Market Design Working Group Meeting October 22-24, 2020

 The NBER market design conference in October now has a program:

Market Design Working Group Meeting October 22-24, 2020, via Zoom

Michael Ostrovsky and Parag A. Pathak, Organizers

Times are eastern daylight time

Thursday, October 22

12:00 pm

Susan Athey, Stanford University and NBER

Arthur Baker, Harvard University

Juan Camilo Castillo, University of Pennsylvania

Rachel Glennerster, DFID

Scott Duke Kominers, Harvard University

Michael Kremer, Harvard University and NBER

Jean Nahrae Lee, World Bank

Christopher Snyder, Dartmouth College and NBER

Alex Tabarrok, George Mason University

Brandon Tan, Harvard University

Accelerating a Covid-19 Vaccine

12:45 pm

Parag A. Pathak, Massachusetts Institute of Technology and NBER

Tayfun Sönmez, Boston College

M. Utku Ünver, Boston College

M. Bumin Yenmez, Boston College

Fair Allocation of Vaccines, Ventilators and Antiviral Treatments: Leaving No Ethical Value Behind in Health Care Rationing

1:30 pm

Open Discussions

2:00 pm

Xiang Han, Shanghai University of Finance and Economics

Onur Kesten, Carnegie Mellon University

M. Utku Ünver, Boston College

Blood Allocation with Replacement Donors

2:45 pm

Mohammad Akbarpour, Stanford University

Afshin Nikzad, University of Southern California

Michael A. Rees, University of Toledo Medical Center

Alvin E. Roth, Stanford University and NBER

Global Kidney Chains

3:30 pm

Open Discussions

4:00 pm

Adjourn

Friday, October 23

12:00 pm

Chiaki Moriguchi, Hitotsubashi University

Yusuke Narita, Yale University

Mari Tanaka, Hitotsubashi University

Meritocracy and Its Discontents: Long-Run Effects of Repeated School Admission Reforms

12:45 pm

Yan Chen, University of Michigan

Ming Jiang, Shanghai Jiao Tong University

Onur Kesten, Carnegie Mellon University

An Empirical Evaluation of Chinese College Admissions Reforms Through A Natural Experiment

1:30 pm

Open Discussions

2:00 pm

Adam Kapor, Princeton University and NBER

Mohit Karnani, Massachusetts Institute of Technology

Christopher Neilson, Princeton University and NBER

Aftermarket Frictions and the Cost of Off-Platform Options in Centralized Assignment Mechanisms

2:45 pm

David Delacretaz, University of Oxford

Processing Reserves Simultaneously

3:30 pm

Open Discussions

4:00 pm

Adjourn

Saturday, October 24

12:00 pm

Federico Echenique, California Institute of Technology

Antonio Miralles, Universita' degli Studi di Messina

Jun Zhang, Nanjing Audit University

Constrained Pseudo-Market Equilibrium

12:45 pm

Marzena Rostek, University of Wisconsin- Madison

Ji Hee Yoon, University College London

Exchange Design and Efficiency

1:30 pm

Open Discussions

2:00 pm

Martin Bichler, Technical University of Munich

Maximilian Fichtl, Technical University of Munich

Stefan Heidekrüger, Technical University of Munich

Nils Kohring, Technical University of Munich

Paul Sutterer, Technical University of Munich

Learning to Bid: Computing Bayesian Nash Equilibrium Strategies in Auctions via Neural Pseudogradient Ascent

2:45 pm

Mohammad Akbarpour, Stanford University

Scott Duke Kominers, Harvard University

Shengwu Li, Harvard University

Paul Milgrom, Stanford University

Investment Incentives in Near-Optimal Mechanisms

3:30 pm

Open Discussions

4:00 pm

Adjourn

Job matching under constraints by Kojima, Sun, and Yu in the September AER

 From the September AER, the latest in a distinguished string of papers initially motivated by aspects of the clearinghouse for new doctors in Japan:

Kojima, Fuhito, Ning Sun, and Ning Neil Yu. 2020. "Job Matching under Constraints." American Economic Review, 110 (9): 2935-47.  DOI: 10.1257/aer.20190780

Abstract: Studying job matching in a Kelso-Crawford framework, we consider arbitrary constraints imposed on sets of doctors that a hospital can hire. We characterize all constraints that preserve the substitutes condition (for all revenue functions that satisfy the substitutes condition), a critical condition on hospitals' revenue functions for well-behaved competitive equilibria. A constraint preserves the substitutes condition if and only if it is a "generalized interval constraint," which specifies the minimum and maximum numbers of hired doctors, forces some hires, and forbids others. Additionally, "generalized polyhedral constraints" are precisely those that preserve the substitutes condition for all "group separable" revenue functions.

