Few economists have done more to shape how scarce, life-changing resources are actually allocated in the modern world than Alvin E. Roth. The Craig and Susan McCaw Professor of Economics at Stanford, George Gund Professor of Economics and Business Administration Emeritus at Harvard, and a Senior Fellow at the Stanford Institute for Economic Policy Research, Roth shared the 2012 Nobel Memorial Prize in Economic Sciences with the late Lloyd Shapley for the theory of stable allocations and the practice of market design. Where most economists describe markets, Roth has spent his career building them — redesigning the National Resident Matching Program that places American doctors into hospital residencies, the centralised systems that match children to schools in cities such as Boston and New York, and, most consequentially, the algorithms behind kidney exchange, which now accounts for around thirty percent of living-donor kidney transplants performed in the United States and has saved many thousands of lives. He chronicles much of this work, and his abiding fascination with the moral edges of markets, on his long-running blog Market Design.
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.
Vikas Shah: You define markets as tools for deciding who gets what. But the moment the ‘what’ becomes children, kidneys, sex, blood or drugs, the conversation shifts. How should we see that distinction between an ordinary market and a morally contested one?
Alvin Roth: Well, you know, if it’s a question of who should get a salad, there’s not much moral contest about that. Most of our concerns are then just about the mechanism — should you get it at the supermarket or at a restaurant? But with moral contest, there’s a different sort of question being asked. There’s some question about whether you should have a salad at all.
Salads don’t have that problem, but all those other things you mentioned do. So a useful way to think about it is that morally contested markets have fans as well as foes. Repugnance, in the way I use the word, isn’t disgust. Disgust is a near-universal reaction that protects us from contamination — no restaurant offers you a beverage made from someone else’s saliva because no one would buy it. A repugnant transaction is different: people want to engage in it, and others — who often can’t even tell when it’s happening unless they’re told — think they shouldn’t be allowed to.
Alvin Roth: It’s not a brand new idea, either. Back in 1780, Jeremy Bentham used the word antipathy to describe the same impulse — what he called the principle by which we approve or disapprove of certain actions not because of their effect on the happiness of the people involved, but simply because we find ourselves disposed to approve or disapprove of them. A useful small-scale modern example is that it’s a felony in California to sell horsemeat for human consumption — not because horsemeat is unsafe, but because in 1998, sixty percent of California voters said they didn’t want it sold, even though many other Californians, from cultures where horsemeat is eaten with pleasure, would happily buy it. That’s the basic shape of a repugnant transaction in miniature: people want to engage in it, others want them not to, and you wouldn’t even know it was happening unless somebody told you. The question for an economist who designs markets is what to do with that disagreement — because pretending it isn’t there is not a serious option, and neither is pretending the underlying need will simply go away if we ban the transaction.
Vikas Shah: Do we generally underestimate the moral meaning people attach to markets? Your book puts something in plain sight that was almost hiding in plain sight.
Alvin Roth: I don’t know if we underestimate it. The internet seems like an outrage engine sometimes, so maybe some of us overestimate it and probably some of us underestimate it. But the question is, what’s the moral content of all the things we do in the world? Because economists and markets are really about just about everything, and of course there’s some moral content about which we can disagree.
What I’ve tried to do in the book is take that disagreement seriously rather than wave it away. People sometimes assume economists want to monetise the world and make every transaction look the same, but in fact most of what market design tries to do is figure out which markets need money and which work better without it. Marriage and dating are markets even when no money changes hands. Kidney exchange is a market without money. Blood donation is a market without money in most places. The moral content shows up partly in whether we use prices at all, and partly in the rules we layer around those prices when we do. Once you see that, you stop thinking of “the market” as a single thing with a single moral standing, and you start asking, of any particular market: what are the goals, who are we trying to protect, what tradeoffs are we prepared to make?
Vikas Shah: At the centre of the book is the concept of repugnant transactions — willing participants want to undertake them, others believe they should not be allowed. How should we discuss that, given you’re careful to point out it isn’t always wrong?
