sample them, or even buy the book and read it or listen to it yourself:)

Below, on YouTube is the podcast with Lawrence Krauss that was recast after being lost. (It's also on substack.)

  

 "Alvin Roth is a Nobel Prizewinning Economist whose work on designing markets has had real world impacts that may have saved thousands of lives around the world, while arousing strong emotions both for and against the programs he has helped put in place.  Clearly not one to shy away from controversy, he represents the best of what The Origins Project is trying to promote: applying science and reason to public policy.   In short, connecting science and culture!

"Roth’s new book, which is fantastic, and comes out the same day this podcast is released deals with issues that often raise the public’s ire, from legalizing prostitution, to assisted suicide, and finally to a rational market for kidney transplants..."

########

Here's my conversation with Yascha Mounk (there's also a transcript accompanying his podcast The Good Fight, at the link):

Al Roth on Why People Should Be Free to Sell Their Kidneys
Yascha Mounk and Al Roth discuss what we miss when we separate economics from human emotion. 

"In this week’s conversation, Yascha Mounk and Al Roth discuss the impact of moral disgust on solving economic problems, whether we should allow financial payments for organ donation, and what the rise of OnlyFans tells us about changing attitudes towards the self and economic transactions. 

#######

And here's my conversation with Sean Carroll on his Mindscape podcast (with transcript):

Alvin Roth on the Economics of Morally Contested Markets 

 

 

Moral Economics: How to buy a copy at a bookstore

 It's publication day for Moral Economics, so I think my involvement in bookselling has probably reached it's peak.  You can buy it IRL now, at American bookstores, and my English publisher notes that you can still pre-order it there at a discount from independent bookstores (see below).

 Here's a snapshot taken at a Barnes and Noble in New York City on publication day May 12.

Moral Economics: New and Notable at Barnes and Nobel

 And here's a message from my publisher in England, where the book will come out in real life only later this month.

"May Pre-Order Offer 2026

We’re delighted to include your forthcoming book in our May Pre-Order Offer, for a limited time, readers will be able to pre-order your book and save 20%. With this offer, we’re aiming to drive extra sales supporting indie bookshops ahead of publication day.

How to get involved
Please share a Bookshop.org link to your book between 13-17th May.

Pre-order a copy of my book from Bookshop.org between 13-17 May and save 20% with the code: PREORDER20 Every sale supports real independent bookshops across the UK!"

 

 

 

Felix Salmon, at Bloomberg, reviews Moral Economics

  Felix Salmon, at Bloomberg, reviews Moral Economics, which starting today is now sold in stores (at least in the U.S.):

An Economist’s Case for Selling a Kidney.  In a new book, Nobel laureate Alvin Roth argues that decriminalizing taboo markets can save lives.  

He tells this story from the book:

"Roth gave a talk in 2017 at the Organ Donation Congress in Geneva about one such chain that started in 2015. A woman from the Philippines, known in the literature as FW, was willing to give up one of her kidneys to save the life of her husband, FM. The two flew to the US, where FM received a kidney from an altruistic donor in Georgia, and FW’s kidney was transplanted into a man in Minnesota. A friend of the Minnesota man, who had been willing to give up one of her kidneys to save his life, instead gave one to a man in Washington, whose father-in-law gave a kidney to a woman in Georgia, and so on. By the end of the year there had been 11 successful transplants, and the chain was still continuing.

" After his talk, Roth was confronted by a Spanish doctor who was deeply concerned about the potentially problematic implications of the economic inequality between the Philippines and the US. Roth pointed out that without the transplant, the patient would surely have died. Replied the Spanish nephrologist: “He should be dead!” Spain’s National Transplant Organization later denounced Roth as an organ trafficker.

"Roth tells this story in his most recent book, Moral Economics (Basic Venture, May 12), which, at least in part, is an attempt to apply the empiricism of economics to domains that are often resistant to such analysis. The opposition to the 2015 kidney chain, for instance, comes from nephrologists who have no problem with chains but who draw the line at international chains, or at least chains linking poor and rich countries."

######

Much of the objection to cross-border kidney exchange appears to be fading, some of it was based on the idea that countries should be self-sufficient in transplants.

See earlier posts:

Friday, January 9, 2026  WHO Says Countries Should Be Self-Sufficient In (Unremunerated) Organs And Blood by Krawiec and Roth (now open source)

 

Friday, September 11, 2020  Global Kidney Exchange supported by the European Society of Transplantation's committee on Ethical, Legal, and Psychosocial Aspects of Transplantation .

Roth and Fisman at Cambridge Public Library, discussing Moral Economics: THIS Evening

 Alvin E. Roth at the Cambridge Public Library   Monday, May 11 at 6 pm 

 

 

presenting Moral Economics: From Prostitution to Organ Sales, What Controversial Transactions Reveal About How Markets Work

Harvard Book Store and the Cambridge Public Library welcome Alvin E. Roth—Nobel Prize–⁠winning economist, the Craig and Susan McCaw Professor of Economics at Stanford University, and the George Gund Professor of Economics and Business Administration Emeritus at Harvard University—for a discussion of his new book, Moral Economics: From Prostitution to Organ Sales, What Controversial Transactions Reveal About How Markets Work. He will be joined in conversation by Ray Fisman—who holds the Slater Family Chair in Behavioral Economics at Boston University.

