Tuesday, December 21, 2021

Report from Dagstuhl: Matching Under Preferences: Theory and Practice, Edited by Haris Aziz, Péter Biró, Tamás Fleiner, and Bettina Klaus

 Matching theory was alive and well during the pandemic. Here's a report of the (partially in person) Dagstuhl Seminar, July 25–30, 2021 – http://www.dagstuhl.de/21301

Report from Dagstuhl Seminar: Matching Under Preferences: Theory and Practice, Edited by Haris Aziz, Péter Biró, Tamás Fleiner, and Bettina Klaus

"This report documents the program and the outcomes of Dagstuhl Seminar 21301 “Matching Under Preferences: Theory and Practice”. The seminar featured a mixture of technical scientific talks, survey talks, open problem presentations, working group sessions, five-minute contributions (“rump session”), and a panel discussion. This was the first Dagstuhl seminar that was dedicated to matching under preferences.    

...

"The seminar was conducted in a hybrid manner, with 15 participants attending the seminar physically from the Dagstuhl center and 34 participants attending online.

...

"The four main focus topics of the workshop were the following ones.

1. Matching markets with distributional constraints,

2. Probabilistic and Fractional Matching,

3. Matching in online and dynamic settings, and

4. Matching Markets and machine learning."

***********

As a sign of the times, this non-technical working group session caught my eye:

"4.1 Gender Terminology in Bipartite Stable Matching

Robert Bredereck (HU Berlin, DE) License Creative Commons BY 4.0 International license © Robert Bredereck

"Bipartite Stable Matching is classically presented as “Stable Marriage” with one side being men and the other side being women. Meant as illustration and not as proposal for real marriage, the many successful applications of the model are all in completely different domains. The classical terminology, however, can be easily misunderstood and becomes questionable at latest when one side behaves always passive while the other behaves always active, one site manipulates while the other is honest, there is external manipulation, or some couples are forced or forbidden.

"Participants of the seminar discussed the seriousness of these issues in particular in situations where people from outside the community are involved (teaching, grant proposals, etc.). To avoid misunderstanding many participants are using alternative terminologies:

"sportsmen ↔ sportswomen (mixed teams such as tennis)

"leaders ↔ followers (dancing)

"doctors ↔ hospitals

"student ↔ colleges

"workers ↔ companies

"workers ↔ apprentices

"mentors ↔ mentees

"While some of the alternatives even allow to keep using different grammatical gender for the two sides (and so allow to write easily comprehensible texts), other alternatives fit better with the manipulation setting. Some of these alternative terminologies are already established in more specialized or generalized settings of Stable Matching, but may still qualify for the illustration of Bipartite Stable Matching. Another possibility in use is to keep the marriage market terminology while clearly putting it into a historical context."

*****

I've used many of these terms when describing matching, but I wonder if "leaders" and "followers" in the context of dancing will solve the problem that this discussion of terminology is aimed at...



Monday, December 20, 2021

Better LAT than never: Living Apart Together for older romantic relations

 Marriage is not the only way that people can romantically partner, and of course young people are the pioneers in many new forms of household formation.  But here are two news stories that say Living Together Apart (LAT) relationships are growing among older and often previously married couples.

The NY Times has a story focusing on older couples:

Older Singles Have Found a New Way to Partner Up: Living Apart. Fearing that a romantic attachment in later life will lead to full-time caregiving, many couples are choosing commitment without sharing a home. By Francine Russo

"With greater longevity, the doubling of the divorce rate since the 1990s for people over 50 and evolving social norms, older people like Ms. Randall are increasingly re-partnering in various forms. Cohabitation, for example, is more often replacing remarriage following divorce or widowhood, said Susan L. Brown, a sociologist at Bowling Green State University in Ohio.

...

"As researchers study those who do partner, however, they find that increasing numbers are choosing a kind of relationship known as LAT (rhymes with cat), for “living apart together.” These are long-term committed romantic relationships without sharing (or intending to share) a home.

"“A big attraction of LAT is to avoid the potential responsibility of being a full-time caregiver,” said Ingrid Arnet Connidis, an emerita sociology professor at Western University in London, Ontario. “Women cared for their children, parents and spouse, and want to avoid getting into these traditional gender roles.”

"While researchers have not yet delved deeply into the demographics of those in LAT relationships, anecdotally it seems to be more prevalent among those at high enough socioeconomic levels to be able to maintain separate households. In general, there is evidence that wealthier people who are single later in life are more likely to re-partner."

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

The WSJ has a story focusing on new couples in the midst of raising kids:

The Secret to These Successful Marriages? Living Apart. The number of married couples who live apart is small but growing. Here’s how they say the arrangement helps their families and their relationships   By Clare Ansberry

"Many couples who live apart have been married before and don’t want to uproot their children from homes, schools and friends, or can’t because of joint-custody arrangements.