Alvin Roth: I think the whole idea of wrong is related to discussing things in moral terms. We’re accustomed to discussing morality and right and wrong. But we may not have to judge those things entirely in terms of their consequences — and yet it turns out that we can’t divorce our discussion entirely from consequences either. Often there are things we think are wrong. We wouldn’t like there to be any heroin in society, but there’s plenty of heroin. So our discussion about what to do about it has to not just concern our moral feelings about drug addiction and drugs, but our consequential feelings about how we feel about people in prisons, having overdose deaths, and the effect on society and on individuals and on communities. You can’t escape a discussion of consequences when you talk about the world.
That’s why I try to draw a distinction in the book between two kinds of opposition. There’s principled opposition that doesn’t depend on outcomes — for some people, certain things are simply wrong, full stop, and if a policy fails to prevent them that’s a problem with the policy, not a reason to reconsider the principle. And then there’s consequentialist opposition, where the harm we point to is the harm we expect to prevent. Most public debate slides between the two without noticing. If you and I disagree about heroin, we should at least be clear whether we’re disagreeing about the moral status of taking the drug, or the empirical question of how many people would become addicted under different regimes, or the further empirical question of how many addicts we are willing to let die rather than treat. Those are three very different debates, and they call for different kinds of evidence and different kinds of moral reasoning.
I first wrote about this in 2007 in a paper called Repugnance as a Constraint on Markets. One of the unintentional compliments the paper got was that people on both sides of the kidney-payment debate said, in effect, “You presented both sides fairly — but I could tell that you really agree with me.” I take that as a sign the paper was doing something useful, because if you’re describing your own side honestly it’s natural that the description will feel compelling to you. I’ve tried to keep my thumb off the scales in this book too. I do have personal opinions on many of these issues — and where I do, I’ll say so — but my goal is not to tell you what to think. It’s to help you think, with as much of the evidence as we have laid out as fairly as I can manage.
Vikas Shah: Are there cases where repugnance is morally wise rather than obstructive — beyond the obvious, like murder for hire?
Alvin Roth: Why accept the obvious? Many things are obvious to some people that aren’t obvious to the rest of us. People have strong moral intuitions. We would like there to be no murder, but still there are some murders. On the other hand, we sensibly put people in prison when we convict them of having committed murders, and that seems to keep the process about as much in control as we can manage. There’s not too much controversy about that, because we all condemn murder and think that murderers are criminals who should be put in jail.
We don’t feel that way about people who use drugs. We don’t feel that way about many, many other things. Not everyone is zero or one on any of these things — some of these things have lots of nuances. You’re sitting in Britain, which is, on the matter of surrogacy, midway between Western Europe and the United States. In much of Western Europe they ban surrogacy outright. In England you recognise parental rights in surrogacy but don’t allow surrogates to be paid. And in the United States we have commercial surrogacy throughout most states. You can view each of those things as moral, but of course it’s quite hard to effectively ban something in Europe that’s available legally in California.
That’s worth dwelling on for a moment, because it’s one of the patterns that recurs throughout the book. When repugnance attaches to something whose underlying need is real and unevenly distributed — surrogacy, abortion, assisted dying, kidney transplantation — the bans we put in place do not abolish the transaction. They mostly redistribute access to it. Wealthy people fly to California or Switzerland; poorer people don’t. So a ban that feels like a clean moral statement at home may, in practice, look much more like a way of saying: this option is available, but only if you can afford the airfare.
Vikas Shah: One of the most powerful ideas in the book is that banning a market can be the first step in designing the black market that replaces it. What have policymakers misunderstood about prohibition — and why do some bans work and others fail?
Alvin Roth: That’s why in the book I talk about heroin and hitmen. The prohibition on murder seems to be working pretty well, so we should keep it up; especially murder for hire — when we catch hitmen, we should lock them up for as long as we can. That’s a policy that seems to work and has a lot of social support.
