School choice and related matching algorithms in France, by Vincent Iehlé and Julien Jacqmin

Here's a recent paper that looks at the assignment of students to some of France's Grandes Ecoles, and draws some conclusions about the preferences for those schools.

SIGEM : analyse de la procédure d’affectation dans les grandes écoles de management,, Vincent Iehlé, Julien Jacqmin, Dans Revue économique 2023/2 (Vol. 74), pages 139 à 168 (SIGEM: analysis of the assignment procedure in major management schools)

"First, we list the expected properties of the assignments produced by the SIGEM. To do this we identify the SIGEM algorithm. It is quite standard in this type of environment since it is the “schools” version of the algorithm of Gale and Shapley [1962]. Based on this information, we show that assignments satisfy a stability property that is crucial in educational systems since it guarantees fair treatment of declared wishes and rankings. On the other hand, the use of this version of the algorithm of Gale and Shapley [1962], in opposition to the "candidate" version, raises two reservations concerning, on the one hand, the sub-optimality of the assignments from the point of view candidates and, on the other, the theoretical absence of simple strategies for candidates to play when submitting their wishes. This theoretical analysis of the algorithm is completed by a discussion on the specificities of the SIGEM procedure which can explain the formation of strategic behaviors. The second contribution concerns the use made of the results of this procedure in the case of SIGEM. We show how post-assignment data is used to determine the influential ranking of SIGEM from the so-called cross-dismissal matrix, itself based on the candidates' revealed preferences and their final assignments. The last contribution concerns the exploitation of a stylized fact which justifies the joint analysis of the algorithm and the SIGEM classification. The post-assignment data indeed reveal the existence of a hierarchy of schools that is very rigid and that achieves a consensus among students. This point is particularly interesting because it finally allows to have a finer look at the theoretical properties of the algorithm, the alignment of the preferences of the candidates tending to limit the impact of the negative effects associated with the use of the version "schools" of the algorithm of Gale and Shapley [1962]."

...

"Figure 2 presents for each school the number of ranked candidates and the number of wishes expressed for the school among these ranked. It seems to confirm the existence of these voluntary self-censorship strategies. In particular, we observe a significant loss for schools of average attractiveness (for example, AUDENCIA, NEOMA, SKEMA) which are more likely to be subject to both downward and upward truncation on the part of candidates ."

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Recall also, 

Strategic Issues in the French Academic Job Market, by Guillaume Haeringer, Vincent Iehlé In Revue économique Volume 61, Issue 4, 2010, pages 697 to 721

Conference on Economic Design, University of Girona, June 15th-17th, 2023

 Conference on Economic Design, University of Girona,  June 15th-17th,  2023

Here is the program.

Plenary Sessions

June 15th, 19:00 Murat Sertel Lecture

Jordi Massó: On Strategy-proofness and the Salience of Single-peakedness in a Private Goods Allotment Problem

Chair: Salvador Barberà

June 16th, 17:00 Paul Kleindorfer Lecture

Alex Teytelboym: Duality in Market Design

Chair: Tommy Andersson

June 17th, 12:15 Leonid Hurwicz Lecture

Gabrielle Demange: Dual activities in a social network

Chair: Szilvia Pápai

June 15th, 16:00 Nedim Okan Young Scholar Prize

Zhuoqiong Chen: All-pay auctions with private signals about opponents’ values

Chair: Remzi Sanver

Introduction: Ayça Ebru Giritligil

Market design in major league baseball

 The rules of professional Major League Baseball are changing in an effort to make attending the games more popular.  Among the rule changes are rules requiring pitchers to pitch more quickly, including rules that prevent them from too often taking time to defend against base stealing.  It's a good example of a game within a game: the players have, over time, adjusted their behavior to win games under the existing rules. These behaviors, collectively, have caused games to slow down, take more time, and be less easily appreciated as exciting.  That in turn makes it hard for baseball to fill stadium seats.

The NY Times has the story: 

How New Rules Turned Back the Clock on Baseball, By Ben Blatt and Francesca ParisMay 24, 2023

"Baseball’s future may look a lot like its past.

"Nearly two months into the season, a series of rule changes — including the new pitch clock, enlarged bases and a ban on the infield shift — has translated into a game that evokes the 1980s more than the 2020s."

Data privacy concerns in the U.S. and Europe

A selection from many news stories that touch on data privacy concerns (in the U.S. about Tiktok, in Europe about Facebook...and about DNA):

From the NYT:

Driver’s Licenses, Addresses, Photos: Inside How TikTok Shares User Data. Employees of the Chinese-owned video app have regularly posted user information on a messaging and collaboration tool called Lark, according to internal documents.  By Sapna Maheshwari and Ryan Mac

"Alex Stamos, the director of Stanford University’s Internet Observatory and Facebook’s former chief information security officer, said securing user data across an organization was “the hardest technical project” for a social media company’s security team. TikTok’s problems, he added, are compounded by ByteDance’s ownership.

“Lark shows you that all the back-end processes are overseen by ByteDance,” he said. “TikTok is a thin veneer on ByteDance.”

