Friday, June 30, 2023

Lloyd Shapley (1923-2016) Centennial

 Lloyd Harlow Shapley was born in 1923: he would be (and I guess is) 100 years old this year.  His family is assembling a website honoring his centennial. (It's part of a family of web pages devoted to the life and work of Lloyd's dad, the astronomer Harlow Shapley.)

Here's the page for the Lloyd Shapley Centennial

It appears to be a work in progress, with many links. It begins this way:

"Lloyd Shapley (1923-2016) was a Nobel prizewinning mathematician. Shapley’s "intellectual life and career ... was among the most fertile of the 20th century." For the Centennial of Lloyd’s birth the Harlow Shapley Project offers this easy-access guide to Lloyd's WORK, his favorite GAME Kriegspiel, personal STORIES not published before and his four PRIZES.

"Lloyd Shapley was one of the founding giants of game theory. He shared the 2012 Nobel Prize in Economics for his seminal work with the late David Gale on stable matching – situations in which there are no two agents who would prefer one another over their current counterparts. But "he could have won a Nobel for any of a number of his papers that initiated whole literatures,” wrote Alvin E. Roth, Lloyd’s Nobel co-winner (right).

"Mathematical giant John von Neumann (right) invited Lloyd to leave RAND for Princeton on the basis of a two-page paper Lloyd sent him. After getting his Princeton PhD Lloyd returned to RAND full-time. He was a very productive member of the fabled Mathematics Division. Lloyd was almost unbeatable in the Division’s lunchtime Kriegspiel matches. 

"The Work page has summaries of Lloyd’s main contributions prepared by Dr. Bruce E. Krell, a game theorist who was a colleague of Lloyd’s at RAND. The Work page also offers a bibliography of selected descriptions of his work. The Work includes the 1962 “marriage problem” paper with David Gale (right), which won the Nobel."

Thursday, June 29, 2023

Kidney Exchange in Hong Kong

While liver exchanges have been done for some time in Hong Kong, possibly the first kidney exchange  has recently been reported by China Daily:

Exchanging the hope of life By Li Bingcun | HK EDITION |  2023-06-16 

"It was the first time that paired kidney transplants had been carried out in the city. Following a pilot program launched in 2018, if a patient's family member is willing to donate a kidney to the patient but their conditions do not match, the family is allowed to make a cross-donation with another family in the same situation. Previously, organ donations from living donors could be made only by close blood relatives and spouses.

"In addition to kidney transfers, Hong Kong has accomplished several cross-family liver transplants since 2009 with special approvals made by the Human Organ Transplant Board on a case-by-case basis. Facing a severe shortage of organ donations, Hong Kong is drawing on overseas experiences to widen the scope of donations from living donors by trying to overcome restrictions concerning blood type and marriage, seeking greater matching possibilities to achieve more life-saving miracles.

"These attempts involve considerable efforts to update traditional mindsets, address the accompanying ethical and legal issues, and protect the safety and interests of donors and recipients to the fullest extent.

However, because of risks to donors, medical experts suggest that organ donations from living people should never be the first choice, and that the priority should be boosting people's willingness to register as organ donors, allowing organs to be reused after registered people die.

"Globally, such kidney exchange programs have been introduced in South Korea, the United States, the United Kingdom, Australia and Canada, with surgeries performed two decades ago.

"Besides paired donations, the US also allows "nondirected donations", which means a donor can donate his or her kidney to any compatible patient. The largest kidney swaps were completed in 2014, involving 70 participants. Some global exchange programs have also carried out transnational kidney donations.

"With Hong Kong's relatively low organ-donation rate, more than 2,000 local residents are awaiting kidney transplants each year, with an average waiting time of about five years, and the longest 29 years. The number of kidney donations from living family members is less than 20 annually, while the number of cadaveric donations declined from 84 in 2012 to 45 in 2022.

"Although renal-failure patients can receive dialysis to sustain their lives, organ transplantation is still the best option. Moreover, the quality of organs of living donors is considered better than that of cadaveric organs.

"To offer patients another option, Hong Kong had been preparing to introduce the paired kidney donation (PKD) program since 2012, according to Chau Ka-foon, former co-chairperson of the Hospital Authority's Paired Kidney Donation Working Group. After extensive discussions, the city revised the law in 2018 and officially launched the program.


