Al Roth never graduated from high school. He holds an honorary seventh-degree black belt from the Japan Karate Association. And in 2012, he won the Nobel Prize in Economics for designing the algorithm that matches unrelated kidney donors with recipients — a piece of market engineering that has, by any honest accounting, saved lives.
None of that is what his new book is about.
Moral Economics: From Prostitution to Organ Sales, What Controversial Transactions Reveal about How Markets Work, published in May, is something rarer in academic economics: a provocation with a footnote apparatus. Roth moves through one prohibited or contested transaction after another — buying sex, eating horses, selling organs, assisting suicide, carrying a stranger's baby — and asks, in what he describes as a 'mild, just-asking-questions tone,' why so many of these activities remain restricted or banned even when consenting adults clearly want to engage in them.
The animating concept is one Roth uses as a technical term: repugnance. Not a moral verdict, but a description of the social mechanism by which certain markets get blocked before anyone has seriously examined the trade-offs. Iran, he notes, is the only country in the world where selling a kidney is legal. Everywhere else, the waiting lists grow and people die, while the transaction that might clear those lists sits prohibited — not because the evidence says it causes harm, but because enough people find the idea distasteful.
That is the core of Roth's argument, and it is worth sitting with. Markets are not natural phenomena. They are designed — by law, by regulation, by social consensus, and sometimes by the accumulated weight of disgust that has never been examined under cross-examination. Roth's career has been spent designing better ones, most famously the kidney-matching algorithm, which works precisely because it routes around the taboo on direct payment while still enabling exchange.
The book does not argue that every repugnant market should be opened. It argues that the question should be asked seriously, with attention to who bears the cost of prohibition. In the case of kidneys, that cost is measurable and falls on identifiable people. In the case of other restricted markets — commercial surrogacy, assisted dying, even horse meat — the distribution of costs and benefits is less obvious but no less real.
Follow the incentive, not the press release. That is the discipline Roth applies, and it is the discipline that makes Moral Economics worth reading regardless of where you land on any individual question.
The Signal's read: what Roth is really documenting is the cost of allowing visceral reaction to substitute for policy analysis. Every market blocked by repugnance rather than evidence is a market where the people who most need the transaction — and who are least able to afford alternatives — pay the price. Free enterprise does not mean every exchange is wise or dignified. It means the burden of proof belongs to those who would prohibit, not to those who would transact. Roth, characteristically, does not say that. He just lays out the record and lets it speak.