On the other hand, we have a similar policy applied to drug dealers — addictive drug dealers, who we don’t approve of at all — but it’s not working there. Our prisons are full of both drug dealers and drug users, who are sometimes the same people. Communities are being destroyed and lots of people are dying of overdose. So we have two similar policies. One of them has enough social support to work well — we should keep it up. The other is causing many associated damages that we’re not controlling, and we should think about how to control them and how to regulate them. Taking a transaction we really hate, like selling heroin, and making drug addiction governed by criminals is often not the best way to deal with these controversial transactions.
The reason the murder ban works is that murder doesn’t have the structure of a repugnant transaction at all — it’s a lethal assault on an unwilling victim. There are no consenting parties, no buyers asking for the service, no constituency of users keen to find a workaround. A drug deal, by contrast, has two willing participants and an unwilling third party — society, or whoever the externalities fall on. That’s why the same legal apparatus produces such different results. The lesson I’d draw for policymakers is to look at the structure of the transaction before you decide what kind of regulation can possibly work. If the parties to the exchange want to be there, prohibition will mostly produce a black market and a lot of arrests. If you accept that, you can at least start asking how to make the harm smaller — fewer overdoses, fewer needles in schoolyards, less money flowing to cartels — even if you can’t make the demand disappear.
We’ve run this experiment in plain sight more than once. The United States amended its Constitution in 1920 to outlaw the sale of alcohol, and within thirteen years amended it again to undo Prohibition, because what we’d produced wasn’t a sober society but bootlegging and organised crime. The same pattern is visible right now in the international black market for kidneys — desperate patients buying organs from desperate sellers, sometimes with surgery performed outside well-equipped hospitals. Outlawing transactions that people want to engage in can drive them underground, force participants to deal with criminals, and turn ordinary patients and donors into accomplices in subverting the law. None of that is an argument for permitting everything. It’s an argument for being clear-eyed about what bans actually do once they meet a real human need on the other side.
Vikas Shah: Policymakers often seem unwilling to discuss the moral benchmark their society will actually accept. Don’t they need to understand the Overton window of morality before they can intervene effectively?
Alvin Roth: I think that’s right. There’s an Overton window of policies you can make, but that may be a wider window than the policies you can run your political campaign on. So, for instance, it might be a good idea that we should be more generous to kidney donors so that we have more kidneys. But the people who think it’s a bad idea to have paid donors, for example, feel it very strongly. Whereas most other people — when you survey Americans — they’re somewhat in favour of being able to be generous to kidney donors, but they feel it very diffusely. Unless they have kidney failure themselves, this is not something they think a lot about.
So if you were to run your presidential campaign with a plank that said “let’s pay kidney donors”, you’d be attacked by the people who think it’s a terrible idea that only terrible people have, and it wouldn’t get you a lot of extra votes because other people find more things more important to vote about. I don’t anticipate any candidate will run their campaign on an issue some people find really repugnant. On the other hand, it might be that as a policy matter, once you’ve been elected, this is the kind of thing that could improve public health a great deal. So it’s more a matter of legislators rather than politicians, in a certain sense — even though they’re the same people.
There is a striking piece of evidence here that I find consoling. With colleagues, I’ve looked at popular attitudes in Germany, Spain, the Philippines and the United States toward three controversial markets: prostitution, surrogacy and global kidney exchange. The legal pictures across those four countries are very different — in fact, almost mirror images of each other on prostitution. But large majorities in all four countries support legalising surrogacy and kidney exchange. So there is not, in fact, a simple relation between what voters say they would tolerate and what their legislators have made legal. The Overton window for what can be legislated is genuinely wider than the window for what can be campaigned on, and if reformers and policymakers were a bit braver about that gap, we could improve a lot of lives.
Vikas Shah: What is it about money that changes the moral meaning of a transaction? ‘My brother, I shall give you my kidney’ is admired; ‘my brother, I will sell you my kidney’ feels different.
Alvin Roth: It does. Money is a great market design invention, and we now have thousands of years of human experience with it. There’s no question that it has changed human experience from when we were all tribes and kinship networks and repeated interactions among people who knew each other. One of the big effects of expanding economic interactions is that people are much more prosperous than they used to be — we live longer and healthier lives, we have many more options than hunter-gatherers did. But money allows you to deal with anonymous other people, not just your kin. And so that has a different feeling.