********

********

From the WSJ:

Former ByteDance Executive Claims Chinese Communist Party Accessed TikTok’s Hong Kong User Data. Allegation is made in suit against TikTok parent company; ByteDance says it vigorously opposes the claim. By Georgia Wells

"A former executive at ByteDance, the parent company of the hit video-sharing app TikTok, alleges in a legal filing that a committee of China’s Communist Party members accessed the data of TikTok users in Hong Kong in 2018—a contention the company denies. 

"The former executive claims the committee members focused on civil rights activists and protesters in Hong Kong during that time and accessed TikTok data that included their network information, SIM card identifications and IP addresses, in an effort to identify and locate the users. The former executive of the Beijing-based company said the data also included the users’ communications on TikTok.

From the Guardian:

Revealed: the contentious tool US immigration uses to get your data from tech firms. Documents show Ice has sent Google, Meta and Twitter at least 500 administrative subpoenas for information on their users.  by Johana Bhuiyan

"The US Immigration and Customs Enforcement Agency (Ice) sent tech giants including Google, Twitter and Meta at least 500 administrative subpoenas demanding sensitive personal information of users, documents reviewed by the Guardian show.

"The practice highlights the vast amount of information Ice is trying to obtain without first showing probable cause. Administrative subpoenas are typically not court-certified, which means companies are not legally required to comply or respond until and unless a judge compels them to. The documents showed the firms handing over user information in some cases, although the full extent to which the companies complied is unclear."

**********

From the WSJ:

Meta Fined $1.3 Billion Over Data Transfers to U.S.  Decision places pressure on Washington to implement surveillance changes for Europe to allow Meta to keep the data spigot open.  By Sam Schechner

"Meta’s top privacy regulator in the EU said in its decision Monday that Facebook has for years illegally stored data about European users on its servers in the U.S., where it contends the information could be accessed by American spy agencies without sufficient means for users to appeal."

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From the Guardian:

NHS data breach: trusts shared patient details with Facebook without consent. Observer investigation reveals Meta Pixel tool passed on private details of web browsing on medical sites."by Shanti Das

"Records of information sent to the firm by NHS websites reveal it includes data which – when linked to an individual – could reveal personal medical details.

"It was collected from patients who visited hundreds of NHS webpages about HIV, self-harm, gender identity services, sexual health, cancer, children’s treatment and more.

...

"In one case, Buckinghamshire Healthcare NHS trust shared when a user viewed a patient handbook for HIV medication. The name of the drug and the NHS trust were sent to the company along with the user’s IP address and details of their Facebook user ID."

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From the NYT:

Your DNA Can Now Be Pulled From Thin Air. Privacy Experts Are Worried. Environmental DNA research has aided conservation, but scientists say its ability to glean information about human populations and individuals poses dangers.  By Elizabeth Anne Brown

"Forensic ethicists and legal scholars say the Florida team’s findings increase the urgency for comprehensive genetic privacy regulations. For researchers, it also highlights an imbalance in rules around such techniques in the United States — that it’s easier for law enforcement officials to deploy a half-baked new technology than it is for scientific researchers to get approval for studies to confirm that the system even works."

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From the LA Times:

Microsoft will pay $20 million to settle U.S. charges of illegally collecting children’s data

"Microsoft will pay a fine of $20 million to settle Federal Trade Commission charges that it illegally collected and retained the data of children who signed up to use its Xbox video game console.

"The agency charged that Microsoft gathered the data without notifying parents or obtaining their consent, and that it also illegally held on to the data. Those actions violated the Children’s Online Privacy Protection Act, the FTC stated."

Digital data yields suspect in Idaho murders (NYT)

 The NYT has the story of how a wide ranging search of a large variety of digital data  led to an arrest of a suspect (whose trial hasn't yet begun):

“Inside the Hunt for the Idaho Killer,” by Mike Baker, New York Times, June 10, 2023

"“Online shopping, car sales, carrying a cellphone, drives along city streets and amateur genealogy all played roles in an investigation that was solved, in the end, as much through technology as traditional sleuthing.

...

"A week after the killings, records show, investigators were on the lookout for a certain type of vehicle: Nissan Sentras from the model years 2019 to 2023. Quietly, they ran down details on thousands of such vehicles, including the owners’ addresses, license plate numbers and the color of each sedan.

"But further scrutiny of the video footage produced more clarity, and on Nov. 25 the police in Moscow asked law enforcement agencies to look for a different type of car with a similar shape: white Hyundai Elantras from the model years 2011 to 2013.

"Just across the state border, at Washington State University, campus police officers began looking through their records for Elantras registered there. 

...

"The hunt broadened as investigators vacuumed up more records and data. They had already sought cellphone data for all phones that pinged cell towers within a half-mile of the victims’ house from 3 a.m. to 5 a.m., according to search warrant filings. 

...

"after getting back data on [one of the victim]’s account on the Tinder dating app, detectives asked for details on 19 specific account-holders, including their locations, credit card information and any “private images, pictures or videos” associated with the accounts.

...

"Investigators were also working with a key piece of evidence: a Ka-Bar knife sheath, branded with a U.S. Marine Corps logo, that had been found next to two of the victims. They initially began looking for local stores that may have sold the weapon, and then fanned out.

"A request to Amazon sought the order histories of account holders who had purchased such knives. A follow-up request to eBay focused on a series of specific users, seeking their purchase histories. Some had connections to the area — including one in Idaho and two in Washington State...