...

"The number of married people living apart, which includes military couples, is still small but rose 4.8% in the last decade to 3.6 million, according to figures from the Census Bureau."

Sunday, December 19, 2021

An Interview Match for medical residents and fellows--a preliminary proposal

 There is a lot of concern in the graduate medical education community that too much time and treasure is being spent on too many unproductive interviews prior to the submission of rank order lists for the Match.  Here's discussion of a proposal for an interview match, to precede the interview stage before the actual NRMP Match.

Explaining a Potential Interview Match for Graduate Medical Education, by Irene Wapnir, MD; Itai Ashlagi, PhD; Alvin E. Roth, PhD; Erling Skancke, MS; Akhil Vohra, PhD; Irene Lo, PhD; Marc L. Melcher, MD, PhD, J Grad Med Educ (2021) 13 (6): 764–767.  https://doi.org/10.4300/JGME-D-20-01422.1

"Residency and fellowship candidates are applying to more programs to enhance their chances of securing interviews and matching favorably. The COVID-19 pandemic has shifted interviews to video formats, which lowers interview-associated costs for applicants but may further increase application numbers.1  While a candidate's application to a training program communicates some interest in the program, the relative amount of interest is obscured when candidates apply to large numbers of programs. We suspect that, as a result, programs host large numbers of low-yield interviews.

"The number of interviews is steadily increasing, and there is widespread agreement on the need to ease congestion in the pre-Match evaluation process.2  Proposals to reduce this burden include signaling (organized, centrally-controlled protocol for limited communication of interest),3–5  capping the number of applications or the number of interviews,6,7  and an early acceptance matching program as in college admissions.8,9 

"We propose another solution, an “interview match” to address the expanding number of interviews.10  An interview match enables candidates and programs to express preferences privately by ranking their interview choices individually or in tiers. This may ease congestion in the “marketplace,” reduce costs for candidates, favor interviews that are more likely to lead to a match in the final Match, and avoid interviews unlikely to convert to a match. An interview match algorithm would match based on the same “deferred-acceptance” algorithm currently used by the National Resident Matching Program but adapted to a “many-to-many” setting where candidates and programs receive multiple interviews."

Saturday, December 18, 2021

70: three score years and ten

 If you persist, you find that 70 isn't nearly as old as you once imagined it to be (and  as it used to be, maybe not even that long ago). Certainly three score years and ten is no longer an inspirationally long life.

(The Hebrew verse 10 of Psalm 90 simply says "70 years." I think that "three score and ten" is a flourish originally introduced in the King James translation.

יְמֵי-שְׁנוֹתֵינוּ בָהֶם שִׁבְעִים שָׁנָה

"The days of our years are threescore years and ten, or even by reason of strength fourscore years...")


Earlier this month I was surprised at what I thought would be only a Hanukkah party, by a pre-birthday celebration in which a number of my students located a pretty big group of my former students and postdocs to produce this video of birthday greetings and reminisces. 

I've been lucky in my students and young colleagues, long ago and still today.  Thanks to Alex and the local gang, to all those on the video, and to all those who weren't found by the surprise team, who are all remembered fondly and gratefully...

Friday, December 17, 2021

One Hundred Years of Game Theory: Nobel Symposium in Stockholm

 I'm in Stockholm for a celebration of the 100th anniversary of Emile Borel's 1921 paper on Game Theory.

It's a three day conference, Friday through Sunday, but I gather that only Sunday will be publicly available on Zoom.

Here's the schedule for all three days:

NOBEL SYMPOSIUM “ONE HUNDRED YEARS OF GAME THEORY”, DECEMBER 17-19, 2021

My talk is on "Game theory and economic engineering: Dealing with big strategy sets, including invention of new strategies"

And here's the announcement and Zoom link for Sunday, Dec 19 (the day Borel's paper was presented in 1921)

One Hundred Years of Game Theory: Future Applications and Challenges

"On December 19, 1921, the mathematician Emile Borel published a paper which laid the foundation of game theory. He offered a new framework for analysis in economics, political science, and other social and behavioral sciences. The centennial of this publication is a good occasion to ask where we may look today for the next breakthroughs that will be important for future economics and other social sciences, and for biology and computer science. What are the most promising directions for application? What are the most important challenges?

Start time: 2021-12-19 at 14:30

End time: 2021-12-19 at 16:30

Location: via Zoom. Link will be sent to the email address provide in the registration form."

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

I hear that some of the scheduled speakers who expected to come in person on Sunday will, at the last minute, not be able to do so, due to various outbreaks of Covid, particularly at Cornell.  Fortunately we've become good at using Zoom...