There are things we do in families that we would find objectionable if they were transactions. If you were to present your children with a bill for their room and board when they went off to college and say, “You’re 18, you were very expensive — we loved having you here as our children, here’s your bill,” — well, that doesn’t sit right. Even though the same goods and services have been provided, attaching a price to them changes their meaning.
The same intuition is at work in opposition to paying organ donors. People worry that introducing money will somehow contaminate what would otherwise be a beautiful gift. But you have to put that intuition next to another moral intuition — that avoidable deaths shouldn’t be readily tolerated. Banning payment is partly a way of saying that bodies aren’t goods. Yet altruism, family and solidarity haven’t come close to filling the need. There is a worldwide shortage of kidneys. Much of the world’s plasma supply is sustained by paid American donors — the United States is, in a sense, the Saudi Arabia of blood plasma, exporting tens of billions of dollars’ worth of lifesaving plasma products every year to countries that cannot collect enough domestically from unpaid donors. So our two moral intuitions — that money shouldn’t intrude here, and that we shouldn’t tolerate avoidable death — are in conflict. Acknowledging that conflict openly is more honest than pretending one of them simply doesn’t exist.
Vikas Shah: That opens a question about vulnerability. Privileged people are forbidding poorer people from choices they might rationally prefer — are we inadvertently removing their moral agency?
Alvin Roth: I think you’re quite right. In today’s newspaper in the United States we have the Supreme Court intervening in an injunction by a Louisiana court that said abortion pills could not be sent through the mail, and the Supreme Court will once again revisit the question of abortion, which has been so controversial in the United States. But what’s the effect of preventing abortion medications being sent by mail? It prevents poor women who can’t drive from Louisiana to a nearby state that allows abortion from getting abortions — but it doesn’t prevent rich women from getting them.
Similarly, laws against surrogacy in France, Spain or what used to be West Germany prevent poor people from coming to California to have a surrogate birth, but not rich people. So often bans that are porous put up barriers that primarily affect the poor more than the rich.
This is one of the most uncomfortable patterns the book asks readers to sit with. Many bans are presented as protections for vulnerable people, and some genuinely are. But the same policy can play two different roles in the same society. For a wealthy person, a domestic ban is an inconvenience — a flight, a hotel, a clinic abroad. For a poor person it is the difference between having access to something and not. We have to be very honest with ourselves about which of those people we are protecting when we draw the line where we do, and whether the label “vulnerable” is sometimes being used to deny opportunities to the poor that the more fortunate quietly take for granted.
Vikas Shah: Your Nobel-recognised work on kidney exchange designed around moral repugnance to enable an efficient market. Do we need to think more laterally about designing such markets — or do we just need to get more comfortable with how markets work?
Alvin Roth: Well, I think both of those things are true. The question of kidney exchange is that there’s widespread repugnance about the idea of paying someone to be a kidney donor. So kidney exchange — which I’ve done a lot of work on — is a way of helping to alleviate the enormous shortage of kidneys for transplant by allowing more living donation kidneys to happen, because sometimes you are healthy enough to give someone a kidney, but you can’t give it to the person you love because your kidney doesn’t match them.
In kidney exchange, patients can get a compatible kidney from another patient’s donor. So that’s a way of increasing the number of living-donor transplants without using money. Now, nevertheless, most people who need a kidney transplant will die without getting one. So we’ve helped thousands of people get kidneys, but that’s not enough. Once again, we should probably be reconsidering whether we can be more generous to kidney donors and have more kidneys.