...

"Forensic teams had examined the knife sheath and found DNA that did not belong to any of the inhabitants of the house. They ran the sample through the F.B.I.’s database, which contains millions of DNA profiles of past criminal offenders, but according to three people briefed on the case, they did not get a match.

"At that point, investigators decided to try genetic genealogy, a method that until now has been used primarily to solve cold cases, not active murder investigations.

...

"F.B.I. personnel ...{spent] days building out a family tree that began with a distant relative.

"By the morning of Dec. 19, records show, investigators had a name: Bryan Kohberger. He had a white Elantra. He was a student at a university eight miles from the murder scene.

...

"On Dec. 23, investigators sought and received Mr. Kohberger’s cellphone records. The results added more to their suspicions: His phone was moving around in the early morning hours of Nov. 13, but was disconnected from cell networks — perhaps turned off — in the two hours around when the killings occurred.

"Four days later, agents in Pennsylvania managed to retrieve some trash from Mr. Kohberger’s family residence, sending the material to the Idaho State Police forensic lab. Checking it against their original DNA profile, the lab was able to reach a game-changing conclusion: The DNA in the trash belonged to a close relative of whoever had left DNA on the knife sheath.

"Mr. Kohberger was arrested on Dec. 30."

Canada to require health warnings on individual cigarettes

 The Washington Post has the story:

Canada to require health warnings on individual cigarettes  By Sarah Dadouch

"Beginning next year, cigarettes sold in Canada will bear one of six messages in English and French. They include “TOBACCO HARMS CHILDREN,” “POISON IN EVERY PUFF” and “SMOKING CAUSES IMPOTENCE.” Health Canada announced the regulation Wednesday for World No Tobacco Day.

“This bold step will make health warning messages virtually unavoidable,” mental health and addictions minister Carolyn Bennett said. With updated graphic images on cigarette packages, she said in a statement, the labels “will provide a real and startling reminder of the health consequences of smoking.”

...

"Around 48,000 people in Canada die as a result of tobacco use each year, according to Health Canada. That’s more than those who die as a result of alcohol, opioids, suicides, murders and traffic collisions combined."

Decreasing kidney discards--review, and a call for clinical trials

 A review of discarded kidneys from a large OPO revealed only modest margins for improved utilization.

Bunnapradist, Suphamai MD1; Rosenthal, J. Thomas MD1; Huang, Edmund MD2; Dafoe, Donald MD3; Seto, Tom PharmD4; Cohen, Aaron BS4; Danovitch, Gabriel MD1. Deceased Donor Kidney Nonuse: A Systematic Approach to Improvement. Transplantation Direct 9(6):p e1491, June 2023. | DOI: 10.1097/TXD.0000000000001491

"Background. A large number of procured kidneys continue not to be transplanted, while the waiting list remains high.

"Methods. We analyzed donor characteristics for unutilized kidneys in our large organ procurement organization (OPO) service area in a single year to determine the reasonableness of their nonuse and to identify how we might increase the transplant rate of these kidneys. Five experienced local transplant physicians independently reviewed unutilized kidneys to identify which kidneys they would consider transplanting in the future. Biopsy results, donor age, kidney donor profile index, positive serologies, diabetes, and hypertension were risk factors for nonuse.

"Results.  Two-thirds of nonused kidneys had biopsies with high degree of glomerulosclerosis and interstitial fibrosis. Reviewers identified 33 kidneys as potentially transplantable (12%).

"Conclusions. Reducing the rate of unutilized kidneys in this OPO service area will be achieved by setting acceptable expanded donor characteristics, identifying suitable well-informed recipients, defining acceptable outcomes, and systematically evaluating the results of these transplants. Because the improvement opportunity will vary by region, to achieve a significant impact on improving the national nonuse rate, it would be useful for all OPOs, in collaboration with their transplant centers, to conduct a similar analysis."

...

"One posited cause for continued high nonuse rates is that transplant physicians are overly conservative, content with doing a small number of cases relative to the need. Both the existence of a “weekend effect”8 and a paper by French investigators stating 62% of kidneys not transplanted in the United States would be transplanted in France9 are used in support of this contention. Mistaken reliance on kidney biopsies is an additional factor implicated in inappropriate kidney nonuse.10 An alternative explanation is that transplant physicians and surgeons have not been persuaded that it is safe to transplant high-risk kidneys into older recipients based on retrospective registry studies.

"With this background in mind, and with a strong desire to respond to the imperative of increasing the use of heretofore nontransplanted kidneys, we undertook an analysis of unused kidneys in our OPO service area. Goal one was to understand the interplay of factors causing nonuse including donor demographics and biopsies. Goal two was to use the information from goal one to devise a plan to increase the kidney utilization rate in our service area.