"two families that were successfully matched in 2020 canceled their planned surgeries due to personal concerns. Chau explains that the families might have worried that the organ received was of lower quality than the one they donated. It would also be a heavy blow if a family donating a kidney were unable to receive one if an operation were to fail.


"Attempts to swap organs among strangers have also encountered complex legal and technical problems.

"In Hong Kong's first-ever cross-family transplant in 2009, the medical team made a lot of efforts explaining to the Human Organ Transplant Board that the operation wasn't a transaction. "We repeatedly emphasized that the two families did not intend to exchange organs. It was simply the medical workers' proposal to raise the success rate of organ transplants," says Lo Chung-mau, chief surgeon of the operation and also director of the liver transplantation center at Queen Mary Hospital at that time.


"The 2019 social unrest and the following COVID-19 pandemic presented even greater challenges for Hong Kong's PKD program. In 2021, there were 26 eligible families in the city's organ matching pool.

"The Hospital Authority expects the number of participating families to climb to 50 to 100 in a few years. It will consider expanding the program to liver donations and collaborating with overseas matching pools. Chau hopes that kidney swaps will not be limited to just two families, and that multiple swaps among several families will be allowed to increase the chances of matching.


"Wang Haibo, a member of China's National Organ Donation and Transplantation Committee, says the pair-donation program is worth looking into and being discussed. The mainland is also conducting clinical research on paired-kidney donations. Alvin Roth, who won the 2012 Nobel Memorial Prize in Economic Sciences and developed a global kidney-exchange program, visited China before the COVID-19 pandemic to seek collaboration in this area, he recalls.

"Wang says both Hong Kong's and the mainland's organ donation rates still lag far behind those of developed economies. "They have reached a plateau and have made relatively adequate utilization of organ donations from the deceased. We have much room to develop in this regard."

"He says that while officials explore innovative approaches concerning living-organ donations, the priority should still focus on how to boost people's willingness to register as organ donors and better utilize the organs. "These are the so-called 'low hanging fruit'. It would be wise to concentrate our limited resources on the most rewarded option."


Wednesday, June 28, 2023

Freezing, thawing and transplanting a rat kidney: a first step towards organ banking

 A kidney has been frozen, thawed, and successfully transplanted, into a rat.  Maybe we'll live to see organ banking...

Vitrification and nanowarming enable long-term organ cryopreservation and life-sustaining kidney transplantation in a rat model   by Zonghu Han, Joseph Sushil Rao, Lakshya Gangwar, Bat-Erdene Namsrai, Jacqueline L. Pasek-Allen, Michael L. Etheridge, Susan M. Wolf, Timothy L. Pruett, John C. Bischof & Erik B. Finger, Nature Communications volume 14, Article number: 3407 (2023) 

Abstract: Banking cryopreserved organs could transform transplantation into a planned procedure that more equitably reaches patients regardless of geographical and time constraints. Previous organ cryopreservation attempts have failed primarily due to ice formation, but a promising alternative is vitrification, or the rapid cooling of organs to a stable, ice-free, glass-like state. However, rewarming of vitrified organs can similarly fail due to ice crystallization if rewarming is too slow or cracking from thermal stress if rewarming is not uniform. Here we use “nanowarming,” which employs alternating magnetic fields to heat nanoparticles within the organ vasculature, to achieve both rapid and uniform warming, after which the nanoparticles are removed by perfusion. We show that vitrified kidneys can be cryogenically stored (up to 100 days) and successfully recovered by nanowarming to allow transplantation and restore life-sustaining full renal function in nephrectomized recipients in a male rat model. Scaling this technology may one day enable organ banking for improved transplantation.



Monday, June 12, 2017

Organ preservation could bring big changes to transplantation

Transplantation would be a lot less hectic if organs could be preserved. Here's a 42-author paper (the biggest coauthorship I've been involved in) that discusses some of the possibilities.