When my colleagues Tayfun Sönmez, Utku Ünver and I first wrote down how kidney exchange could be organised at scale, in the early 2000s, we were trying to remove a very particular obstacle. A donor would come forward, often a spouse or a sibling, willing and healthy, and the team would discover that the immune systems didn’t match. Until then, that donor was sent home and the patient stayed on the waiting list. Kidney exchange takes two such incompatible patient–donor pairs and lets them swap, so that each patient receives a compatible kidney. That basic idea has now generalised into much more elaborate structures. Non-directed donors — people who simply want to donate a kidney to a stranger — can now initiate long chains, where their gift unlocks a whole sequence of transplants, sometimes ending with a kidney going to a patient on the deceased-donor waiting list. Some of these chains have produced tens of transplants from a single altruistic donor. They are, in a small way, one of the most encouraging stories about human reliability — economic models predict that bridge donors, who receive their kidney before they donate, would often renege; in practice, voluntary breaks in the chain are very rare. People mostly do the thing they said they would do.
It hasn’t been frictionless, even in the United States. The 1984 National Organ Transplant Act bans “valuable consideration” for an organ for transplant, and there was a lingering question for years whether kidney exchange itself fell foul of that. In December 2007 Congress amended the law — the Norwood Act — to make clear that it didn’t. That amendment passed unanimously in both the House and the Senate. So kidney exchange, in the end, didn’t arouse any congressional repugnance at all. But the picture elsewhere was different. The first kidney exchange in Europe was performed in 1999 between a German pair and a Swiss pair, in Switzerland; when it was reported in the medical literature, German news media denounced the German surgeon involved as an organ trafficker. To this day, in Germany and Brazil, you can only receive a living-donor transplant from a member of your own family — a rule designed to prevent payment, but which incidentally rules out almost all kidney exchange too.
The most morally interesting frontier of this work, for me at the moment, is what we call Global Kidney Exchange. The basic insight is that there are two very different kinds of barrier to transplantation in the world. In wealthy countries with good health systems, the barrier is often immunological — highly sensitised patients who can’t find a compatible donor anywhere in their own country, even one as large as the United States. In middle-income countries, the barrier is often financial — patients have a willing, healthy, compatible donor in the family, but their health system can’t pay for the transplant or for long-term post-transplant care. Pair them up, and both patients can be transplanted. The American patient gets the compatible kidney they couldn’t otherwise find; the foreign patient gets the operation and the follow-up care that would otherwise have been impossible. Loosely speaking, a transplant costs about as much as a year of dialysis, but after a year of dialysis you need another year, while post-transplant care is much cheaper — so there’s room in the savings to fund the whole arrangement.
I traveled with the transplant surgeon Mike Rees, one of the pioneers of kidney exchange, to Geneva and Rome to talk about this. We met with the Red Crescent Society in the United Arab Emirates — the Islamic counterpart of the international Red Cross — to discuss the first kidney exchange between Israel and the UAE, which involved three patient–donor pairs, including one Muslim-Israeli couple, one Jewish-Israeli pair, and one Arab pair from the UAE. The Red Crescent sheik we spoke with said something I’ve thought about ever since. We had described the various restrictions on payments to donors in the West, and Mike mentioned how he’d been criticised for buying winter shoes for a Filipino patient–donor pair who arrived at Detroit airport in flip-flops, and I mentioned a Filipino patient who, post-transplant, needed a motorbike with a sidecar to restart his taxi business. The sheik said: “That would just be giving his life back. We could do that.” And yet, when I gave a talk on Global Kidney Exchange in Geneva, a Spanish physician then directing transplantation policy at the World Health Organization argued that we had exploited the Filipino patient. When I replied that, without the exchange, that patient would have died, the WHO director exclaimed, “He should be dead!” That moment captures, more sharply than any abstract framing I could offer, how repugnance can travel under the disguise of ethics, and why moral economics is worth doing carefully.
Vikas Shah: Vaccine challenge trials fascinated me — the trade-off where letting more people die through delay feels less troubling than actively exposing consenting volunteers to danger. Why is this case so prescient?
Alvin Roth: Well, here we had the COVID pandemic that really killed a lot of people directly, and it also shut down a lot of the world economy as we all stayed home, wore masks, tried to work remotely — but not everyone could. We kept children home from school. It was a massive worldwide upheaval. And part of the problem was that there wasn’t yet a vaccine. Vaccines were developed very quickly, but they could have been developed more quickly.