Here's the first paragraph:

"Hiring entities often face various types of constraints. In the United States, firms that receive favorable treatments from governments often promise to hire at least a certain number of workers (Byrnes, Marvel, and Sridhar 1999): floor constraints. In Chinese cities, the household registration system distributes quotas to employers for transferring  employees’ registrations from other places (Chan and Zhang 1999): type-specific ceiling constraints on hiring nonlocals. In rural India, a health subcenter is often required to be staffed by exactly one male and one female (Kapoor 2011): type-specific constraints with exact quotas. These are restrictions on the set of employees that an employer is allowed to hire. Inspired by a classical framework for studying job markets (Kelso and Crawford 1982), this paper studies how all possible restrictions of this type impact the substitutes condition on revenue functions of the employers, a condition known to be critical for the existence and certain regularity properties of competitive equilibria (Kelso and Crawford 1982; Gul and Stacchetti 1999; Milgrom 2000; Hatfield et al. 2019; Kojima, Sun, and Yu 2020a)"

and, from the Conclusions section:

"In a classical paper on the difficulty for rural hospitals in filling all of their positions in the National Resident Matching Program, Roth (1986) concludes that “this maldistribution seems unlikely to be changed by any system that does not involve some element of compulsion, or some change in the relative numbers of available positions and eligible students.” Our analysis suggests that in job matching with adjustable salaries, a compulsion in the form of floor or ceiling constraints may be a possible solution: one of the appealing properties of such a policy is that it preserves the substitutes condition and thus the existence of competitive equilibria under standard assumptions (Kojima, Sun, and Yu 2020a)."

On allocating scarce vaccines

 From the NBER working papers this week:

Do Black and Indigenous Communities Receive their Fair Share of Vaccines Under the 2018 CDC Guidelines?

Parag A. Pathak, Harald Schmidt, Adam Solomon, Edwin Song, Tayfun Sönmez, M. Utku Ünver

NBER Working Paper No. 27817   September 2020

Abstract: A major focus of debate about rationing guidelines for COVID-19 vaccines is whether and how to prioritize access for minority populations that have been particularly affected by the pandemic, and been the subject of historical and structural disadvantage, particularly Black and Indigenous individuals. We simulate the 2018 CDC Vaccine Allocation guidelines using data from the American Community Survey under different assumptions on total vaccine supply. Black and Indigenous individuals combined receive a higher share of vaccines compared to their population share for all assumptions on total vaccine supply. However, their vaccine share under the 2018 CDC guidelines is considerably lower than their share of COVID-19 deaths and age-adjusted deaths. We then simulate one method to incorporate disadvantage in vaccine allocation via a reserve system. In a reserve system, units are placed into categories and units reserved for a category give preferential treatment to individuals from that category. Using the Area Deprivation Index (ADI) as a proxy for disadvantage, we show that a 40% high-ADI reserve increases the number of vaccines allocated to Black or Indigenous individuals, with a share that approaches their COVID-19 death share when there are about 75 million units. Our findings illustrate that whether an allocation is equitable depends crucially on the benchmark and highlight the importance of considering the expected distribution of outcomes from implementing vaccine allocation guidelines.

Covid has slowed transplants in the UK

The Evening Standard has the story:

Organ transplant waiting list jumps to five-year high due to pandemic, new NHS figures show

by Naomi Ackerman 

"The number people waiting for an organ transplant has soared to five-year high as a result of the coronavirus pandemic, new NHS figures have shown.

"NHS Blood and Transplant (NHSBT) said this week that an estimated 6,700 people are currently in need of a transplant across the UK - up from 6,138 prior to the start of the pandemic.

"The health body has estimated that the increase in patients waiting - expected to be the highest since 2015-16 - comes after services were impacted by the effects of the pandemic.

...

"It is hoped that the waiting list can be shortened going forward following the introduction of a new law in May, making organ donation "opt-out" rather than an active choice.

...

"The law will see that families are still consulted before organ donation goes ahead - the reason is why health officials have implored people to make their wishes about donation known to their families.

"NHSBT has said that thousands of "transplant opportunities" have been missed in recent years. In 2018-19, it reported that 835 families declined to support organ donation - with many families saying they did not know what their relative would have wanted."

***********

HT: Alex Chan

Economies in the Time of Coronavirus (in English and Chinese)

 Here's a short essay I wrote for the Luhohan Academy in June, published on their web site in July in English, and the Chinese translation in the Caixin online magazine.

Economies in the Time of Coronavirus

by Alvin E. Roth

Here's the first paragraph:

"Years from now we will look back on the Covid-19 pandemic as a source of much new information, not just about epidemic disease and how to manage it, but about structural features of the world’s economies that were made clearer by the crisis and how it was handled, both well and badly.  In the meantime, we can begin to speculate about what we will have learned when the pandemic is history, and what we must still learn to prepare for dealing with its continuation, and with future pandemics."

