Global kidney chains.

Kidney failure is a worldwide scourge, made more lethal by the shortage of transplants. We propose a way to organize kidney exchange chains internationally between middle-income countries with financial barriers to transplantation and high-income countries with many hard to match patients and patient-donor pairs facing lengthy dialysis. The proposal involves chains of exchange that begin in the middle-income country and end in the high-income country. We also propose a way of financing such chains using savings to US health care payers.

Popular repugnance contrasts with legal bans on controversial markets.

We study popular attitudes in Germany, Spain, the Philippines, and the United States toward three controversial markets-prostitution, surrogacy, and global kidney exchange (GKE). Of those markets, only prostitution is banned in the United States and the Philippines, and only prostitution is allowed in Germany and Spain. Unlike prostitution, majorities support legalization of surrogacy and GKE in all four countries. So, there is not a simple relation between public support for markets, or bans, and their legal and regulatory status. Because both markets and bans on markets require social support to work well, this sheds light on the prospects for effective regulation of controversial markets.

Marketplaces, Markets, and Market Design.

Marketplaces are often small parts of large markets, and both markets and marketplaces come in many varieties. Market design seeks to understand what marketplaces must accomplish to enable different kinds of markets. Marketplaces can have varying degrees of success, and there can be marketplace failures. I'll discuss labor markets like the market for new economists, and also markets for new lawyers and doctors that have suffered from the unraveling of appointment dates to well before employment begins. Markets work best if they enjoy social support, but some markets are repugnant in the sense that some people think they should be banned, even though others want to participate in them. Laws banning such markets often contribute to the design of illegal black markets, and this raises new issues for market designers. I'll briefly discuss markets and black markets for narcotics, marijuana, sex, and surrogacy, and the design of markets for kidney transplants, in the face of widespread laws against (and broader repugnance for) compensating organ donors. I conclude with open questions and engineering challenges.

Complete Chain of the First Global Kidney Exchange Transplant and 3-yr Follow-up.

BACKGROUND: Global Kidney Exchange (GKE) offers an opportunity to expand living renal transplantation internationally to patients without financial means. These international pairs are entered into a US kidney exchange program that provides long-term financial support in an effort to identify opportunities for suitable exchanges for both these international pairs and US citizens. OBJECTIVE: While the promise of GKE is significant, it has been met with ethical criticism since its inception in 2015. This paper aims to demonstrate the selection process and provide >3 yr of follow-up on the first GKE donor and recipient from the Philippines. DESIGN, SETTING, AND PARTICIPANTS: The first GKE transplant occurred with a young Filipino husband and wife who were immunologically compatible, but lacked the financial means to continue hemodialysis or undergo a kidney transplant in their home country. The pair was enrolled in the Alliance for Paired Donation matching system, several alternative kidney exchanges were identified, and the pair subsequently underwent renal transplantation and donation in the USA financed by philanthropy. The resulting nonsimultaneous extended altruistic chain provided transplantation for the Filipino husband and 11 US patients. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The Filipino donor and recipient were followed by transplant professionals in both the Philippines and the USA. Follow-up data were maintained as required by the Organ Procurement and Transplantation Network in the USA. RESULTS AND LIMITATIONS: The Filipino donor has normal blood pressure and renal function, and the Filipino recipient is doing well 3.5 yr after their donation and transplantation. CONCLUSIONS: While criticisms of GKE highlight concerns for possible exploitation of financially disadvantaged groups, these results demonstrate that these concerns did not come to fruition, and the outcome experienced by the GKE donor and recipient (and other US participants) was successful. PATIENT SUMMARY: The first Filipino Global Kidney Exchange (GKE) donor-recipient pair continues to be followed by both US and Filipino transplant centers. Both are in good health, support the GKE program, and advocate for its expansion.

Incentivizing Organ Donor Registrations with Organ Allocation Priority.

How donor organs are allocated for transplant can affect their scarcity. In 2008, Israel's Parliament passed an Organ Transplantation Law granting priority on organ donor waiting lists to individuals who had previously registered as organ donors. Beginning in November 2010, public awareness campaigns advertised the priority policy to the public. Since April 2012, priority has been added to the routine medical criteria in organ allocation decisions. We evaluate the introduction of priority for registered organ donors using Israeli data on organ donor registration from 1992 to 2013. We find that registrations increased when information about the priority law was made widely available. We find an even larger increase in registration rates in the 2 months leading up to a program deadline, after which priority would only be granted with a 3-year delay. We also find that the registration rate responds positively to public awareness campaigns, to the ease of registration (i.e. allowing for registering online and by phone) and to an election drive that included placing registration opportunities in central voting locations. Copyright © 2016 John Wiley & Sons, Ltd.

Maximization, learning, and economic behavior.