One of the organisations I write about in the book is called 1Day Sooner. The name is meant to suggest that getting vaccines available to many people even one day sooner would be very valuable. They enlisted lots of volunteers — tens of thousands of people, from around the world — who were willing to take part in human challenge trials. Let me take a step back and explain how vaccines are developed.
Once you have a vaccine, you need to test whether it works. The way we ultimately did it for COVID is you find a place where there’s a hotspot, you enrol 40,000 potential test subjects, you give 20,000 of them the vaccine and 20,000 of them a placebo. Then you wait some number of months, because even in a hotspot, people in their ordinary course of events aren’t going to get COVID. Most people don’t get COVID in any three-month period. But after three or four months, enough additional people will have got COVID in the placebo group, compared to the vaccine group, that you can determine whether the vaccine is successful. So months go by, 40,000 people are involved, and during those months many people die in the wider pandemic — billions of people in the world are exposed.
The alternative is to take a very small number — a few dozen — of healthy young volunteers, drip the virus into their noses so that many of them will quickly get COVID instead of a small percentage, give half of them the vaccine and half not, and then see whether the vaccinated group catches the disease at a much lower rate. That can be a matter of weeks. Of course, the problem — especially for COVID — was that, at the time we needed the vaccine, we didn’t yet have a cure. But twenty-, twenty-five-year-old healthy people weren’t at great risk of dying. There were many volunteers willing to do that to contribute to the worldwide fight against this pandemic. But we didn’t allow them to.
What makes the case so striking is that the actual numbers came in. The Pfizer phase three trial enrolled more than forty thousand people and took about four months to see one hundred and seventy COVID cases among them — fewer than one percent of participants got infected in that time. The British did run a small phase one challenge trial, and they got over half their participants infected within five days, with no serious illness. So a few dozen volunteers, properly cared for, generated more than fifty times the infection rate of the conventional trial in a tiny fraction of the time. The bioethics objection wasn’t really about the volunteers’ safety in the end — it was that deliberately exposing them felt like an act of commission, where letting the pandemic kill more people while we waited felt like an act of omission. But the people who would have died in the meantime were just as dead either way. That asymmetry between commission and omission is one of the deepest moral biases the book asks us to confront.
There’s a second, related question in there about pay. Soldiers get combat pay; coal miners earn more than equivalently skilled workers in safer jobs in the same town. We pay people more for risky work as a matter of course. With my colleagues Sandro Ambuehl and Axel Ockenfels I argued that paying challenge-trial volunteers a stipend per hour, as some proposed, was actually the wrong design — because the risk in a challenge trial isn’t really a function of how long you spend in it. We put it this way: some risky tasks take very little time. Imagine running a challenge trial to test bulletproof vests. The exposure is over in seconds, but the relevant risk is the whole reason you’re being paid at all. The bigger lesson is that medical ethics has had a long-standing discomfort with paying people for risky work, but in almost every other domain we accept it, and we honour the people who do it.
Vikas Shah: The ultimate extension is when you write about your friend Professor Kahneman travelling to Switzerland — that deep connection between autonomy, dignity and the morality of the market. How should we think about the assisted dying debate, and how can a ban paradoxically cause people to go sooner?
Alvin Roth: Yes — let me separate those and go back first to vaccines, because you talked about dignity and autonomy. We allow people to put themselves in danger. Firefighters put themselves in danger when everyone is running out of a burning building — the firefighters are supposed to go in on their knee pads, in the smoke, to look for people who have been disabled by the smoke. And we pay them for it. It’s a job. You can earn your living by fighting fires and saving lives, and we’re happy for it. But we decided we weren’t going to allow people to do this with testing vaccines for COVID. We allow people to risk their lives to save other people’s lives — but here we didn’t, partly because pharmaceutical companies have to worry about lawsuits and liabilities and things like that. It’s as though we sort of said: instead of having firefighters, let’s let fires burn out, and many people will escape on their own. We could do that — but we don’t. We allow firefighters and we think it’s honourable, we honour them, we are saddened when they die in the line of work, and they sometimes do. But we allow them to be firefighters, to earn their living that way, and we’re proud of them and they’re proud of themselves. We didn’t allow people to test vaccines that way.