...

here's another paragraph:

"Testing policies will have to keep in mind what economists know well, which is that there may be perverse incentives in play. Some people will be very eager to return to work, and might be willing to do so even when they risk spreading infection. Others may be happy to work from home (especially if there is risk of infection at work) and may not wish to return to work even when they themselves do not pose a risk to others. And if those who have been infected and have recovered  (e.g. who test positive for antibodies) are treated differently than others, some people may feel a need to expose themselves to infection in order to enter this privileged class. So who conducts the tests, and how they are reported and recorded, will be important."

and here it begins in Chinese (but gated):

阿尔文·罗思：新冠疫情时期的经济与政策 

2020年07月17日 10:59

T中

为应对疫情，我们要完成一些当下和短期目标，而为下一次大流行病做准备，我们面临一些更长期的任务

　　文|阿尔文·罗思（Alvin E. Roth）

　　 

A proposal for non-simultaneous kidney exchange in pairs and chains and with deceased donors...

 Here's an ambitious proposal, that may face  obstacles to implementation, but which provides some clarity about the inefficiencies of current practice.

Unpaired Kidney Exchange: Overcoming Double Coincidence of Wants without Money

Mohammad Akbarpour, Julien Combe, Yinghua He, Victor Hiller, Robert Shimer, Olivier Tercieux

NBER Working Paper No. 27765, September 2020, pdf

Abstract: For an incompatible patient-donor pair, kidney exchanges often forbid receipt-before-donation (the patient receives a kidney before the donor donates) and donation-before-receipt, causing a double-coincidence-of-wants problem. Our proposed algorithm, the Unpaired kidney exchange algorithm, uses “memory” as a medium of exchange to eliminate these timing constraints. In a dynamic matching model, we prove that Unpaired delivers a waiting time of patients close to optimal and substantially shorter than currently utilized state-of-the-art algorithms. Using a rich administrative dataset from France, we show that Unpaired achieves a match rate of 57 percent and an average waiting time of 440 days. The (infeasible) optimal algorithm is only slightly better (58 percent and 425 days); state-of-the-art algorithms deliver less than 34 percent and more than 695 days. We draw similar conclusions from the simulations of two large U.S. platforms. Lastly, we propose a range of solutions that can address the potential practical concerns of Unpaired.

Politics and medicine, at Stanford and in Washington--an open letter from Stanford docs about corona virus policies

 Politics and medicine can combine poorly, particularly in a politicized pandemic.

Here's an open letter from over a hundred faculty at Stanford's Medical school, disowning the positions about pandemic policies taken by one of their former colleagues, now in Washington, by way of Fox News. (Here's the letter in full; to see the signatories click on the link...)

An Open Letter from Stanford Doctors [Update: the letter has been taken down from the Stanford medicine website, but here is another copy...]

"As infectious diseases physicians and researchers, microbiologists and immunologists, epidemiologists and health policy leaders, we stand united in efforts to develop and promote science-based solutions that advance human health and prevent suffering from the coronavirus pandemic. In this pursuit, we share a commitment to a basic principle derived from the Hippocratic Oath: Primum Non Nocere (First, Do No Harm).

"To prevent harm to the public’s health, we also have both a moral and an ethical responsibility to call attention to the falsehoods and misrepresentations of science recently fostered by Dr. Scott Atlas, a former Stanford Medical School colleague and current senior fellow at the Hoover Institute at Stanford University. Many of his opinions and statements run counter to established science and, by doing so, undermine public-health authorities and the credible science that guides effective public health policy. The preponderance of data, accrued from around the world, currently supports each of the following statements:

●  The use of face masks, social distancing, handwashing and hygiene have been shown to substantially reduce the spread of Covid-19. Crowded indoor spaces are settings that significantly increase the risk of community spread of SARS-CoV-2.

●  Transmission of SARS-CoV-2 frequently occurs from asymptomatic people, including children and young adults, to family members and others. Therefore, testing asymptomatic individuals, especially those with probable Covid-19 exposure is important to break the chain of ongoing transmission.

●  Children of all ages can be infected with SARS-CoV-2. While infection is less common in children than in adults, serious short-term and long-term consequences of Covid-19 are increasingly described in children and young people.

●  The pandemic will be controlled when a large proportion of a population has developed immunity (referred to as herd immunity) and that the safest path to herd immunity is through deployment of rigorously evaluated, effective vaccines that have been approved by regulatory agencies.

●  In contrast, encouraging herd immunity through unchecked community transmission is not a safe public health strategy. In fact, this approach would do the opposite, causing a significant increase in preventable cases, suffering and deaths, especially among vulnerable populations, such as older individuals and essential workers.