Thursday, December 16, 2021

Muriel Niederle wins the Austrian Käthe-Leichter-Preis for "outstanding achievements in the field of social, human and cultural sciences"

 Here's the announcement (with help from Google Translate):

Lifetime Achievement Prize goes to Edeltraud Hanappi-Egger (WU), Käthe-Leichter State Prize to Christine Zulehner (University of Vienna) and Muriel Niederle (Levin Endowed Professorship in Stanford)

"Vienna (OTS) - The Käthe-Leichter State Prize for women's studies, gender research and equality in the world of work honors outstanding achievements in the field of social, human and cultural sciences.

"Women's Minister Susanne Raab presented this year's prizes on Wednesday: The Lifetime Achievement Prize went to Dr Edeltraud Hanappi-Egger, who works at the Vienna University of Economics and Business, and the Käthe-Leichter State Prize to Dr Christine Zulehner, who works at the university Vienna, and to Dr. Muriel Niederle, who teaches at Stanford University."

Wednesday, December 15, 2021

Virtual interviewing increased the number of interviews by (and of) candidates for medical residencies

 Here's an article on virtual interviewing of candidates for medical residencies (about which, see also this post about Erling Skancke's work on interviewing):

Beshar I, Tate WJ, Bernstein D. Residency interviews in the digital era, Postgraduate Medical Journal Published Online First: 05 October 2021. doi: 10.1136/postgradmedj-2021-140897

"Halfway through the interview cycle, however, questions were raised about system-level equity of virtual interviewing. In December 2020, the Association of American Medical Colleges (AAMC) released an open letter citing ‘a maldistribution in residency interview invitations’, with the ‘highest tier applicants hav(ing) so many interviews’.15 The letter, addressed to both programme directors and students, called on programmes ‘to recruit a diverse pool of residents’ and encouraged students ‘to release[e] some interviews if you are holding more than needed, allowing your fellow students to access those interview opportunities’.15 Medical school deans began encouraging competitive students to forgo interviews. In the words of the Dean of students at the UC College of Medicine: ‘They need to identify a reasonable number to have a successful match and release others so their peers who need them can have them’.6 By some estimates, programmes invite the same pool of highly qualified applicants, with just 7%–21% of the applicant pool filling 50% of the interview slots in some specialties.16 Meanwhile, a survey of plastic surgery programme directors demonstrated nearly one in three increased the number of interview offers per available residency spot.

"At our institution—Stanford School of Medicine—and as applicants of the 2020–2021 cycle ourselves—we saw the effect of this firsthand. We administered a survey to all students participating in the match process in both the 2019 (in-person) and 2020 (virtual) years. In the survey, respondents identified the residency programme or programmes to which they applied as well as the number of interviews they attended. Of Stanford’s 2019 and 2020 graduating classes, 83.7% (n=72) and 62.3% (n=62), respectively, completed our survey.

"Of the 2019 applicants, 97.2% (n=70) reported residency interviews that required airline travel, compared with 0% of the 2020 applicants. The median number of interviews for the 2019 applicants was 8, compared with 14 for the 2020 applicants. Across the 2 years analysed, all fields showed an increase in the number of interviews accepted (table 1). Of the four fields with the most applicants, the largest per cent change was in anaesthesia (244%), followed by ophthalmology (216%), internal medicine (144%) and psychiatry (128%), respectively. On average, across all specialties, the number of accepted interviews changed by 160%.





Tuesday, December 14, 2021

The costs of deceased donor organ recovery in the U.S., by Held et al. in the journal Transplantation

 Here's the report of an investigation into organ procurement costs and finances:

Cost Structures of US Organ Procurement Organizations by Held, Philip J. PhD1; Bragg-Gresham, Jennifer L. PhD2; Peters, Thomas G. MD3; McCormick, Frank PhD4; Chertow, Glenn MD, MPH1; Vaughan, William P. BS5; Roberts, John P. MD, Transplantation. 2021;105(12):2612-2619. doi:10.1097/TP.0000000000003667.

Abstract: "Background. The goal is to provide a national analysis of organ procurement organization (OPO) costs.

"Methods. Five years of data, for 51 of the 58 OPOs (2013-2017, a near census) were obtained under a FOIA. OPOs are not-for-profit federal contractors with a geographic monopoly. A generalized 15-factor cost regression model was estimated with adjustments to precision of estimates (P) for repeated observations. Selected measures were validated by comparison to IRS forms.