The promise of organ and tissue preservation to transform medicine 
 Sebastian Giwa, Jedediah K Lewis, Luis Alvarez, Robert Langer, Alvin E Roth, George M Church, James F Markmann, David H Sachs, Anil Chandraker, Jason A Wertheim, Martine Rothblatt, Edward S Boyden, Elling Eidbo, W P Andrew Lee, Bohdan Pomahac, Gerald Brandacher, David M Weinstock, Gloria Elliott, David Nelson, Jason P Acker, Korkut Uygun, Boris Schmalz, Brad P Weegman, Alessandro Tocchio, Greg M Fahy, Kenneth B Storey, Boris Rubinsky, John Bischof, Janet A W Elliott, Teresa K Woodruff, G John Morris, Utkan Demirci, Kelvin G M Brockbank, Erik J Woods, Robert N Ben, John G Baust, Dayong Gao, Barry Fuller, Yoed Rabin, David C Kravitz, Michael J Taylor & Mehmet Toner

Tuesday, June 27, 2023

The Ethics of Organ Markets | Glenn Loury & Sally Satel | The Glenn Show

Genn Loury interviews Sally Satel, starting with a discussion of political correctness in medicine, and moving on to include (just before minute 13)  kidney disease and carefully regulated compensation for kidney donors as a way to address the perennial shortage of kidney transplants.

"Satel: kidney transplantation is "the only arena in healthcare that's a really direct way. ... "There's a lifeboat-ethics dimension to it."

Monday, June 26, 2023

Harry Markowitz (1927-2023)

 Harry Markowitz, who invented modern portfolio theory, and did much beside, has died.

Here's his NYT obituary, which was apparently prepared long in advance.

Harry Markowitz, Nobel-Winning Pioneer of Modern Portfolio Theory, Dies at 95. He overturned the traditional approach to buying stocks by examining the relationship between risk and reward. By Robert D. Hershey Jr.

I’m not a one-shot Nobel laureate — only doing one thing,” Dr. Markowitz said in an interview for this obituary in 2014. Although he was 87 at the time, he was embarked on a monumental analysis of securities risk and return."


PORTFOLIO SELECTION, by Harry Markowitz, The Journal of Finance Volume 7, Issue 1 p. 77-91 First published: March 1952


Here's the beginning of the 1990 Nobel Prize press release:

16 October 1990


The Royal Swedish Academy of Sciences has decided to award the 1990 Alfred Nobel Memorial Prize in Economic Sciences with one third each, to

Professor Harry Markowitz, City University of New York, USA,
Professor Merton Miller, University of Chicago, USA,
Professor William Sharpe, Stanford University, USA,

for their pioneering work in the theory of financial economics.

Harry Markowitz is awarded the Prize for having developed the theory of portfolio choice;
William Sharpe, for his contributions to the theory of price formation for financial assets, the so-called, Capital Asset Pricing Model (CAPM); and
Merton Miller, for his fundamental contributions to the theory of corporate finance.


Here's the citation for the 1989 von Neumann theory prize in operations research:

"1989 John von Neumann Theory Prize:  

"Harry M. Markowitz received the 1989 John von Neumann Theory Prize. Dr. Markowitz, presenter Ellis Johnson noted, contributed ground-breaking work in three areas: portfolio selection, mathematical programming, and simulation.

"Harry Markowitz is the Marvin Speiser Distinguished Professor of Finance and Economics at Baruch College, NYC. He developed the portfolio selection model in his Ph.D. thesis at the University of Chicago. First published in 1952, today his model is one of the most widely used quantitative tools for investment analysis.

"During the late 50s Markowitz worked on mathematical programming at the RAND Corp. and also did his ground-breaking work on factoring bases and maintaining sparsity in the course of solving linear programs, in effect introducing the triangularization or LU factorization in place of inversion of the basis. His selection criterion for reducing fill-in when forming basis factors is the well-known Markowitz criterion and is still used in state-of-the-art codes for both LU and Cholesky factorizations. Markowitz's third main area of activity involved codifying the underlying notions of simulation by defining a world view composed of entities having attributes and belonging to sets that have defined relationships with each other. The state of the world changes through events, which are triggered by time. Based on this, in the 60s he developed a high-level simulation language, SIMSCRIPT, and in the 80s has collaborated with IBM researchers to develop EAS-E, an integrated data base, modeling and applications development language.

Dr. Markowitz told OR/MS Today that the award was a great honor and a reflection of the influence of von Neumann on portfolio theory."

Sunday, June 25, 2023

Saturday, June 24, 2023

Challenge trial for Covid in England reveals airborne superspreaders

 Nature has a news story about a Lancet Microbe paper reporting the challenge trial. See links to and excerpts from both below.

