Trading kidneys, repugnant markets and stable marriages win the Nobel Prize in Economics

Roth and Shapley charted a course for economists to go beyond simply arguing for markets in everything.

The 2012 Nobel Prize in Economics - technically the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel, but nobody cares - has been awarded to two American Economists, Alvin Roth and Lloyd Shapley "for the theory of stable allocations and the practice of market design". The Nobel Committee explains what that means:

This year's Prize concerns a central economic problem: how to match different agents as well as possible. For example, students have to be matched with schools, and donors of human organs with patients in need of a transplant. How can such matching be accomplished as efficiently as possible? What methods are beneficial to what groups? The prize rewards two scholars who have answered these questions on a journey from abstract theory on stable allocations to practical design of market institutions.

Lloyd Shapley used so-called cooperative game theory to study and compare different matching methods. A key issue is to ensure that a matching is stable in the sense that two agents cannot be found who would prefer each other over their current counterparts. Shapley and his colleagues derived specific methods – in particular, the so-called Gale-Shapley algorithm – that always ensure a stable matching. These methods also limit agents' motives for manipulating the matching process. Shapley was able to show how the specific design of a method may systematically benefit one or the other side of the market.

Alvin Roth recognized that Shapley's theoretical results could clarify the functioning of important markets in practice. In a series of empirical studies, Roth and his colleagues demonstrated that stability is the key to understanding the success of particular market institutions. Roth was later able to substantiate this conclusion in systematic laboratory experiments. He also helped redesign existing institutions for matching new doctors with hospitals, students with schools, and organ donors with patients. These reforms are all based on the Gale-Shapley algorithm, along with modifications that take into account specific circumstances and ethical restrictions, such as the preclusion of side payments.

Even though these two researchers worked independently of one another, the combination of Shapley's basic theory and Roth's empirical investigations, experiments and practical design has generated a flourishing field of research and improved the performance of many markets. This year's prize is awarded for an outstanding example of economic engineering.

The committee have yet again reaffirmed the old adage that the most important thing to do when trying for a nobel prize is to live long enough that your achievements are recognised. The Gale-Shapley algorithm, for instance, was devised in 1962, when Lloyd Shapley was 34. It concerns a maths problem known as the stable marriage problem: if you have an even number of men and women, can you always come up with a set of marriages where there are no two people of opposite sex who would both rather have each other than their current partners? (1960s maths problems: usually heteronormative.) If you can, then the marriage is "stable".

The Gale-Shapley algorithm is a way of always ensuring stable matches; and much of Shapley's work covers the same areas, straddling the boundaries between economics, mathematics, and computer science.

Roth is the younger of the two winners, and works in a far more empirical sphere. As the committee points out, although the two men never actually collaberated, Roth took Shapley's theoretical work and applied it to actually existing markets. For instance, Roth used the Gale-Shapley agorithm to ease the kidney shortage in the US. David Wessel explains (£):

As of noon yesterday, 58,470 people in the U.S. were waiting for a kidney transplant. Most won't get one this year. There aren't enough donated kidneys to go around. Surgeons transplanted just 15,129 kidneys last year. Now a band of transplant surgeons and economists are trying to fix that by creating a moneyless market for exchanging kidneys. Most transplanted kidneys come from a person who has died, a supply that grows slowly because of ignorance about the need for donations or grieving relatives' reluctance. But a kidney taken from a live donor works better, and almost everyone has a spare. As techniques improve for removing healthy kidneys and for suppressing the body's tendency to reject a transplant, doctors increasingly turn to kidneys from living donors, usually relatives. Last year, 43% of kidneys transplanted in the U.S. came from living donors, up from 28% a decade ago. But a biological barrier often blocks a transplant from a relative. In about a third of all would-be pairs, blood types are incompatible. In others, the sick person has antibodies that can initiate a rejection of the donated organ. It's heartbreaking "to have the treasure of the live donor and then have that not go forward because of a biological obstacle," says Massachusetts General Hospital transplant surgeon Francis DelMonico.

Occasionally, transplant centers spot a way out: One New England father with blood type A couldn't donate a kidney to his daughter with blood type B. So he gave a kidney to a teenager with blood type A, and the teenager's sister gave a kidney for the man's daughter. New England's transplant centers have done six such exchanges. Baltimore's Johns Hopkins University has done seven.

The crucial thing about Roth's work, from an economic point of view, is that it involves finding stable allocations using market-like situations without involving money. The kidney swaps in the New England situation are market-like, trading kidneys for kidneys in a way that makes all parties better-off, but they don't actually require kidneys to be bought and sold.

We can see the importance of this by looking at another paper of Roth's, not cited by the committee, on repugnance in markets (pdf). Roth demonstrates that some markets are limited because the very existance of a market in some goods is considered repugnant. He argues, for instance, that the trade in horse meat being banned in California is not done through fears that eating horse meat is unsafe; nor is it done for animal welfare reasons, since it is still legal to farm and kill horses. But banned it is, and Roth argues that the natural response of economists to situations of this type - to argue for freer markets - is wrong, since it ignores the very strong feelings involved in the situation. Instead:

Being aware of the sources of repugnance can only help make such discussions more productive, not least because it can help separate the issues that are fundamentally empirical—like the degree of crowding out of altruistic donations that might result from different incentive schemes compared to how much new supply might be produced—from areas of disagreement that are not primarily empirical.