Ticketing

RSVP for free to this event or choose the "Book-Included" ticket to reserve a copy of Moral Economics and pick it up at the event. Following the presentation will be a book signing.

Note: Books bundled with tickets may only be picked up at the venue the night of the event, and cannot be picked up in-store beforehand. Ticket holders who purchased a book-included ticket and are unable to attend the event will be able to pick up their book at Harvard Book Store up to 30 days following the event. This offer expires after 30 days. Please note we cannot guarantee signed copies will be available to ticket holders who do not attend the event.

About Moral Economics

A Nobel Prize–⁠winning economist shows us why we have to deal in trade-offs when we can’t agree on what’s right and what’s wrong.

Some of the most intractable controversies in our divided society are, at bottom, about what actions and transactions should be banned. Should women and couples be able to purchase contraception, access in vitro fertilization, and end pregnancy by obtaining an abortion? Should people be able to buy marijuana? What about fentanyl? Can someone be paid to donate blood plasma, or a kidney?

Disagreements are fierce because arguments on both sides are often made in uncompromising moral or religious terms. But in Moral Economics, Nobel Prize–winning economist Alvin E. Roth asserts that we can make progress on these and other difficult topics if we view them as markets—tools to help decide who gets what—and understand how those markets can be fine-tuned to be more functional. Markets don’t have to allow everything or ban everything. Prudent market design can find a balance between preserving people’s rights to pursue their own interests and protecting the most vulnerable from harm.

Combining Roth’s unparalleled expertise as market design pioneer with his incisive, witty accounts of complicated issues, Moral Economics offers a powerful and innovative new framework for resolving today’s hardest controversies.

Bios

Alvin E. Roth is the Craig and Susan McCaw Professor of Economics at Stanford University and the George Gund Professor of Economics and Business Administration Emeritus at Harvard University. A pioneering expert in the field of market design, he was awarded the Nobel Prize in Economics in 2012. A member of the National Academy of Sciences and past president of the American Economic Association, he lives in Stanford, California.

Ray Fisman holds the Slater Family Chair in Behavioral Economics at Boston University. His research focuses primarily on corruption, both in the U.S. and globally. It has appeared in leading economics journals including the American Economic Review, Journal of Political Economy, Quarterly Journal of Economics, and Review of Economic Studies, and has been widely covered in the popular press, in such outlets as the New York Times, Wall Street Journal, Financial Times, the Economist, and the Washington Post. His next book, on the economics of business social responsibility, will come out in 2027.

Masking Policy

Masks are encouraged but not required for this event.

Co-Sponsor

The Cambridge Public Library serves as a doorway to opportunity, self-development, and recreation for all its residents, and as a forum where they may share ideas, cultures, and resources among themselves and with people around the globe. Learn more at cambridgema.gov/cpl.

Perils of podcasting

 I had a stimulating 3 hour discussion with famed podcaster Lawrence Krauss a few days ago, about my forthcoming book Moral Economics.  Almost immediately after we concluded, it turned out that neither of us had recorded it. (We did a  shorter makeup later.)

 Here's his tweet on that:

Lawrence M. Krauss   @LKrauss1

Today my podcast worst nightmare happened.  

I did a 3 hour  @OriginsProject podcast with Nobel Laureate Alvin E. Roth on his wonderful new book, Moral Economics, that I thought was one of the best podcasts I have recorded. Except I forgot to hit record! Lost it all! With amazing grace and perseverence, he agreed to redo it 2 hours later. What resulted may have been even better. My colleague and friend @slsatel at AEI (who will do an event with him there May 14 ) told me he was a mensch. And boy was she right. I cannot believe his kindness. Thank you Al! And your book is truly inspiring. Hope to release the podcast next week. Watch it and then buy the book! Or buy the book and then watch it. :)

 

Markets, Morals and the Road Ahead: A Conversation with Dr. Vikas Shah about Moral Economics (on Thought Economics)

 Dr. Vikas Shah has published a post on his site Thought Economics, devoted to my imminently forthcoming book Moral Economics.  The long transcript combines a conversation we had together, interspersed with bits of the book itself, paraphrased to appear as part of the live conversation.

Markets, Morals and the Road Ahead: A Conversation with Nobel Laureate Professor Alvin Roth· by Dr. Vikas Shah 

"Roth’s new book, Moral Economics: From Prostitution to Organ Sales, What Controversial Transactions Reveal About How Markets Work (Basic Venture, 2026), is a tour through what he calls repugnant transactions — exchanges that consenting parties want to make but that others believe should be forbidden, often on moral or religious grounds. The territory ranges from sex, surrogacy and adoption to alcohol, drugs, blood plasma, vaccine challenge trials, kidney transplants and medical aid in dying. Roth’s central argument is bracing in its calm: most contested markets cannot really be abolished, only relocated — driven underground, exported across borders, or left to operate informally and dangerously. The honest question is therefore not whether to permit such markets, but how to design and regulate them so that they command sufficient social support to work, and so that the costs and benefits fall in places we can defend. Markets, in his view, are tools to help decide who gets what; the work of moral economics is to keep asking, with evidence rather than absolutes, how those tools should be built. I spoke with him about the philosophical architecture of the book, the everyday paradoxes of repugnance, the lessons of kidney exchange, the controversies around vaccine challenge trials and assisted dying, and what new frontiers of moral contention the next generation of technologies — from CRISPR to artificial intelligence — will force us to confront."