The rationality assumption that underlies mainstream economic theory has proved to be a useful approximation, despite the fact that systematic violations to its predictions can be found. That is, the assumption of rational behavior is useful in understanding the ways in which many successful economic institutions function, although it is also true that actual human behavior falls systematically short of perfect rationality. We consider a possible explanation of this apparent inconsistency, suggesting that mechanisms that rest on the rationality assumption are likely to be successful when they create an environment in which the behavior they try to facilitate leads to the best payoff for all agents on average, and most of the time. Review of basic learning research suggests that, under these conditions, people quickly learn to maximize expected return. This review also shows that there are many situations in which experience does not increase maximization. In many cases, experience leads people to underweight rare events. In addition, the current paper suggests that it is convenient to distinguish between two behavioral approaches to improve economic analyses. The first, and more conventional approach among behavioral economists and psychologists interested in judgment and decision making, highlights violations of the rational model and proposes descriptive models that capture these violations. The second approach studies human learning to clarify the conditions under which people quickly learn to maximize expected return. The current review highlights one set of conditions of this type and shows how the understanding of these conditions can facilitate market design.

Organ Allocation Policy and the Decision to Donate.

Organ donations from deceased donors provide the majority of transplanted organs in the United States, and one deceased donor can save numerous lives by providing multiple organs. Nevertheless, most Americans are not registered organ donors despite the relative ease of becoming one. We study in the laboratory an experimental game modeled on the decision to register as an organ donor and investigate how changes in the management of organ waiting lists might impact donations. We find that an organ allocation policy giving priority on waiting lists to those who previously registered as donors has a significant positive impact on registration.

The art of designing markets.

Traditionally, markets have been viewed as simply the confluence of supply and demand. But to function properly, they must be able to attract a sufficient number of buyers and sellers, induce participants to make their preferences clear, and overcome congestion by providing both enough time to make choices and a speedy means of registering them. Solutions to these challenges are the province of market design--a blend of game theory and experimental economics. Roth, a professor of both business and economics at Harvard, is a leading market designer. He and his colleagues have rescued failing markets by, for example, designing labor clearinghouses through which U.S. doctors get their first jobs and auctions through which the Federal Communications Commission sells licenses for parts of the radio broadcast spectrum. They have also created marketlike allocation procedures that involve neither prices nor an exchange of money; these include systems for assigning children to schools in Boston and New York and for facilitating exchanges of kidneys. Computers enable the design of "smart markets" that combine the inputs of users in complex ways: In kidney exchange, they run through every possible match of donors and recipients to arrange the greatest possible number of transplants. In the future, computers may make it possible to auction bundled goods, such as airport takeoff and landing slots. As online markets--like those for jobs and dating--proliferate, a growing understanding of markets in general will provide virtually limitless opportunities for market design.

The Gastroenterology Fellowship Market: Should There Be a Match?

We are helping a task force of the American Gastroenterology Association to evaluate the current state of the (decentralized) market for gastroenterology fellows, and to assess the prospects of reorganizing it via a suitably designed centralized clearinghouse, a "match." This market used a match from 1986 until the late 1990s. Starting in 1996, participation in the match declined precipitously, and it was formally abandoned after 1999. Consequently, the experience of this market when the match was in place, in comparison to the periods before and since, allows an assessment of the effects of the match. An analysis of how the match failed in the 1990s yields insights into the prospects for success of a new match. These events offer economists a rare window on how decentralized labor markets clear, and on how market clearinghouses succeed and fail.

The gastroenterology fellowship Match: how it failed and why it could succeed once again.

The market for gastroenterology (GI) fellows adopted a centralized Match in 1986, and abandoned it in the late 1990s. We discuss why the Match initially was adopted, how and why it broke down, what differences this has made in the market for fellows, and what would be needed to restart the Match successfully. We assess the effects of the Match by comparing the GI fellows market now with when the Match was operating, and with the fellowship markets for internal medicine subspecialties that continue to use a Match. The breakdown of a well-functioning Match is rare, but may be caused by unusual shifts in market conditions, such as those experienced by gastroenterology in the late 1990s. The problems the gastroenterology Match originally was designed to solve re-emerged with the demise of the Match. The market has become more local and less national, than when there was a Match in place, and program recruitment of fellows occurs earlier and is more dispersed in time than internal medicine subspecialties that continue to use a Match. There is no evidence that the demise of the Match has had any effect on wages. The evidence strongly suggests that the Match could be reintroduced successfully, which would increase the mobility of potential GI fellows, allow potential fellows to compete for the widest range of programs, and allow programs to compete for the widest range of fellows.

The Nash equilibrium: a perspective.

In 1950, John Nash contributed a remarkable one-page PNAS article that defined and characterized a notion of equilibrium for n- person games. This notion, now called the "Nash equilibrium," has been widely applied and adapted in economics and other behavioral sciences. Indeed, game theory, with the Nash equilibrium as its centerpiece, is becoming the most prominent unifying theory of social science. In this perspective, we summarize the historical context and subsequent impact of Nash's contribution.