Now to medical aid in dying, which has been a big controversy in England as well as here. One of the things that happens in England, as you know, is that people sometimes accompany loved ones who are dying slowly and agonisingly to Switzerland, where the law allows people to end their lives with medical assistance — so not messily, not in single-car accidents or with gunshots.
Around twelve, maybe thirteen US jurisdictions now allow medical aid in dying — New York State will allow it this August, which is why I’m not quite sure if it’s twelve or thirteen. In the United States, we only allow it in cases of imminent death. You have to have a terminal diagnosis, a team of doctors has to think the candidate will be dead in six months without aid in dying, and so the medical aid comes in easing the dying process. But in Canada, our neighbour to the north, they have a much more liberal medical-aid-in-dying policy.
The Canadian Supreme Court had an interesting set of opinions about that. They said Canadians are guaranteed security in their lives. If we didn’t have medical aid in dying, then there would be people who would worry that, as their diseases progressed, they would be unable to take their own lives — and who might therefore feel compelled to take their own lives now, while they still could, rather than be at the mercy of their disease. Therefore, said the Canadian Supreme Court, we’re going to allow medical aid in dying so that no one feels they have to pre-emptively take their own life.
That argument is, to my mind, one of the most important and least understood parts of this whole debate. People who are reflexively opposed to medical aid in dying often picture it as something that pulls people towards an earlier death. The Canadian court’s reasoning is the opposite — that the absence of a humane, regulated option pushes some people to act sooner, while they still physically can. Danny Kahneman travelled to Switzerland for reasons of his own, but the same logic applied to him. He had the resources to go. Most people facing a long, undignified decline don’t, and the policies we choose decide whether their last months are spent on their own terms or someone else’s.
Vikas Shah: How do we reason together when consensus is unlikely, and the topics intersect with the most sacred values people hold?
Alvin Roth: I think that those of us who have sacred values have to consider what to do when we can’t achieve them. Suppose we all condemn murder and heroin. We’re not able to abolish either of them. On the other hand, overdose deaths in the United States are much greater than all causes of homicide. We have many, many fewer deaths from murder than we have from overdoses. So we’re much less successful in our desire to ban heroin than in our desire to ban murder, although we’re not perfectly successful in either case.
We have to think about what to do about that. We don’t like heroin for many reasons, but one of those reasons is overdose deaths. So given that we can’t control heroin as much as we would like, we could start to think about how to control overdose deaths even in the absence of gaining control over heroin. That’s a discussion about whether we should start treating addicts more like patients than like criminals.
But it’s complicated, because cities — in some places, countries that have decriminalised heroin — find that it starts to make some of their cities unliveable. It leads to open-air drug markets and hypodermic needles in schoolyards, and all sorts of things that are also very costly. So that’s the market I know least about how to proceed in. But that’s an argument for experimentation. And when I say experimentation, I mean Portugal has some experience with decriminalising drugs. We can look around the world and try to learn from experience.
Portugal decriminalised possession of small quantities of all drugs back in 2001, and the early evidence was promising — fewer overdoses, no surge in addiction. Oregon followed in 2020, and British Columbia in 2023. But by 2024, all three were rolling back or revising those policies, because addiction and drug use had become very public and the cities were deteriorating; addictive drugs had become much more available than treatment. So the lesson isn’t that decriminalisation works or doesn’t work, in some absolute sense — it’s that decriminalisation by itself is not a policy, it’s the absence of part of a policy. If you remove criminal penalties without massively investing in treatment, harm reduction and recovery infrastructure, you have removed only the part of the system that was suppressing visibility, not the part that was producing addiction. The honest version of this debate accepts that we need better evidence, that experiments themselves are how we generate that evidence, and that we should be willing to learn — and to change our minds — when the evidence comes in.