"OneLegacy is the federally designated OPO for 7 counties in Southern California with a population of approximately 20 million. In 2019, which was chosen as the year of study because it was the last full year before the COVID-19 pandemic, OneLegacy served 10 centers with kidney transplant programs.11

"There were 1064 kidneys procured from 552 donors; 740 were transplanted and 324 were not transplanted. Forty-seven of the 324 (14.5%) were not offered for transplant because of absolute contraindications including cancers in the kidney, infections discovered during procurement, and abnormalities such as multicystic dysplastic kidneys. There were 5 surgical injuries (0.47%)—1 stripped ureter and 4 vascular injuries—all of which were determined to be nonrepairable by a transplant surgeon highly experienced with repair techniques. These kidneys were excluded from the study. The remaining 272 kidneys were offered for transplant and turned down by all local centers and, in turn, by all regional and national centers. Fourteen kidneys were provisionally accepted by and transported to nonlocal centers but, ultimately, not utilized due to prolonged cold ischemic times or findings on biopsies performed at the export center.

...

"One reason that the nonuse problem has proven intractable is that, even though it has been asserted that most nonused kidneys in the United States are safe to transplant, clinicians making the decisions in real time seem not to agree. Nor is there widespread enthusiasm for transplanting suboptimum kidneys into elderly recipients, despite papers promoting it,15 possibly because it is not entirely clear which older dialysis patients really benefit from transplantation.16

"The thought experiment of experienced local physicians reviewing procured but not transplanted kidneys appears to confirm this hypothesis. Despite French studies suggesting that 62% of kidneys not utilized in the United States would be transplanted in France, only 12% of kidneys were thus identified by our team of physicians, each of whom were highly motivated to reduce nonuse kidneys and highly knowledgeable about registry studies claiming safety of expanded donor criteria.10 If highly knowledgeable and experienced transplant physicians and surgeons—highly motivated to decrease nonuse—have not significantly changed kidney acceptance criteria, they are unlikely to be persuaded or respond to regulatory pressure to cause them to perform transplants that they feel would violate their responsibility to patients. Reducing the nonuse rate to ≤5% is unlikely under these conditions. Nonetheless, this experience does inform how improvement can occur.

"The alternative pathway to improvement in our service area is a more systematic prospective approach, in other words, an authentic clinical trial. The elements of such a trial would include codifying as precisely as possible the inclusion criteria for transplantable “suboptimal” donors, determining recipient criteria, extensive informed consent conversations, optimization of the organ offer process to minimize cold ischemia times, and outcomes tracking including quality of life and cognitive assessment. It should be decided in advance what will constitute an acceptable outcome for primary nonfunction and 1-y graft and patient survival."

More kidney exchange in the UAE--

 Kidney exchange in the UAE, with the assistance of the Alliance for Paired Kidney Donation (AKPD), took another step forward, with a three way exchange.

Here is the press release fron the Cleveland Clinic Abu Dhabi:

Cleveland Clinic Abu Dhabi supports Abu Dhabi’s Paired Kidney Donation Program by successfully completing a triple swap kidney transplant 

"Cleveland Clinic Abu Dhabi, a Mubadala Health partner, played a major role in a groundbreaking triple ‘kidney swap’ transplant case in the UAE where three patients received life-saving organs under Abu Dhabi’s Paired Kidney Donation Program."

Snowden and state surveillance: the view from The Guardian, ten years later

 Here's a look back at the Snowden affair (publication of documents about government surveillance) by the then editor in chief of the Guardian, one of the newspapers that took the lead.

Ten years ago, Edward Snowden warned us about state spying. Spare a thought for him, and worry about the future by Alan Rusbridger

"one story the Guardian published 10 years ago today exploded with the force of an earthquake.

"The article revealed that the US National Security Agency (NSA) was collecting the phone records of millions of Verizon customers. In case anyone doubted the veracity of the claims, we were able to publish the top secret court order handed down by the foreign intelligence surveillance court (Fisa), which granted the US government the right to hold and scrutinise the metadata of millions of phone calls by American citizens.

...this was but the tip of a very large and ominous iceberg.

...

"the Guardian (joined by the Washington Post, New York Times and ProPublica) led the way in publishing dozens more documents disclosing the extent to which US, UK, Australian and other allied governments were building the apparatus for a system of mass surveillance

...

"It led to multiple court actions in which governments were found to have been in breach of their constitutional and/or legal obligations. It led to a scramble by governments to retrospectively pass legislation sanctioning the activities they had been covertly undertaking. And it has led to a number of stable-door attempts to make sure journalists could never again do what the Guardian and others did 10 years ago.

"Even now the British government, in hastily revising the laws around official secrecy, is trying to ensure that any editor who behaved as I did 10 years ago would face up to 14 years in prison.

...

"The British government believed that, by ordering the destruction of the Guardian computers, they would effectively silence us. In fact, we simply transferred the centre of publications to New York, under ​the paper’s then US editor, Janine Gibson.

...

"The notion that the state has no right to enter a home and seize papers was established in English law in the famous case of Entick v Carrington (1765), which later became the basis for the US fourth amendment. In a famous passage, Lord Camden declared: “By the laws of England, every invasion of private property, be it ever so minute, is a trespass.”

"When I went out to talk about the Snowden case to assorted audiences (including, after a suitable gap, at MI5 itself), I would begin by asking who in the audience would be happy to hand over all their papers to a police officer knocking on their front door, even if they assured them they would only examine them if there was sufficient cause.

"Never, in any of these talks, did a single member of any audience raise a hand. Yes, people valued their security and were open to persuasion that, with due process and proper oversight, there would be occasions when the state and its agencies should be granted intrusive powers​ in specific circumstances​. But the idea of blanket, suspicionless surveillance – give us the entire haystack and we’ll search for the needle if and when it suits us – was repellent to most people."