"Results. Decease donor organ procurement is a $1B/y operation with over 26 000 transplants/y. Over 60% of the cost of an organ is overhead. Profits are $2.3M/OPO/y. Total assets are $45M/OPO and growing at 9%/y. "Tissue" (skin, bones) generates $2-3M profit/OPO/y. A comparison of the highest with the lower costing OPOs showed our model explained 75% of the cost difference. Comparing costs across OPOs showed that highest-cost OPOs are smaller, import 44% more kidneys, face 6% higher labor costs, report 98% higher compensation for support personnel, spend 46% more on professional education, have 44% fewer assets, compensate their Executive Director 36% less, and have a lower procurement performance (SDRR) score.

"Conclusions. Profits and assets suggest that OPOs are fiscally secure and OPO finances are not a source of the organ shortage. Asset accumulation ($45M/OPO) of incumbents suggests establishing a competitive market with new entrants is unlikely. Kidney-cost allocations support tissue procurements. Professional education spending does not reduce procurement costs. OPO importing of organs from other OPOs is a complex issue possibly increasing cost ($6K/kidney)."

...

"CONCLUSION

"In the United States, deceased-donor organ recovery costs total $1B per year and represent approximately one-third the cost of an organ transplant procedure. Direct and indirect costs are reported on CMS required OPO cost reports, confirming that over half of all costs are indirect, such as the costs of organ procurement personnel, professional education, and other personnel expenses. Kidney cost increases over the 5-y study period seem reasonable compared with all medical care cost increases but increased at rates in excess of the cost increases transplant centers experienced for transplant procedures. And, kidney importation (from other OPOs) adds substantially to cost adding $4K-$6K per organ. OPO revenue over expense is largely due to profits from tissue recovery activities. Cost variations of over 100% across areas suggest less than socially efficient cost controls. The strong financial position of OPOs suggests that fiscal limits are not a likely explanation for the shortage of organs for transplantation.

"In considering individual OPOs, 2 levels of kidney costs (>$40K/kidney and <$40K) disclosed both statistically and clinically significant differences. The highest-cost OPOs (>$40K/kidney) are associated with higher direct costs (including more imported organs), higher compensation for support staff and procurement coordinators, higher professional education spending, and lower total assets, fewer organs procured, and lower performance measures-among other factors. Assessment of structural factors such as these may lead to opportunities to decrease cost and improve efficiencies. The US OPO enterprise is substantial, yet future OPO efficiency and performance improvements through competition appear unlikely considering OPO assets, current practices, and regulatory oversight issues. The inefficient financial incentives built into the U.S. OPO structure include both monopoly markets and self-reported cost reimbursement. These characteristics do not compel critical assessment, which could lead to organizational changes and more effective mission capability."

Monday, December 13, 2021

Working remotely may lessen income inequality between men and women: Claudia Goldin in the WSJ

 Here's Claudia Goldin in the WSJ, on how income inequality between men and women may be lessened by the growth of remote work. (She argues that women pay a price for flexible hours, since the highest paying jobs are "greedy" for long and on-call work.)

How the Pandemic Could Make the Future Brighter for Women in the Workplace. It could lead to less gender inequality at work, and more equity at home By Claudia Goldin Dec. 11, 2021

"Whereas the job with flexible hours paid far less than the greedy job before the pandemic, previously greedy jobs are now more flexible and the previously flexible jobs are now more productive. The working couple with children can now have a more equitable household without giving up as much income. The on-call parent will be able to compete for the previously greedy job, and employers will expand the previously flexible jobs, because these jobs have become more productive. As a result, the difference between the wages of the previously greedy and previously flexible jobs will narrow.

"Consider the mergers-and-acquisition work that once had to be done in Tokyo, or the contract that needed to be signed in Zurich. They actually don’t need to be done in person, we have learned. The on-call, at-home parent, generally the mother, hadn’t been able to do these transactions. But now they can be accomplished without being away during the evening and without flying across an ocean. The flexible job has become more productive and the greedy job has become more flexible."

Sunday, December 12, 2021

What we know about labor market interviews

 Erling Skancke is on the job market from Stanford this year. You should interview him. If you do, you'll learn a lot about interviews, which are the subject of his job market paper, which provides a lot of new insight into an important practical set of isssues.

Skancke, Erling, Welfare and Strategic Externalities in Matching Markets with Interviews (November 10, 2021). Available at SSRN: https://ssrn.com/abstract=3960558 or http://dx.doi.org/10.2139/ssrn.3960558

Abstract: Recent debate in the medical literature has brought attention to issues with the pre-match interview process for residency and fellowship positions at hospitals. However, little is known about the economics of this decentralized process. In this paper, I build a game-theoretic model in which hospitals simultaneously decide on which doctors to interview, in order to learn their preferences over doctors. I show that increased interview activity by any hospital imposes an unambiguous negative welfare externality on all other hospitals. In equilibrium, both hospitals and doctors may be better off by a coordinated reduction in interview activity. The strategic externality is more subtle, and conditions are derived under which the game exhibits either strategic complementarities or substitutes. Moreover, an increase in market size may exacerbate the interview externalities, preventing agents from reaping the thick market benefits that would arise in the absence of the costly interviews. This effect increases participants' incentives to match outside of the centralized clearinghouse as markets become thicker, jeopardizing the long-term viability of the clearinghouse. The model also provides new insights into several market design interventions that have recently been proposed.