"Commitment to science-based decision-making is a fundamental obligation of public health policy. The rates of SARS-CoV-2 infection in the US, with consequent morbidity and mortality, are among the highest in the world. The policy response to this pandemic must reinforce the science, including that evidence-based prevention and the safe development, testing and delivery of efficacious therapies and preventive measures, including vaccines, represent the safest path forward. Failure to follow the science -- or deliberately misrepresenting the science – will lead to immense avoidable harm.

"We believe that social and economic activity can reopen safely, if we follow policies that are consistent with science. In fact, the countries that have reopened businesses and schools safely are those that have implemented the science-based strategies outlined above.

"As Stanford faculty with expertise in infectious diseases, epidemiology and health policy, our signatures support this statement with the hope that our voices affirm scientific, medical and public health approaches that promote the safety of our communities and nation."

*******

Here's a recent NY Times story on Dr. Atlas, a radiologist:

A New Coronavirus Adviser Roils the White House With Unorthodox Ideas

Dr. Scott Atlas arrived at the White House as a coronavirus contrarian, questioning controls like masks. He has angered top health officials while pushing a suite of disputed policy prescriptions.

By Noah Weiland, Sheryl Gay Stolberg, Michael D. Shear and Jim Tankersley,  Sept. 2, 2020

"Before joining the task force, Dr. Atlas pitched his ideas as a health commentator on Fox News, which is in part how he attracted Mr. Trump’s attention. His arrival at the White House has coincided with less visible roles for Dr. Birx and Dr. Fauci, the director of the National Institute for Allergy and Infectious Diseases."

**********

Of course, medicine isn't the only kind of science that has been caught up in Washington lately. (I write this from smoky California, where climate change seems quite real).

Nor is it the only part of medicine that has been caught up in politics around the world: I'm reminded of yesterday's post about the politics of global health care.  Science seems to be slowly gaining on politics there, and so I'm hopeful that's a general trend, although sometimes slow and uneven, with a high ratio of heat to light.

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

Quite some time ago, the European Society for Organ Transplantation (ESOT) charged its committee on Ethical, Legal, and Psychosocial Aspects of Transplantation (ELPAT) with the task of evaluating those aspects of global kidney exchange (GKE). GKE had been greeted in some quarters with a number of dramatic accusations (e.g. that it was a form of organ trafficking), and the ELPAT committee tried to consider each of them.  Interestingly, the committee included members who I surmise started with a wide range of views, from cautious support to active hostility to GKE.

The final report, just published in Transplant International,  (which is the official journal of ESOT) is one that I think the committee can be proud of.  While you can tell that some committee members retain reservations about GKE, they nevertheless all agreed on a report that finds all of the principal objections raised against GKE to be unfounded.  Together with the even more clearly stated support for GKE in the Lancet, I think that this may mark a turning point: it certainly marks that GKE is receiving growing (and well deserved) support. 

Global Kidney Exchange: opportunity or exploitation? An ELPAT/ESOT appraisal
Frederike Ambagtsheer  Bernadette Haase‐Kromwijk  Frank J. M. F. Dor  Greg Moorlock  Franco Citterio  Thierry Berney  Emma K. Massey
Transplant International, September 2020, 33, 9, 989-998.    

https://onlinelibrary.wiley.com/doi/full/10.1111/tri.13630       Here's the pdf

"Summary: This paper addresses ethical, legal, and psychosocial aspects of Global Kidney Exchange (GKE). Concerns have been raised that GKE violates the nonpayment principle, exploits donors in low‐ and middle‐income countries, and detracts from the aim of self‐sufficiency. We review the arguments for and against GKE. We argue that while some concerns about GKE are justified based on the available evidence, others are speculative and do not apply exclusively to GKE but to living donation more generally. We posit that concerns can be mitigated by implementing safeguards, by developing minimum quality criteria and by establishing an international committee that independently monitors and evaluates GKE’s procedures and outcomes. Several questions remain however that warrant further clarification. What are the experiences and views of recipients and donors participating in GKE? Who manages the escrow funds that have been put in place for donor and recipients? What procedures and safeguards have been put in place to prevent corruption of these funds? What are the inclusion criteria for participating GKE centers? GKE provides opportunity to promote access to donation and transplantation but can only be conducted with the appropriate safeguards. Patients’ and donors’ voices are missing in this debate." 

Here's their introduction:

"In 2017, Rees et al. [1] introduced “Global Kidney Exchange” (GKE), an international kidney exchange program that facilitates cross‐border exchanges between immunologically incompatible donor–recipient pairs in high‐income countries (HIC) and biologically compatible but financially impoverished donor–recipient pairs in low‐ to middle‐income countries (LMIC). GKE aims to overcome immunologic barriers in the developed world and poverty barriers in the developing world. The underlying rationale is that financial barriers prevent transplantation much more frequently than organ scarcity. The number of patients dying annually worldwide from end‐stage kidney disease due to inadequate financial resources far exceeds the number of patients in developed countries placed on kidney transplantation waitlists [1-3]. GKE has the potential to expand the genetic diversity of the donor pool which may help to transplant difficult‐to‐transplant, highly immunized patients [1]."