Interview in the Brazil Journal

 I was interviewed for the Brazil Journal by Giuliano Guandalini. The interview was conducted in English, but appears in Portuguese. We discussed controversial markets generally, including kidney exchange, which is not legal yet in Brazil.

Troca de rins. Drogas. Barriga de aluguel. Este Nobel sugere liberar tudo  (Kidney exchange. Drugs. Surrogacy...)

 Here's a snippet that comes through pretty clearly in retranslation back into English by Google Translate:

"In the US and many other countries, his work and that of other researchers has contributed to improving the waiting list for kidney transplants. In Brazil, we continue with the traditional system, with a long wait for donors. Why is it so difficult to make reforms of this kind in public services based on the teachings of modern economics?  

"A transplant always depends on an organ donation, whether from a dead person or a living individual. It is natural that family members and society in general are concerned about how this will be done in an ethical and careful manner. 

"Brazil does a lot of transplants. So there is no restriction on the medical capacity side so that more transplants can be done. But when we look at total kidney transplants in relation to population size, the number is not that big. 

"Meanwhile, there are thousands of people on dialysis because transplants have not been enough. The issue, therefore, is to allow more donations to occur in life, and changing kidneys is a way for people to help save someone they love. 

"Brazil may be one of the next countries to carry out the exchange of kidneys. Some experimental surgeries have already been performed, with legal authorization. Researchers will be able to gain support to perform more operations of this type and then, perhaps, society will be able to convince itself of the importance of changing kidneys. 

"What are the obstacles that prevent the adoption of organ exchange? Are they ethical, moral, religious issues? 

"A little bit of all those things. There are those concerned that poor and vulnerable people may have their organs stolen. Evidently, there must be complete assurance that this will not happen. But of course the poor would also like to save the lives of loved ones by giving them a kidney. "

Alex Chan makes his 'final presentation' at Stanford.

 

Note Alex's shoes

Organ donation day in Germany

 Yesterday was organ donation day in Germany. Here's a post from the German Health Economics Association (DGGÖ): Day of Organ Donation on June 3, 2023

"In Germany, there are about 8,500 people waiting for an organ donation (www.Bundesärztekammer.de). On the Day of Organ Donation, the German Society for Health Economics (dggö) wants to emphasize the urgency of increasing organ donation rates to improve the lives of these individuals. This applies equally to deceased organ donation and living donation. An international comparison also shows that there is room for improvement in Germany: Both in terms of living and deceased donations per million population, Germany lags behind in the EU (see Figure 1).

...

"On Wednesday, May 31, 2023, Nobel laureate in economics and professor at Stanford University, Alvin Roth, spoke to a broad audience in the 6th virtual dggö Talk (see https://www.dggoe.de/aktuelles for details) about the possibilities of kidney exchange between compatible but previously unknown pairs and the implementation of cross-over donations and exchange chains in the US.

"Unlike in the US, in Germany, living donation outside of close family is only possible if a close relationship between the donor and recipient has been officially confirmed. Alvin Roth noted in the case of cross-over kidney donations, that it was very complicated for German hospitals to build up and prove a close relationship between two pairs of donors in front of a commission. This should be simplified, especially considering the overall strong support for kidney exchange among the German population. As Figure 2 from a survey conducted by Roth and Wang (2020) illustrates, 79% even agree to kidney exchange across borders and outside of family and friends, although such an exchange is currently not legally possible in Germany.

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Earlier: 

Tuesday, May 30, 2023

Kidney exchange, around the world and in Germany? German Health Economics Association (DGGÖ) webinar 

The critical role of Kelso & Crawford in the development of the stable matching literature

 In the physics literature there has long been an interest in economics (econophysics) that takes many forms. Here's a review of stable matching, which identifies Kelso and Crawford as a critical step in the evolution of the matching literature following Gale and Shapley.

Danilov, V.I. Review of the Theory of Stable Matchings and Contract Systems. Computational Mathematics and Mathematical Physics. 63, 466–490 (2023). https://doi.org/10.1134/S0965542523030065

"The real development was started by the work of Kelso and Crawford [123], who considered the more general problem of hiring workers (many-to-one). Their problem statement differed from the college admission problem in that the behavior of firms was more flexible than simply setting a quota in [81]. When hiring workers, the firm dealt with a “crowd” of candidates and chose the group of workers it needed from among this crowd. The description of the behavior of such a firm was no longer given by a simple ranking of candidates, but by a choice function. Below, we consider such functions in more detail. An important merit of Kelso and Crawford was that they found the “correct” condition on the choice function, which generalized the Gale–Shapley “linear” choice and which had previously appeared in economics as a substitutability condition. (Later it turned out that such a condition had already been introduced in the choice theory [152] under the name path independence.) Using this condition, Kelso and Crawford [123] showed that the Gale–Shapley algorithm works and gives a stable distribution of workers among firms. In [88], the notion of substitutability was used in the case of indivisible goods and led to a series of papers on this topic (see [79, 51, 65, 103]). Two years later, Roth [158] showed that the same substitutability condition also works well in a many-to-many situation, when firms could hire many workers and workers could work in several firms, see [62]. The results of this direction were summed up in the monograph [160]."