Hopefully his new Nobel Prize should give that argument greater weight in the years ahead.

A patient receives a kidney in Johns Hopkins university in Baltimore. Photograph: Getty Images

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

ELLIE FOREMAN-PECK FOR NEW STATESMAN
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Craig Oliver, Cameron's attack dog, finally bites

A new book reveals the spiteful after life of Downing Street's unlikely spin doctor.

It must be hard being a spin doctor: always in the shadows but always on-message. The murky control that the role requires might explain why David Cameron’s former director of communications Craig Oliver has rushed out his political memoirs so soon after his boss left Downing Street. Now that he has been freed from the shackles of power, Oliver has chosen to expose the bitterness that lingers among those on the losing side in the EU referendum.

The book, which is aptly titled Unleashing Demons, made headlines with its revelation that Cameron felt “badly let down” by Theresa May during the campaign, and that some in the Remain camp regarded the then home secretary as an “enemy agent”. It makes for gripping reading – yet seems uncharacteristically provocative in style for a man who eschewed the sweary spin doctor stereotype, instead advising Cameron to “be Zen” while Tory civil war raged during the Brexit campaign.

It may be not only politicians who find the book a tough read. Oliver’s visceral account of his side’s defeat on 24 June includes a description of how he staggered in a daze down Whitehall until he retched “harder than I have done in my life. Nothing comes up. I retch again – so hard, it feels as if I’ll turn inside out.”

It’s easy to see why losing hit Oliver – who was knighted in Cameron’s resignation honours list – so hard. Arguably, this was the first time the 47-year-old father-of-three had ever failed at anything. The son of a former police chief constable, he grew up in Scotland, went to a state school and studied English at St Andrews University. He then became a broadcast journalist, holding senior posts at the BBC, ITV and Channel 4.

When the former News of the World editor Andy Coulson resigned as No 10’s communications director in January 2011 because of unceasing references in the press to his alleged involvement in the phone-hacking scandal, Oliver was not the obvious replacement. But he was seen as a scandal-free BBC pen-pusher who exuded calm authority, and that won him the job. The Cameron administration, tainted by its association with the Murdoch media empire, needed somebody uncontroversial who could blend into the background.

It wasn’t just Oliver’s relative blandness that recommended him. At the BBC, he had made his name revamping the corporation’s flagship News at Ten by identifying the news angles that would resonate with Middle England. The Conservatives then put this skill to very good use during their 2015 election campaign. His broadcast expertise also qualified him to sharpen up the then prime minister’s image.

Oliver’s own sense of style, however, was widely ridiculed when he showed up for his first week at Downing Street looking every inch the metropolitan media male with a trendy man bag and expensive Beats by Dre headphones, iPad in hand.

His apparent lack of political affiliation caused a stir at Westminster. Political hacks were perplexed by his anti-spin attitude. His style was the antithesis of the attack-dog mode popularised by Alastair Campbell and Damian McBride in the New Labour years. As Robert Peston told the Daily Mail: “Despite working closely with Oliver for three years, I had no clue about his politics or that he was interested in politics.” Five years on, critics still cast aspersions and question his commitment to the Conservative cause.

Oliver survived despite early wobbles. The most sinister of these was the allegation that in 2012 he tried to prevent the Daily Telegraph publishing a story about expenses claimed by the then culture secretary, Maria Miller, using her links to the Leveson inquiry as leverage – an accusation that Downing Street denied. Nevertheless, he became indispensable to Cameron, one of a handful of trusted advisers always at the prime minister’s side.

Newspapers grumbled about Oliver’s preference for broadcast and social media over print. “He’s made it clear he [Oliver] doesn’t give a s*** about us, so I don’t really give a s*** about him,” a veteran correspondent from a national newspaper told Politico.

Yet that approach was why he was hired. There was the occasional gaffe, including the clumsy shot of a stern-looking Cameron, apparently on the phone to President Obama discussing Putin’s incursion into Ukraine, which was widely mocked on Twitter. But overall, reducing Downing Street’s dependence on print media worked: Scotland voted against independence in 2014 and the Tories won a majority in the 2015 general election.

Then came Brexit, a blow to the whole Cameroon inner circle. In his rush to set the record straight and defend Cameron’s legacy – as well as his own – Oliver has finally broken free of the toned-down, straight-guy persona he perfected in power. His memoir is spiteful and melodramatic, like something straight from the mouth of Malcolm Tucker in The Thick of It. Perhaps, with this vengeful encore to his mild political career, the unlikely spin doctor has finally fulfilled his potential. 

This article first appeared in the 29 September 2016 issue of the New Statesman, May’s new Tories