Saturday, December 11, 2021

Disrupting black markets: call for papers

 Laws banning markets often create black markets. And the same technologies that facilitate legal markets may do so for illegal markets that we would like to extinguish, e.g. involving human trafficking, trade in endangered species or drugs, ransomware, etc.

How can we control such markets?

Here's a call for papers:

Call for Papers , Annals of Operations Research 

Special Issue: Applications of Operations Research and Data Science in Disrupting Illicit Markets 

Guest Editors: Mahdi Fathi, University of North Texas, TX, USA, mahdi.fathi@unt.edu 

Panos M. Pardalos, University of Florida, FL, USA, pardalos@ufl.edu 

Dursun Delen, Oklahama State University, OK, USA, dursun.delen@okstate.edu 

Stefan Gold, University of Kassel, Germany, gold@uni-kassel.de

 Marzieh Khakifirooz, Tecnologico de Monterrey, Mexico, mkhakifirooz@tec.mx 

Full paper submission deadline: 31 August 2022 

Friday, December 10, 2021

The first children with germline-edited genomes are growing up: the CRISPR story so far

 Nature has the story:

The CRISPR children.  In China, the first children with germline-edited genomes are growing up.  by Vivien Marx

"Three years ago, the world was in uproar after a journalist broke the news about two babies born with genomes edited with CRISPR-Cas9. He Jiankui had been invited to speak in the session on human embryo editing at the Second International Summit on Human Gene Editing. Some of He’s advisors thought he should speak about the twins, while others advised him to wait until his manuscripts were published, and He was purportedly leaning toward focusing just on preclinical work. Then, when the news of the twins’ birth was revealed, he adjusted existing slides to address the news.

....

"The goal of these heritable gene edits was to generate HIV-resistant people, by introducing germline mutations into the C-C chemokine receptor type 5 (CCR5) gene, which encodes a co-receptor for HIV. This thinking was roundly criticized by researchers and ethicists because of a lack of a medical need given the availability of antiretroviral treatments.He’s rationale for germline editing was that the gene was well studied, that HIV remains a devastating disease and that HIV infection status leads to discrimination. The participants in this study were HIV-discordant couples: the wives are HIV negative and their husbands are HIV positive and being treated with antiretroviral drugs.

...

"As the chorus of criticism around the experiments mounted in the days after the announcement, He disappeared from public view. Some assumed he was given a kind of escort who accompanied him around campus and monitored him. In January he was fired from his university post, and apparently detained some time thereafter.The Chinese authorities initially touted He’s achievement, then backtracked, condemned the work and shuttered the lab. After a trial in Nanshan District People’s Court behind closed doors, He was sentenced to a fine and three years in jail for ‘illegal medical practice’, along with two members of his team.

...

"One key concern for the children is genetic mosaicism—a condition in which different cells from the same individual have different genomes. Such conditions can occur naturally during development, for example through post-zygotic mutations, when mitosis proceeds irregularly and mutated cells persist. It can also happen when, after an environmental insult, a DNA break is not properly repaired.

...

"Whitehead Institute researcher Rudi Jaenisch says that mosaicism is a major problem with current approaches to heritable embryo editing. When genome edits take place after a zygote has become a two-cell or multicellular blastocyst—as likely occurred in He’s experiments—the edited and unedited cells keep dividing.

...

"Adashi fears that, given how imperfect the gene-editing tools are, the type of genetic and genomic “mayhem” that can result might lead to the loss of entire chromosomes or pieces of them. “Basically they could have a scrambled genome,” he says about the girls. He points to several papers showing such damage when CRISPR-Cas9-based gene editing is performed in human embryos.

...

"Rather than edit embryos, both Jaenisch and Church think that if germline gene editing is ever considered, it would be more promising to, for example, edit spermatogonial stem cells that give rise to sperm. But for now neither heritable gene editing in embryos nor germ-cell editing are considered ready for application in people.

"What happened in He’s lab, says Musunuru, is a textbook ethics violation that should be extensively analyzed and discussed. To date, the manuscripts describing the work that led to the gene-edited children have not been published in a journal or placed on a preprint server (Box 2). But since the birth of Lulu, Nana and Amy, a host of reports about the safety and ethics of gene editing have been published.

...