Dissertation advisors and job market outcomes by Rose and Shekhar

 Here's a paper on the economics job market, and the influence of dissertation advisers.

Adviser Connectedness and Placement Outcomes in the Economics Job Market, by Michael E. Rose and Suraj Shekhar, forthcoming in Labour Economics

Abstract: We study the role of social networks in the academic job market for graduate students of Economics. We find that the connectedness of a student’s advisor in the coauthor network significantly improves her job market outcome. We use two identification strategies and find that a) higher Eigenvector centrality of an adviser leads to her student getting placed at a better ranked institution, and b) larger distance between an adviser and an institution decreases the probability that her students are placed there. Our study sheds light on the importance of social connections in a labour market where information frictions regarding job openings are virtually absent.

...

"Our setting, the academic job market for Economists, is special in that information frictions regarding job openings are (almost) absent due to Job Openings for Economists. Thus, our finding that social networks play a role in this market is likely because they help decrease the uncertainty about an applicant’s quality."

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I'm reminded of the timeless joke about how rabbits eat wolves: if you don't know it, there are many versions on the internet, here  (and this one comes with a bonus joke: Rabbit's Ph.D. Thesis and Lion's Watch Repair Business).

Canadian kidney exchange reaches 1000 transplants

 The May 2023 update from Canadian Blood Services shows that Canada's kidney paired donation program recently performed its 1,000th transplant.

Earlier:

Wednesday, December 8, 2010

National kidney exchange in Canada

Here's a recent announcement from Canadian Blood Services: Kidney Exchange Registry Goes National, Living Donor Paired Exchange becomes first Canada-wide organ donation registry

Kidney exchange progress in Europe

 The program on European Cooperation in Science and Technology  (COST) has just published an update on steps being taken to advance kidney exchange in Europe, including the goal of more cross-border exchange.

The crucial role of Kidney Exchange Programmes and the ENCKEP and KEP-SOFT innovations making it possible

"Setting up KEPs is difficult due to the ethical, legal, practical, and logistical considerations that must be faced. These include ratifying policy decisions, establishing a software infrastructure, and satisfying clinical requirements. Additionally, KEPs vary across European countries in terms of policy, clinical practice, and optimisation methods. For instance, the maximum number of recipients allowed to exchange donors in a single “cycle” differs between the Netherlands and the UK. Furthermore, some countries allow non-directed donation while others prohibit it. Crossmatching** processes also vary. The ENCKEP and KEP-SOFT network has proved instrumental in meeting many of these challenges. And its associated software addresses many of these variations.

...

"On 15 June 2023, EU4Health will publish a call for proposals to implement an EU-wide KEP. On page 65, the announcement makes specific reference to the KEP-SOFT software. This presents an exciting potential future opportunity to influence further developments in KEPs in the European context and to widen the user-base of the KEP-SOFT software"

HT: David Manlove

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When I first read the last paragraph above I thought that "KEP"  probably stood for "Kidney Exchange Program," and that the proposal was to make that EU-wide rather than country by country. But it turns out that "KEP" stands for Knowledge Exchange Platform (KEP), so the progress is a bit less specific than I had hoped. But on page 65 it does include a "Call for proposals: action grants on facilitating organ paired exchange." It states that "In view of the scarcity of organs available for transplantation, there is a need to strengthen the exchange schemes among Member States, with a clear added value for European patients, as such exchange schemes can save the life of patients."

Kidney exchange, around the world and in Germany? German Health Economics Association (DGGÖ) webinar tomorrow

Tomorrow  I'll be giving a talk in Germany (8am California time, 17:00 in Germany), hosted by the German Health Economics Association (DGGÖ).  (Bob Slonim will be giving a talk in this series in the summer.)

My title will be Kidney Exchange to increase transplantation: around the world, and in Germany?

(One big issue is that kidney exchange isn't yet supported in Germany.) 

There is a webinar address at the above link for those who might like to listen.

Further progress on course allocation, by Budish, Gao, Othman, Rubinstein and Zhang

 Here are some new developments in the course allocation mechanism used initially in Wharton and now elsewhere.  It turns out that strategy-proofness in the (very) large doesn't imply strategyproofness in samples of realistic size, but this seems to be fixable (and profitable manipulations were not easy to find). The paper concludes with some far ranging thoughts on the econ-cs interface.

Practical algorithms and experimentally validated incentives for equilibrium-based fair division (A-CEEI)   by ERIC BUDISH, RUIQUAN GAO, ABRAHAM OTHMAN  AVIAD RUBINSTEIN, and QIANFAN ZHANG

Abstract: "Approximate Competitive Equilibrium from Equal Incomes (A-CEEI) is an equilibrium-based solution concept for fair division of discrete items to agents with combinatorial demands. In theory, it is known that in asymptotically large markets:

•For incentives, the A-CEEI mechanism is Envy-Free-but-for-Tie-Breaking (EF-TB), which implies that it is Strategyproof-in-the-Large (SP-L).

•From a computational perspective, computing the equilibrium solution is unfortunately a computationally intractable problem (in the worst-case, assuming PPAD≠FP).