As they debunk the main arguments that have been made against GKE, I thought that some of these remarks were among the most interesting:

"Removing financial barriers to organ donation is an internationally agreed objective, enshrined, among others, in the World Health Organization’s (WHO) Guiding Principles on Human Cell, Tissue and Organ Transplantation and in the CoE Convention [13, 15]. These organizations highlight that prohibition of organ payments does not preclude reimbursing expenses incurred by the donor, including the costs of medical procedures [13, 17]. Given that countries’ legislation vary in their approach to what constitutes illicit payment versus legitimate reimbursement, it is doubtful whether GKE violates the nonpayment principle under all circumstances. For example, the University of Minnesota’s legal team vetted GKE and agreed to proceed. Other hospital legal teams have followed suit [1]."

...

"“[e]xploitation occurs when someone takes advantage of a vulnerability in another person for their own benefit, creating a disparity in the benefits gained by the two parties” [9]. It is hard to see, however, that this description of exploitation can be readily applied to GKE. Primarily, it is not clear that there is a significant disparity in benefits between recipients. Each patient receives a kidney transplant, and as Minerva et al point out, benefits are arguably greater for LMIC recipients, who get the additional benefit of their follow‐up care being paid for [33]. The same is true for the donors, who each obtain the desired benefit of their intended beneficiary receiving a transplant. Rather than there being a morally troubling disparity in benefit, GKE appears to offer either roughly equal benefit, or greater benefit for those who are allegedly exploited."

"It is also unconvincing to consider GKE exploitative on other grounds. Rather than failing to protect the vulnerable, it seems that GKE addresses specific vulnerabilities by offering protection to those who are (i) vulnerable to death from kidney failure or (ii) vulnerable to losing a loved one due to kidney failure. It is similarly unconvincing to suggest that GKE treats people merely as a means to an end. Instead, one can see that participants in LMIC are respected as individuals, with measures put in place to protect their welfare and to ensure that their participation is voluntary."

...

The claim that donors and recipients in LMIC are too poor or vulnerable to voluntarily engage in GKE is also debatable and could be seen as paternalistic. First of all, the risk that voluntariness is undermined does not apply specifically to GKE or to LMIC alone, but applies to living donation more generally [35].

...

"The proclamation that countries have to be self‐sufficient was first declared by the 2008 DoI and the WHO [73, 74] and has rapidly gained momentum since [75-77]. The argument to ban GKE because of the need to achieve self‐sufficiency raises various implications however. First of all, it implies that the need for countries to become self‐sufficient is more important than the lives that can be immediately saved through GKE. Is achievement of self‐sufficiency so important that it overrides life‐saving alternatives? Who has the authority to decide which approach should get priority? Why is it required that countries become self‐sufficient in organ donation and transplantation, while it is universally accepted for countries to rely on global exchanges of all other types of goods and services?

 ***********************

The ESOT/ELPAT committee apparently operated under rules that prevented them from investigating some claims that required evidence, so they included some questions for us in their paper, which we answer in the comment that appeared in the same issue of TI. (For example, there was some confusion about what escrow meant in connection with the money provided for the foreign donor and recipient's medical expenses after their return home...)

In any event, the large number of co-authors to our comment (21!) is another expression of the broad and international support that GKE is achieving.

Global Kidney Exchange Should Expand Wisely
Alvin E. Roth  Ignazio R. Marino  Obi Ekwenna  Ty B. Dunn  Siegfredo R. Paloyo  Miguel Tan  Ricardo Correa‐Rotter  Christian S. Kuhr  Christopher L. Marsh  Jorge Ortiz  Giuliano Testa  Puneet Sindhwani  Dorry L. Segev  Jeffrey Rogers  Jeffrey D. Punch  Rachel C. Forbes  Michael A. Zimmerman  Matthew J. Ellis  Aparna Rege  Laura Basagoitia  Kimberly D. Krawiec  Michael A. Rees 

Transplant International, September 2020, 33, 9,  985-988. https://onlinelibrary.wiley.com/doi/full/10.1111/tri.13656   Here's a link to the pdf 

Here's the full first paragraph:

"We read with great interest and appreciation the careful consideration and analysis by Ambagtsheer et al. of the most critical ethical objections to Global Kidney Exchange (GKE). Ambagtsheer et al. conclude that implementation of GKE is a means to increase access to transplantation ethically and effectively.1,2 These conclusions by their European Society of Transplantation (ESOT) committee on Ethical, Legal and Psychological Aspects of Transplantation (ELPAT) represent a step forward toward a greater understanding and an open, honest debate about GKE. Taken together with the strong endorsement of GKE by Minerva et al. in Lancet  and the positive position statement of the American Society of Transplant Surgeons (ASTS), Ambagtsheer et al. successfully dispel previously raised doubts 5-13 to which we have previously responded .2,14-17"