Here's the Nature story:

What makes a COVID superspreader? Scientists learn more after deliberately infecting volunteers. A rigorous study identifies ‘supershedders’ who spew huge amounts of virus into the air — despite having only mild symptoms. by Saima Sidik

"A study of people who were intentionally infected with SARS-CoV-2 has provided a wealth of insights into viral transmission — showing, for example, that a select group of people are ‘supershedders’ who spew vastly more virus into the air than do others1.

"The publication describes data from a controversial ‘challenge study’, in which scientists deliberately infected volunteers with the virus that causes COVID-192. Although the approach drew opposition, the work has now yielded data on questions central to public health, such as whether the severity of symptoms correlates with how contagious people are and whether home COVID-19 tests can play a part in reducing viral spread.


"Challenge studies are “very bold”, says Gandhi. Some people argue that it’s unethical to give people an infection that can cause severe illness, but the research design comes with benefits. Challenge studies can substantially speed up vaccine testing, and they’re the only way to understand certain aspects of COVID-19, such as the stage before people test positive or develop symptoms.

"Researchers inoculated 34 healthy young participants by squirting a known quantity of viral particles up their noses. Eighteen developed infections and spent at least 14 days confined to hospital rooms. Each day, researchers measured viral levels in the participants’ noses and throats, in the air, and on the participants’ hands and various surfaces in the rooms.


"Of the 18 participants who developed infections, 2 shed 86% of the airborne virus detected over the course of the entire study — even though both had only mild symptoms. Previous research3 has provided evidence for the existence of superspreaders who infect large numbers of people. But whether such people are also ‘supershedders’ who emit copious amounts of virus, or simply have many social contacts, was up for debate


"None of the participants emitted a detectable level of virus into the air before testing positive, and only a small proportion of them left detectable virus on their hands, on surfaces or on masks that they donned temporarily.

"By the time they tested positive, most participants had already experienced mild symptoms, such as tiredness or muscle aches. That means that if people test as soon as they detect symptoms, rapid tests “can be a powerful tool” for controlling viral spread, says infectious-disease researcher Christopher Brooke at the University of Illinois at Urbana-Champaign.


And here's the original paper:

Jie Zhou, Anika Singanayagam, Niluka Goonawardane, Maya Moshe, Fiachra P Sweeney, Ksenia Sukhova, Ben Killingley, Mariya Kalinova, Alex J Mann, Andrew P Catchpole, Michael R Barer, Neil M Ferguson, Christopher Chiu, Wendy S Barclay, Viral emissions into the air and environment after SARS-CoV-2 human challenge: a phase 1, open label, first-in-human study, The Lancet Microbe, 2023, ISSN 2666-5247, (

"After controlled experimental inoculation, the timing, extent, and routes of viral emissions was heterogeneous. We observed that a minority of participants were high airborne virus emitters, giving support to the notion of superspreading individuals or events. Our data implicates the nose as the most important source of emissions. Frequent self-testing coupled with isolation upon awareness of first symptoms could reduce onward transmissions."

Friday, June 23, 2023

2023 Chinese Economists Society Annual Conference, June 24-25, 2023

I'll be speaking via zoom at 6:40pm this evening in California/tomorrow morning in China, June 24, 9:40-10:40am ) at the 

2023 Chinese Economists Society Annual Conference,  June 24-25, 2023 at Zhongnan University of Economics and Law, Wuhan.

"The conference includes invited keynote speeches, invited speakers sessions and panels, and parallel sessions. We are also planning for Pre-Conference events which will be conducted in Chinese and are more geared toward policy.

Confirmed keynote speakers include:

Joshua Angrist, 2021 Nobel Memorial Prize Winner in Economic Sciences. Ford Professor of Economics at MIT.

Justin Yifu Lin, Dean of Institute of New Structural Economics, Dean of Institute of South-South Cooperation and Development and Professor and Honorary Dean of National School of Development at Peking University.

Eric Maskin, 2007 Nobel Memorial Prize Winner in Economic Sciences. Professor at Harvard University of Economics and Mathematics. Albert O. Hirschman Professor of Social Science at the Institute for Advanced Study.

Al Roth, 2012 Nobel Memorial Prize Winner in Economic Sciences. Craig and Susan McCaw Professor of Economics at Stanford University, and the Gund Professor of Economics and Business Administration Emeritus at Harvard University.

 Update:  My talk title is "Economists as Engineers: How game theory led to practical market design."

Here's a sharable zoom link: .

    Passcode: 029136