We develop a new heuristic algorithm that outperforms the previous state-of-the-art by multiple orders of magnitude. This new, faster algorithm lets us perform experiments on real-world inputs for the first time. We discover that with real-world preferences, even in a realistic implementation that satisfies the EF-TB and SP-L properties, agents may have surprisingly simple and plausible deviations from truthful reporting of preferences. To this end, we propose a novel strengthening of EF-TB, which dramatically reduces the potential for strategic deviations from truthful reporting in our experiments. A (variant of ) our algorithm is now in production: on real course allocation problems it is much faster, has zero clearing error, and has stronger incentive properties than the prior state-of-the-art implementation"

Here's an intriguing passage:

"In Section 6 we use our manipulation-finding algorithm in combination with our fast A-CEEI finding algorithm to explore the plausibility of effective manipulations for students bidding in ACEEI. Originally, we had expected that since our mechanism satisfies the EF-TB and SP-L properties, it would at least be practically strategyproof — if even we don’t really understand the way our algorithm chooses among the many possible equilibria, how can a student with limited information learn to strategically bid in such a complex environment? 

"Indeed, in 2 out of 3 schools that we tested, our manipulation-finding algorithms finds very few or no statistically significant manipulations at all. However, when analyzing the 3rd school, we stumbled upon a simple and effective manipulation for (the first iteration of) our mechanism. We emphasize that although the manipulation is simple in hindsight, in over a year of working on this project we failed to predict it by analyzing the algorithm — the manipulation was discovered by the algorithm. 

"Inspired by this manipulation, we propose a natural strengthening of envy-free (discussed below), which we call contested-envy free. We encode the analogous contested EF-TB as a new constraint in our algorithm (specifically, the integer program for finding optimal budget perturbations). Fortunately, our algorithm is still very fast even with this more elaborate constraint. And, when we re-run our manipulation-finding experiments, we observe that contested EF-TB significantly reduces the potential for manipulations in practice."

...

"Conclusion:  In this work, we give a significantly faster algorithm for computing A-CEEI. Kamal Jain’s famous formulation “if your laptop cannot find it then neither can the market” [Papadimitriou 2007] was originally intended as a negative result, casting doubt on the practical implications of many famous economic concepts because of their worst-case computational complexity results. Even for course allocation, where a heuristic algorithm existed and worked in practice, Jain’s formulation seemed to still bind, as solving A-CEEI involved an intense day-long process with a fleet of high-powered cloud servers operating in parallel. The work detailed in this paper has significantly progressed what laptops can find: even the largest and most challenging real course allocation problems we have access to can now be solved in under an hour on a commodity laptop. 

"This significant practical improvement suggests that the relationship between prices and demand for the course allocation problem—and potentially other problems of economic interest with complex agent preferences and heterogeneous goods—may be much simpler than has been previously believed and may be far more tractable in practice than the worst-case theoretical bounds. Recalling Jain’s dictum, perhaps many more market equilibria can be found by laptops—or, perhaps, Walras’s original and seemingly naive description of how prices iterate in the real world may in fact typically produce approximate equilibria. 

"Our fast algorithm also opens the door for empirical research on A-CEEI, because we can now solve many instances and see how the solution changes for different inputs. We took it in one direction: empirically investigating the incentives properties of A-CEEI for the first time. For course allocation specifically, this faster algorithm opens up new avenues for improving student outcomes through experimentation. For instance, university administrators often want to subsidize some 6 group of students (e.g., second-year MBA students over first-year MBA students), but are unsure how large of a budget subsidy to grant those students to balance equity against their expectations. Being able to run more assignments with different subsidies can help to resolve this issue."

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Earlier related posts:

Thursday, April 23, 2009

Course allocation, by Eric Budish

Sunday, October 4, 2009

Course allocation by Budish, updated

Thursday, May 30, 2013

Wharton's new Course Match for MBA students to choose their classes: market design in action

Monday, August 3, 2015

Course allocation at Wharton: looking under the hood

Tuesday, June 9, 2020

Cognomos--course allocation software by Eric Budish et al.

How do (should?) economists study repugnance?

 Here's a recent paper by Peter Cserne that looks at different ways that economists study repugnance:

Cserne, P. (2023). Economic analyses of repugnant market transactions: A modest typology. Journal of Institutional Economics, 1-14. doi:10.1017/S1744137423000139

"Abstract: Economic accounts of repugnance concern two broad questions: the rationalisation of sentiments of repugnance (do emotional and visceral reactions of repugnance track valid reasons for not engaging in or condemning certain (trans)actions?) and institutional design (how to institute, regulate, or restrict markets in response to reasonable objections). If repugnance expresses valid practical reasons for regulating or limiting markets, our institutions should acknowledge and express these. If attitudes of repugnance are not rationalisable in the sense of instrumental or moral values, we should disregard or eventually counteract or reduce them. Focusing on a special case of repugnance, when commodification, i.e., the sale of goods or services for money meets societal disapproval, this paper identifies three characteristic ways to combine conceptual, empirical, and normative arguments and map repugnance into a disciplinary ‘epistemic frame’ of economics: repugnance as taste; repugnance as proxy for market failures or moral reasons; repugnance as hypocrisy or contingent cultural fact. Correspondingly, economists advise to (1) work around; (2) make sense of; and (3) explain away people's sentiments of repugnance."