"They may well grow up healthy, says Adashi. Considering the risks endured in their creation, that would be a wonderful outcome. But he worries that germline gene editing “has a significant potential to cause harm rather than good.”

“How and if it will manifest is unknown,” he says. It’s certainly no way “to start life.”

***********

Earlier:

Monday, December 14, 2015

Thursday, December 9, 2021

Celebration of Marilda Sotomayor, livestreamed today

 Tribute to Marilda Sotomayor

Date and time: December 9th, 2021. From 14:00 to 16:15 Brazil time (GMT -3:00) (i.e. 9am to 11:15am Pacific time today)

Here's the program (and the video recording is below):

1) 14:00 - Session opening Prof. Wilfredo L. Maldonado (FEA - Universidade de São Paulo)

2) 14:05 - Academic career of Marilda Sotomayor - early friend account  Prof. Aloisio Araujo (Getulio Vargas Foundation – EPGE/RJ and IMPA)

3) 14:20 - Constrained-optimal tradewise-stable outcomes in the one-sided assignment game: A solution concept weaker than the core  Prof. Jesús David Pérez Castrillo (Universitat Autónoma de Barcelona and BSE)

4) 14:55 - Interior points of the core; Two different approaches Prof. Myrna Wooders (Vanderbilt University)

5) 15:30 - Stable and almost stables matching in centralized and decentralized markets Prof. Alvin Roth (Stanford University)

6) 16:05 - Acknowledgement and session closure Prof. Maurício Bugarin (Universidade de Brasília)


x

49º Encontro Nacional de Economia - Sessão Especial Homenagem a Marilda Sotomayor

 

Wednesday, December 8, 2021

Dating and Search: who should propose? by Yash Kanoria and Daniela Saban

 Dating sites are often congested, with many of them having more men than women. Here's an analysis suggesting that there are efficiency gains to having the short side of the market (in this case the women) do most of the search, by requiring them to initiate contact...

Facilitating the Search for Partners on Matching Platforms by Yash Kanoria , Daniela Saban, Management Science, Published Online:19 May 2021 https://doi.org/10.1287/mnsc.2020.3794

Abstract: Two-sided matching platforms can control and optimize over many aspects of the search for partners. To understand how matching platforms should be designed, we introduce a dynamic two-sided search model with strategic agents who must bear a cost to discover their value for each potential partner and can do so nonsimultaneously. We characterize evolutionarily stable stationary equilibria and find that, in many settings, the platform can mitigate wasted search effort by imposing suitable restrictions on agents. In unbalanced markets, the platform should force the short side of the market to initiate contact with potential partners, by disallowing the long side from doing so. This allows the agents on the long side to exercise more choice in equilibrium. When agents are vertically differentiated, the platform can significantly improve welfare even in the limit of vanishing screening costs by forcing the shorter side of the market to propose and by hiding information about the quality of potential partners. Furthermore, a Pareto improvement in welfare is possible in this limit.

*******

Earlier:

Thursday, February 13, 2020

Tuesday, December 7, 2021

The demise of bourbon-scented hand sanitizer

The Covid pandemic isn't over, but the emergency shortage of hand sanitizer is.

Some Companies Will Stop Making Alcohol-Based Hand Sanitizer, by Rebecca Voelker, JAMA. 2021;326(19):1899. doi:10.1001/jama.2021.19919

"Nearly 2 years after the COVID-19 pandemic struck the US, the FDA will withdraw its guidance on manufacturing hand sanitizer. The withdrawal applies to nonpharmaceutical companies that followed temporary policies to produce both alcohol-based hand sanitizer and the alcohol used in them during the public health emergency.

"“In recent months, the supply of alcohol-based hand sanitizer from traditional suppliers has increased, and now, most consumers and healthcare personnel are no longer having difficulty obtaining these products,” Patrizia Cavazzoni, MD, director of the FDA’s Center for Drug Evaluation and Research, explained in a statement.

"The agency’s announcement stated that companies making alcohol-based hand sanitizer under the temporary policies must stop production by December 31. Those that plan to continue making the product will have to comply with requirements for over-the-counter topical antiseptics as well as the FDA’s Current Good Manufacturing Practice regulations."

***********

Earlier:

Thursday, June 11, 2020

Monday, December 6, 2021

Deceased organ allocation in the U.S., moving towards a more continuous system--Martha Pavlakis in Transplantation

 In the latest issue of Transplantation a clear description of how the transplant community is planning to move towards a more continuous way of allocating organs, in ways that have already begun (so that e.g. a lung transplant candidate in Manhattan won't be ineligible for a kidney from a deceased donor across the river in New Jersey).  One element of this that worries me is that a weighting system for priorities will be derived from focus groups of interested parties, using the Analytic Hierarchy Process, which is an orderly, matrix based process for aggregating opinions that doesn't have any ability to integrate different aspects being evaluated from the point of view of how they might effect relevant transplant outcomes, or consider how they might influence incentives for diagnosis and treatment. So I anticipate that organ allocation will continue to be in motion for the foreseeable future.