************

Here are all my posts on global kidney exchange (GKE)

Plasma in Canada, and repugnant transactions--a podcast interview

 I was recently interviewed by Kate van der Meer, a Canadian patient affected by the plasma shortage of 2019. Her experience inspired her to look deeper into the plasma supply chain and raise awareness to the negative implications of the Voluntary Blood Donations Act. Part of this awareness campaign is the Plasma For Life Podcast Series, of which this interview is a part. 

(Her website is  www.plasmaforlife.org.)

.

Fuhito Kojima wins the 2021 Japanese Economic Association Nakahara Prize

 Congratulations to Fuhito Kojima, who is the 2021 winner of the Nakahara Prize of the Japanese Economic Association, which is awarded each year to an exceptional economist under the age of 45.

You can find the announcement (in Japanese) here. Google translate works well, and you can see the list of previous winners.

Here's part of the English announcement (which I can't find on the web...)

"The 2021 Japanese Economic Association Nakahara Prize

Professor Fuhito Kojima

"The Nakahara prize was established in 1995 and is funded by a donation from Mr. Nobuyuki Nakahara. The aim of the prize is to honor and encourage young researchers under the age of 45 to publish internationally recognized research. 

It is a great pleasure to announce that the 2021 Nakahara prize has been awarded to Professor Fuhito Kojima. Born in 1979, Professor Kojima received BA in economics from the University of Tokyo, and earned Ph.D. in economics from Harvard University in 2008. He was Assistant, Associate and then Full Professor of Economics at Stanford University, and he is Professor of Economics at the University of Tokyo from September 2020.

Professor Kojima’s research is focused on matching theory and market design. He has made a number of important contributions to the field. Many of his researches are motivated by various kinds of constraints imposed on matching problems in real life. His research significantly contributes to widening applicability of the theory to real matching markets.

...

"Selected Publications

1. “Job Matching under Constraints” (2020), joint with Ning Sun and Ning Neil Yu,  conditionally accepted, American Economic Review.

2. “Stable Matching in Large Economies” (2019), with Yeon-Koo Che and Jinwoo Kim, Econometrica, 87-1, pp65-110.

3. “Efficient Matching Under Distributional Constraints: Theory and Applications” (2015), with Yuichiro Kamada, American Economic Review, 105, pp 67-99.

4. “Matching with Couples: Stability and Incentives in Large Matching Markets” (2013), with Parag A. Pathak and Alvin E. Roth, Quarterly Journal of Economics 128, pp 1585-1632.

5. “Designing Random Allocation Mechanisms: Theory and Applications” (2013), with Eric Budish, Yeon-Koo Che, and Paul Milgrom, American Economic Review 103, pp 585-623.

6. “Asymptotic Equivalence of Probabilistic Serial and Random Priority Mechanisms” (2010), with Yeon-Koo Che, Econometrica 78, pp 1625-1672.

7. “Axioms for Deferred Acceptance” (2010), with Mihai Manea, Econometrica 78, pp 633-653.

8. “Incentives and Stability in Large Two-Sided Matching Markets” (2009), with Parag A. Pathak, American Economic Review 99, pp 608-27.

SELECTION COMMITTEE

Kosuke Aoki (Chair) (University of Tokyo), Anton Braun (Federal Reserve Bank of Atlanta), Federico Echenique (California Institute of Technology), Yuichi Kitamura (Yale University), Fumio Ohtake (Osaka University), Tadashi Sekiguchi (Kyoto University), Mototsugu Shintani (University of Tokyo)

************

By a strange coincidence,  in 2013 I was the recipient of a non-academic award signed by Mr. Nobuyuki Nakahara, whose interests extend beyond economics.

Child marriage in Somalia

 The Guardian has the story:

'A race against time': the new law putting Somalia's children at risk of marriage: Child marriage in the country has increased during coronavirus – and now a newly-tabled bill would allow children as young as 10 to marry   by Moulid Hujale

"According to the latest government figures, 34% of Somali girls are married before they reach 18, and 16% of them before their 15th birthday.

"While children are married off for different reasons, such as the economic benefit of a dowry, and an increase in child marriage cases has been reported during the coronavirus pandemic, early marriage is rooted in Somali culture. An old Somali saying goes: “Gabadh ama god hakaaga jirto ama gunti rag,” which loosely translates as “a girl should either be married or in a grave”.