Vikas Shah: As a roundup — the road ahead. You’ve shown that technology creates possibilities before we have the language to understand them. With CRISPR, AI and what’s coming, how can we be more adaptive to the new frontiers of repugnance you anticipate?
Alvin Roth: I think we have to struggle with it. The method we adopt and adapt to these things is, some of it traditional marketplace methods and some of it democracy. We debate with each other. We elect candidates who take positions. We try to make legislation that eases hardships. I don’t think we can expect this process to go away. As you say, AI is going to present lots of new technological possibilities.
One of the things I talk about in the book is how reproductive technologies changed a lot. In vitro fertilisation: a British biologist, Robert Edwards, won the 2010 Nobel Prize for developing IVF. By the time he won the prize, millions of people had already been born through assisted reproductive technology. But at the same time, some people thought he was a murderer — because when you do IVF, you typically create more than one embryo, and if not all of the embryos are brought to birth, some people regarded that as murder. So you can have the most intense disagreements. There are millions of people who regard IVF as life-giving — it gave them life, it gave their children life. And there are other people who regard it as murder. I don’t expect that everyone will agree all the time, but we as societies must decide what we support and what we don’t. Both markets and bans on markets require substantial social support in order to work well.
It’s worth pausing on Edwards’s story for a moment, because it captures the whole pattern in miniature. He worked for years with the Oldham gynaecologist Patrick Steptoe — beginning in the 1950s — through enormous public hostility. The New York Times ran a piece in 1974 headlined “The Embryo Sweepstakes,” with the subheading “The winner will be a brave new baby conceived in a test-tube and then planted in a womb.” James Watson, of all people, told Congress that if IVF were to go forward, “all hell will break loose, politically and morally, all over the world.” Then in 1978 Louise Brown was born in Oldham — the first IVF baby. Four years later her sister Natalie became the fortieth. By the time Edwards’s Nobel Prize was finally awarded in 2010, he was celebrated at the televised banquet in Stockholm City Hall with trumpets — and on that very same day, the Vatican’s spokesman on bioethics told the BBC that giving him the prize was “completely out of order,” because in IVF embryos that aren’t transferred “will end up abandoned or dead, which is a problem for which the new Nobel prize winner is responsible.” Same person, same achievement, same day — celebrated as a saviour by some, condemned as a murderer by others. That is what a real moral controversy looks like. It doesn’t dissolve, even after the technology has changed millions of lives.
The IVF story is, in a way, the template for what we should expect with every wave of new biological and computational technology. CRISPR will let us edit human germ lines; the question of which edits are repair and which are enhancement is going to be argued out the same way that IVF, surrogacy, abortion and same-sex marriage have been — slowly, unevenly, country by country, with technology consistently outpacing the moral language we have available. AI will create new matching markets, new forms of advice and authorship, new questions about what kinds of decisions we are willing to delegate to machines and what kinds we want to keep for ourselves. I don’t think we will resolve any of these questions cleanly. But I do think we will do better if we take the lessons from the older controversies seriously: that bans don’t make the underlying transactions disappear; that markets without social support fail just as surely as bans without social support; and that the most useful contribution an economist can make is usually to lay out the tradeoffs honestly, gather the best available evidence, and design rules that can be revised as we learn more.
Vikas Shah: A final question that’s been on my mind. When you think about the impact you’re making on this little blue marble, what does legacy mean to you?
Alvin Roth: That’s a good question, and I’ll be able to think about it when I retire. Until then — often people say to me, “You must be so pleased with the effects your work has had.” But I have to admit, the daily feeling is frustration. There’s much more to do. For kidney transplantation, I could tell you about victory after victory in a war that we’re losing — because the shortage of transplants is growing rather than shrinking, as diabetes and hypertension become an epidemic. Often my feeling is, “Gee, there’s so much to do, so little time, it’s so hard to be persuasive.” When I’m safely retired or maybe dead for a couple of generations, it’ll be easier to talk about legacy.