...

"In recent decades, the economic discourse on repugnance has become rich and dense. While the moral limits of markets have been discussed in philosophy and various social and policy sciences for centuries, in the last decades, repugnance as a possible limit to markets has been increasingly subject to technical economic analysis as well (Khalil and Marciano, Reference Khalil and Marciano2018; Roth, Reference Roth2007; Tirole, Reference Tirole2017: 33–50). To be sure, from a longer historical perspective, economists have always been concerned with moral sentiments, including repugnance.

...

"Regarding the moral limits of markets, there is a range of (a) substantive views. For the purposes of this paper, we roughly distinguish three stances: commodification, anti-commodification, and anti-anti-commodification. These are expressed in different (b) conceptual categories: as moral preferences; moral externalities or merit goods; and hypocrisy or cultural facts. Together, they allow to express the substantive concerns in (c) analytical frameworks, in other words, they provide the technical terms for economists to, respectively: work around; rationalise, i.e., make sense of; and explain away people's repugnance. Thus, I suggest distinguishing three substantive stances on repugnance in economics, combining conceptual choices and normative commitments into analytical frameworks.

"First, economists may conceptualise repugnance as a taste or (moral) preference. Following the dictum de gustibus non est disputandum (Stigler and Becker, Reference Stigler and Becker1977), they engage in technical normative analysis and institutional design in an engineering mode (Roth, Reference Roth2002). Normatively, they orient themselves in favour of commodification, i.e., extending the scope of markets. Correspondingly, their analytical strategy is to propose policies to ‘work around’ social sentiments of repugnance.

"Second, economists may conceptualise repugnance in terms of (moral) externality or merit goods, i.e., as versions of or proxies for market failures. In doing so, they make sense of sentiments of repugnance, in terms of ordinary economic analysis. Correspondingly, they propose policies to justify limiting or regulating markets. They engage in the rationalisation of anti-commodification sentiments in terms of public reasonableness.

"Third, economists may conceptualise repugnance as an expression of hypocrisy or as a cultural fact of no independent normative weight. Normatively, they engage in demystifying repugnance either by naturalising it or philosophically debunking sentiments of repugnance as unreasonable ‘romance’; their analytical strategy could be characterised as anti-anti-commodification insofar as they aim to explain away anti-commodification arguments as irrelevant for policy debates around institutional design."

An upside to dowries, by Natalie Bau, Gaurav Khanna, Corinne Low & Alessandra Voena

 Dowries (like bride prices*) are often criticized, but may have indirect effects that aren't so easy to see, as in this recent NBER paper:

Traditional Institutions in Modern Times: Dowries as Pensions When Sons Migrate by Natalie Bau, Gaurav Khanna, Corinne Low & Alessandra Voena  NBER WORKING PAPER 31176, DOI 10.3386/w31176

Abstract: This paper examines whether an important cultural institution in India - dowry - can enable male migration by increasing the liquidity available to young men after marriage. We hypothesize that one cost of migration is the disruption of traditional elderly support structures, where sons live near their parents and care for them in their old age. Dowry can attenuate this cost by providing sons and parents with a liquid transfer that eases constraints on income sharing. To test this hypothesis, we collect two novel datasets on property rights over dowry among migrants and among families of migrants. Net transfers of dowry to a man's parents are common but far from universal. Consistent with using dowry for income sharing, transfers occur more when sons migrate, especially when they work in higher-earning occupations. Nationally representative data confirms that migration rates are higher in areas with stronger historical dowry traditions. Finally, exploiting a large-scale highway construction program, we show that men from areas with stronger dowry traditions have a higher migration response to reduced migration costs. Despite its potentially adverse consequences, dowry may play a role in facilitating migration and therefore, economic development.

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*Recall this earlier paper:

Ashraf, Nava, Natalie Bau, Nathan Nunn, and Alessandra Voena. "Bride price and female education." Journal of Political Economy 128, no. 2 (2020): 591-641.

Freakonomics replay and update on kidney exchange and organ donation

 Freakonomics Radio yesterday revisited some of their old podcasts about kidney exchange. In one, they interview me, and in another, they interview Ned Brooks, who listened to that interview and went on to become a non-directed kidney donor and to found an organization to support other kidney donors, the NKDO, National Kidney Donation Organization.  You can listen and/or read the transcript at this link:

EPISODE 209

Make Me a Match (Update)

"Sure, markets work well in general. But for some transactions — like school admissions and organ transplants — money alone can’t solve the problem. That’s when you need a market-design wizard like Al Roth. Plus: We hear from a listener who, inspired by this episode, made a remarkable decision.

"Last month, the federal government announced plans to modernize the U.S. organ-donation system. They want to speed up the process by which organ-transplant patients are matched with donated organs, and they also want to reduce racial inequities in the system. When we saw this news, we decided to go into our archive and put together the episode you’re about to hear. It’s a mashup of a 2015 episode, No. 209, called “Make Me a Match,” and a portion of a 2016 episode, No. 237, which includes a personal story from a listener who was inspired by that earlier episode to make a remarkable decision. All the relevant facts and figures have been updated. As always, thanks for listening."

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Here are my previous posts on Freakonomics episodes.