Continuous Distribution in Organ Allocation: Stepping Back From the Edge  by  Martha Pavlakis,  Transplantation: December 2021 - Volume 105 - Issue 12 - p 2517-2519, doi: 10.1097/TP.0000000000003886

"Organ allocation priorities are determined according to policies developed by the Organ Procurement and Transplantation Network (OPTN), which is operated by United Network for Organ Sharing (UNOS). In 2016, a significant shift began which will culminate in a transition of all organ allocation to be determined in the framework of an approach known as continuous distribution. The most reductive description of the change from current allocation to continuous distribution is that it will change from a classification-based (or bucket-based) system to a points-based system without hard borders. 

...

"The removal of hard boundaries in the continuous distribution system of allocation has been reviewed elsewhere6,7 and is best described by outlining the steps in its development. The steps include (1) identifying and categorizing candidate attributes; (2) building of a rating scale that assigns values for each attribute, such as candidate blood type, using UNOS and SRTR data; and (3) assigning weights to each attribute to determine how much that attribute will contribute to the candidate’s final score. This process has several parts: first, there needs to be a specific weight assigned to each attribute such that it can be prioritized against each of the other attributes. As a next step, the attributes need to be converted into points. (4) A framework will be built where a composite score is determined by combining weights and rating scales. To do this, a sensitivity tool called the analytic hierarchy process (AHP) will inform the development of the framework through a prioritization exercise.8 In these exercises, participants compare 2 attributes against each other and select their level of importance when considering a candidate for organ transplant. The information from multiple rounds of these exercises will be used to inform the weight of each attribute to the overall score. The AHP method was chosen because it has been used effectively by other healthcare groups to involve patients in making clinical decisions.9 The “participants” in this AHP method are the same participants that engage in public comment for policy change—member centers, individuals, OPOs, organizations with a vested interest in transplant such as the American Society of Transplantation, and the general public. Participants will weigh the trade-offs between effectiveness/benefit and medical urgency. Using focus groups, Oedingen et al convincingly highlighted the importance of preference studies to elucidate public preferences in organ allocation, which has multiple and sometimes competing goals.10

"Once the community has agreed on a proposed continuous distribution system, the SRTR will perform modeling to identify any potential unintended consequences of the proposal. The modeling will estimate the benefits of the new proposal and inform any needed improvements. (5) After considering community input through public comment, modeling and analysis, and committee project work, the kidney committee will then propose a composite score as a policy proposal. (6) Finally, a policy proposal will be presented to the OPTN Board of Directors for approval. Once approved, implementation of the policy is projected to take approximately 12 mo due to programming changes and education for the transplant community."

Sunday, December 5, 2021

Organ shortages for transplantation: Pig kidneys won't be transplanted into people soon

 Here's an article in Medpage Today by the chief medical officer at UNOS, pointing out that xenotransplantation is not going to substitute in the near term for other efforts to increase organ transplants. (The article goes on to discuss recent progress in other directions.)

A Look at Pig Kidneys in the Broader Transplantation Puzzle— Advancements across the field are accelerating in real time  by David Klassen, MD November 29, 2021

"Last month's breaking news that the kidney of a pig functioned normally when attached for 54 hours to the body of a brain-dead patient was hailed as an eventual solution for more than 100,000 people nationwide who are waiting for life-saving organs. While xenotransplantation, or animal-to-human transplantation, has been undergoing study and experimentation for quite some time, this was a huge step in the right direction.

As first reported on October 18, the team at NYU Langone Health obtained consent from the ventilated donor's family to attach a pig kidney to her upper leg and monitor the results. They reported that the organ, which came from an animal whose genes had been modified to avoid early rejection by a human host, began to work almost immediately and produce urine and function as would a human kidney. The pig kidney functioned normally throughout the 54-hour trial.

...

"Unfortunately, the next steps remain incredibly complex. Routine xenotransplantation of non-human organs into human bodies is many years away. One of the greatest hurdles is immunological: getting non-human organs to survive long-term, not just for a 54-hour trial. Due to the need for additional research and testing, it is unlikely that xenotransplantation will arrive in time to help most of those currently on the transplant waitlist, including more than 90,000 kidney transplant candidates."