"Marriage under 18 is not illegal, although Somalia’s constitution prohibits it and the country is signed up to several international treaties promising to tackle it. In July 2014, the government signed a charter committing to end child marriage by 2020. But in August, the Somali parliament tabled a controversial bill that would allow a child to be married once they reached puberty, which can mean 10 years old. The sexual intercourse related crimes bill would also allow marriage if parents consented. The UN has called the bill “deeply flawed”.

Human infection (challenge) trials for a covid-19 vaccine--Reason magazine interviews Josh Morrison (video)

 Reason magazine has a video story about human challenge trials, starring Josh Morrison, the founder of 1Day Sooner.  I make some comments as well.

 

 You can also find the video at reason.com here (along with a partial transcript), and on YouTube here.

**************

See all my posts on vaccines here.

Transplant transport: direct commercial flights boost deceased donor transplants, by Wang, Zheng, and Dai

 Alex Chan draws my attention to this paper on airline transport of kidneys for transplant:

Does Transportation Mean Transplantation? Impact of New Airline Routes on Sharing of Cadaveric Kidneys

38 Pages Posted: 6 May 2020

Guihua Wang

University of Texas at Dallas - Naveen Jindal School of Management

Ronghuo Zheng

University of Texas at Austin - McCombs School of Business

Tinglong Dai

Johns Hopkins University - Carey Business School

 

Abstract

Nearly 5,000 patients die every year while waiting for kidney transplants, and an estimated 18% of procured kidneys are discarded. Such a polarized co-existence of dire scarcity and massive wastefulness has been mainly driven by insufficient pooling of cadaveric kidneys across geographic regions. Although numerous policy initiatives are aimed at broadening organ pooling, they rarely account for a key friction — efficient airline transportation, ideally direct flights, is necessary for long-distance sharing due to the time-sensitive nature of kidney transplantation. Conceivably, transplant centers may be reluctant to accept kidney offers from far-off locations without direct flights. In this paper, we estimate the effect of the introduction of new airline routes on broader kidney sharing. By merging the U.S. airline transportation and kidney transplantation datasets, we create a unique sample tracking (1) the evolution of airline routes connecting all the U.S. airports and (2) kidney transplants between donors and recipients connected by these airports. We estimate the introduction of a new airline route increases the number of shared kidneys by 7.3%. We also find a net increase in the total number of kidney transplants with the introduction of new routes. Notably, the post-transplant survival rate remains largely unchanged, though average travel distance increases after the introduction of new airline routes. Our results are robust to alternative empirical specifications and have important implications for improving access to the U.S. organ transplantation system.

Taboo Trades: a new podcast by Kim Krawiec

 Who better to talk about forbidden markets than Kim Krawiec?  Her new podcast is off to a great start.

Taboo Trades

Kimberly D Krawiec

"A podcast about things we aren’t supposed to trade . . . But do anyway"

Recent Episodes

Kidneys and Challenge Trials with Josh MorrisonSEPTEMBER 01, 2020Plasma with Peter JaworskiAUGUST 25, 2020

Paul Milgrom celebrates his 100,000th Google cite

 100,000 and counting.

Paul Milgrom on Google Scholar

The Alliance for Paired Kidney Donation has announced its Donor Protection Program

The Alliance for Paired Kidney Donation has announced the details of its Donor Protection Program

"The APKD protects a donor’s finances & family at no cost to transplant centers.

• Lost wage and travel expense reimbursement
• Life, disability, and complication insurance
• A future kidney if needed: The APKD KidneyPledge"

Peter Cramton on the retail electricity market in California

 Peter Cramton* is an astute observer of electricity markets.  Here's his op-ed in the San Diego Union-Tribune:

Commentary: My monthly electric bill in Texas would be $250. In California, it is $1,000. Here’s why.

Here's the first paragraph:

"Rolling outages may appear to be a symptom of climate change. Extreme heat and intermittent renewables certainly challenge electricity markets. But these challenges can be met with good market design. The California market has flaws that make California electricity more expensive and less reliable than it should be. Fixing these flaws should be a priority."

and here's the final paragraph:

"California illustrates that good intentions do not necessarily produce good policy. Good policy is designed from what we know about markets and human behavior. Good policy is the only way to provide reliable electricity at least cost"

*"Cramton is a professor of economics at the University of Cologne and the University of Maryland, is an independent board member of ERCOT, the electricity operator in Texas. The views here are his own and not those of ERCOT or ERCOT’s board."

Who Gets In, and Why--an inside look at college admissions

Here's an essay from the WSJ, adapted from a forthcoming book with an evocative title, “Who Gets In and Why, by Jeffrey Selingo. The subtitle is A Year Inside College Admissions

The Secrets of Elite College Admissions: In the final ‘shaping’ of an incoming class, academic standards give way to other, more ambiguous factors by By Jeffrey Selingo, Aug. 28, 2020

"The year I was inside Emory University’s admissions office, the school received a record 30,000 applications for fewer than 1,400 spots in its incoming class. In early March, just weeks before official notices were scheduled to go out, the statistical models used by Emory to predict enrollment indicated that too many applicants had been chosen to receive acceptances. In the span of days, teams of admissions officers covering five geographical areas had to shift 1,000 applications from the thin “admit” stack to the much larger “deny” or “wait list” piles.