Saturday, December 4, 2021

Morse lecture at INFORMS next year: market design and the study of operations

 In 1974, the year I received my Ph.D. from Stanford's (then) Department of Operations Research, it was unclear in what discipline game theory would best thrive.   As disciplinary boundaries shifted, I found that I was an economist.  But I've kept open my professional ties to OR, and indeed I think of market design as the engineering part of game theory, and very concerned with the operational detail of markets and marketplaces. So I was glad to accept an offer to compose a lecture on this for an OR audience, since market design is now a multi-disciplinary field that draws many students of operations.

Here's an announcement that includes the following:

Philip McCord Morse Lectureship Award

The Lectureship is awarded in honor of Philip McCord Morse in recognition of his pioneer contribution to the field of operations research and the management sciences. The award is given in odd-numbered years at the Annual Meeting if there is a suitable recipient. The term of the lectureship is two years. The award is $2,000, a certificate, a travel fund of $5,000, a copy of Morse's autobiography, In at the Beginnings: A Physicist's Life, and a copy of Morse and Kimball's Methods of Operations Research. Learn more about the Philip McCord Morse Lectureship Award and how to be nominated on the INFORMS website.

This year, the lectureship is awarded to:

Alvin E. Roth, Stanford University

Who exemplifies the true spirit of Professor Morse and who, like Morse, has been an outstanding spokesperson for the operations research profession in operations research tools and ideas in designing efficient markets for a range of applications. This award is given by the Institute for Operations Research and the Management Sciences in honor of Philip McCord Morse, in recognition of Professor Morse's pioneering contributions to the field of operations research and of his devoted service to the field's professional societies.

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See also

Tuesday, January 17, 2017

Friday, December 3, 2021

Sale of dinosaur fossils

 National Geographic has the story:

The controversial sale of 'Big John,' the world's largest Triceratops. The fossil's $7.7-million sale has some experts worried that ancient bones' rising prices will put more scientifically valuable fossils out of reach.  BYMICHAEL GRESHKO

"The founder of a South Dakotan firm called PaleoAdventures, which digs up fossils for commercial sale, Stein nicknamed the fossil “Big John” after the owner of the ranch where he found it. For six years, he held on to the Triceratops in hopes that a U.S. museum would purchase it—but none came forward. Then, in 2020, he sold the fossil to an Italian firm that prepared it for auction. With much fanfare and a jaw-dropping sale price of $7.7 million (6.65 million euros) to an anonymous buyer last month, Big John became a big deal—and added fuel to an ongoing, thorny debate among scientists, auctioneers, commercial paleontologists, and private landowners.

...

"Big John is one of more than 100 known fossils of Triceratops, one of the most common dinosaurs found in western North America’s Hell Creek Formation, which snakes through parts of Montana, North Dakota, South Dakota, and Wyoming.

"In the United States, only researchers with government permits can collect fossils on the millions of acres of federal lands, and these remains must be held in the public trust at institutions such as museums. However, fossils found on private land—including Big John—belong to the landowner and can be bought and sold legally.

"The U.S. is one of only a few countries that allows this sort of trade. In Alberta, Canada, for instance, fossils found in that province can’t be exported according to a 1970s law that designates fossils as part of Alberta’s natural heritage—a legal response to decades of foreign museums removing exquisite dinosaur fossils from the province. Other fossil-rich countries, such as Brazil, China, and Mongolia, have similar laws, though black markets dealing in fossils from these countries persist.

"Academic paleontologists have a range of views on the legal fossil trade, from begrudging acceptance to steadfast opposition. University of Calgary paleontologist Jessica Theodor, president of the Society of Vertebrate Paleontology (SVP), which represents paleontologists around the world, says she’s worried that auctions turn fossils into luxury collectibles and further legitimize the global fossil trade."

Thursday, December 2, 2021

Supervised drug injection sites open in NYC

 The NY Times has the story:

Nation’s First Supervised Drug-Injection Sites Open in New York. During the first official day in operation at the two Manhattan facilities, trained staff reversed two overdoses, officials said.  By Jeffery C. Mays and Andy Newman

"New York, the country’s most populous city, became the first U.S. city to open officially authorized injection sites — facilities that opponents view as magnets for drug abuse but proponents praise as providing a less punitive and more effective approach to addressing addiction.

"Other cities including Philadelphia, San Francisco, Boston and Seattle have taken steps toward supervised injection but have yet to open sites amid debate over the legal and moral implications of sanctioning illegal drug use.

...

"Mayor Bill de Blasio began championing safe injection sites in 2018, citing their use and success in European and Canadian cities. The decision to officially allow the sites to open comes during the mayor’s last few weeks in office and as he considers a run for governor. He said in a statement that the decision will show other cities that “after decades of failure, a smarter approach is possible.”

"The mayor also sent a letter to the providers promising “not to take enforcement action” against their operations. Four of the city’s five district attorneys — excluding only the Staten Island district attorney, Michael McMahon — support supervised drug sites."