Matching inequality and strategic behavior under the Boston mechanism: Evidence from China's college admissions by Wu and Zhong

 Here's a paper that analyses the immediate acceptance ("Boston") algorithm that was in use in China's college admissions system in many provinces, in 2003.

Matching inequality and strategic behavior under the Boston mechanism: Evidence from China's college admissions

by BinzhenWu and Xiaohan Zhong

Games and Economic Behavior, Volume 123, September 2020, Pages 1-21,  https://doi.org/10.1016/j.geb.2020.05.007

Abstract: We examine matching inequality in students' matching outcomes for the Boston Mechanism in a large matching system, by measuring the degree of mismatch for each student. We link a student's mismatch with her reporting behavior of the first choice on her preference list to explore the reasons for matching inequality. Using administrative data from college admissions in China, we find significant gender differences, rural-urban gaps, and ethnic gaps in mismatching and first-choice behavior. These demographic differences exhibit various patterns and may be explained by risk aversion, information disadvantage, and minority-preferential admissions policies, respectively.

The econometrics of deceased kidney donation

Two papers have made me think about the power of econometric methods applied to studies of medical issues related to matching deceased donor kidneys to patients.

I recently heard Chuck Manski give a seminar on this paper published last year in PNAS:

One thing I took away from it is that proportional hazard (Cox) models are very popular in the medical literature, but they assume that effects (e.g. rejection of a graft) are proportional to time, and there are immunological processes that don't in fact have a constant hazard rate, but build up over time, so that isn't a good model for those things.

Predicting kidney transplant outcomes with partial knowledge of HLA mismatch

Charles F. Manski,  Anat R. Tambur, and Michael Gmeiner, PNAS October 8, 2019 116 (41) 20339-20345

"Abstract: We consider prediction of graft survival when a kidney from a deceased donor is transplanted into a recipient, with a focus on the variation of survival with degree of human leukocyte antigen (HLA) mismatch. Previous studies have used data from the Scientific Registry of Transplant Recipients (SRTR) to predict survival conditional on partial characterization of HLA mismatch. Whereas earlier studies assumed proportional hazards models, we used nonparametric regression methods. These do not make the unrealistic assumption that relative risks are invariant as a function of time since transplant, and hence should be more accurate. To refine the predictions possible with partial knowledge of HLA mismatch, it has been suggested that HaploStats statistics on the frequencies of haplotypes within specified ethnic/national populations be used to impute complete HLA types. We counsel against this, showing that it cannot improve predictions on average and sometimes yields suboptimal transplant decisions. We show that the HaploStats frequency statistics are nevertheless useful when combined appropriately with the SRTR data. Analysis of the ecological inference problem shows that informative bounds on graft survival probabilities conditional on refined HLA typing are achievable by combining SRTR and HaploStats data with immunological knowledge of the relative effects of mismatch at different HLA loci."

************

And here's a recent working paper that says that if we want to maximize life years added by transplant, more organs should go more quickly to healthier patients:

Choices and Outcomes in Assignment Mechanisms: The Allocation of Deceased Donor Kidneys

Nikhil Agarwal, Charles Hodgson, Paulo Somaini, August 17, 2020

"Abstract: While the mechanism design paradigm emphasizes notions of efficiency based on agent preferences, policymakers often focus on alternative objectives. School districts emphasize educational achievement; and transplantation communities focus on patient survival. However, it is unclear whether choice-based mechanisms perform well when assessed using these outcomes. This paper evaluates the assignment mechanism for allocating deceased donor kidneys on the basis of the additional patient life-years from transplantion (LYFT). We examine the role of choice in increasing LYFT and compare equilibrium assignments to benchmarks that remove choice. Our approach combines a model of choice and outcomes in order to study how selection induced in the mechanism produces the outcome of

interest, LYFT. We show how to identify and estimate the model using quasi-experimental variation resulting from the mechanism. The estimates suggest that the design in use selects patients with better survival prospects after a transplant and matches them well. It results in an average LYFT of 7.97, which is 0.88 years higher than a random assignment. However, there is scope for increasing the aggregate LYFT to 12.07. While some of this increase can be achieved by assigning transplanted patients to different donors, realizing the majority requires transplanting relatively healthy patients, who would have longer life-expectancy even without a transplant. Therefore, a policymaker faces a dilemma between transplanting patients that are sicker and those for whom life will be extended the longest."