School choice with outside options , by Akbarpour, Kapor, Neilson, van Dijk, and Zimmerman in J.Pub.E.

 One of the differences between market design and the theoretical mechanism design literature is that in mechanism design, the theorist creates the whole universe of strategies available to participants, while in practical market design, the marketplace being designed is part of some larger economic environment, which gives the participants potentially bigger strategy sets.

Here's a paper that takes that point of view with respect to school choice. In the empirical part of the paper, a switch from a manipulable immediate acceptance algorithm to a strategy proof  deferred acceptance algorithm influences families with an outside option (a guaranteed continuation in the school where they are enrolled in pre-kindergarten) differently from families without that safe option.  When the manipulable algorithm is used, families without an outside option often find it too risky to compete for scarce spaces in the most desirable schools, which they can safely do when the strategy proof algorithm is employed.

Centralized School choice with unequal outside options by Mohammad Akbarpour, Adam Kapor, Christopher Neilson, Winnie van Dijk, Seth Zimmerman, Journal of Public Economics, Volume 210, June 2022, 104644

Abstract: We study how market design choices exacerbate or mitigate pre-existing inequalities among participants. We introduce outside options in a well-known school choice model, and show that students always prefer manipulable over strategy-proof mechanisms if and only if they have an outside option. We test for the proposed relationship between outside options and manipulability in a setting where we can identify students’ outside options and observe applications under two mechanisms. Consistent with theory, students with an outside option are more likely to list popular, highly-rated schools under the Boston mechanism, and this gap disappears after switching to a Deferred Acceptance mechanism.

*******

Related earlier posts:

Monday, January 28, 2019

School choice in New Haven: studied by Kapor, Neilson and Zimmerman and switching from immediate to deferred acceptance

Sunday, March 22, 2020

School choice without the assumption of full-information equilibrium by Kapor, Neilson and Zimmerman

And here's a post about a paper that takes outside options seriously from a different point of view.

Monday, December 14, 2020

Designing centralized marketplaces that work gracefully with pre-existing decentralized ones, in Management Science, by Benjamin Roth and Ran Shorrer

Signaling for Otolaryngology residency programs

 Here's a report on the use of signaling for residency positions, from the Oto match.

Pletcher, Steven, Chang, C.W., Thorne, Marc, MD, MPH & Malekzadeh, Sonya. (2022). The Otolaryngology Residency Program Preference Signaling Experience. Academic Medicine, 97, 664-668. https://doi.org/10.1097/ACM.0000000000004441

"The average applicant to Otolaryngology-Head and Neck Surgery in the 2021 residency application cycle applied to more than 50% of otolaryngology programs nationwide, submitting 77 applications, 1 a 34% increase over 5 years. 2 This surge has made it difficult for residency programs to holistically review applications and has limited opportunities for applicants to stand out to programs of particular interest.

...

"A formal preference signaling process provides all applicants with access to a known and stable quantity of signals. Through this process, at the time of application submission, students send a signal to indicate to a defined number of residency programs their particular interest in those programs. Such signals allow students to stand out to their favored programs and allow programs to receive a list of highly interested applicants. To our knowledge, this approach has not been used previously in the residency application process. Yet, articles advocating for signaling exist in the otolaryngology literature, 5-7 and the methodology, rationale, and results of preference signaling for graduates of economics PhD programs applying for faculty positions have been described. 8

"An OPDO working group, comprising the 4 authors, drove the establishment of a signaling process. In the spring of 2020, we held a series of meetings and webinars to engage stakeholders in the development and implementation of a signaling process. We included students, program directors, and specialty societies, such as the Society of University Otolaryngologists and the Association of Academic Departments of Otolaryngology Otolaryngology Chairs Organization. Additional discussions with the Association of American Medical Colleges, the Electronic Residency Application Service (ERAS), and the National Resident Matching Program also took place.

"In hindsight, establishing consensus across stakeholders proved to be the most challenging hurdle to successful implementation of our signaling process. Stakeholders had to accept this change and the inherent risks of implementing a "never before in medicine" process. These discussions, however, also provided a critical opportunity to refine our proposal and create an educational ecosystem that accepted this signaling process.

...

"All otolaryngology residency programs attested to the code of conduct, and none opted out of the signaling process. By October 21, 2020, the date that applications were released to programs, 611 students had submitted applications to otolaryngology residency programs, 559 applicants had submitted a Match list including an otolaryngology program, and 558 applicants had participated in the signaling process. Of 119 non-military otolaryngology residency programs, 118 received at least 1 signal. The number of signals received per program ranged from 0 to 71 with a mean of 22 (standard deviation 17) and a median of 16 

...

"Program directors most commonly reported using signals as a tiebreaker for similar applications and as part of an initial application review algorithm. One program required a signal to offer an applicant an interview.

...

"Applicants reported applying to a mean of 77 programs (standard deviation 21), including their 5 signaled programs. The rate of receiving an interview offer was significantly higher for signaled programs (58%, 670/1,150) compared with both nonsignaled programs (14%, 2,394/16,520; P < .001) and the comparative nonsignal program (23%, 53/230; P < .001; see Figure 2). To assess the impact of signaling across the spectrum of applicant competitiveness, we divided applicants into quartiles based on their overall likelihood of receiving an interview offer. Signals had a significant impact (P < .001) on interview offers across all quartiles (see Figure 3).

...

"The magnitude of signal impact we found likely represents both an increased rate of interview offers from signaled programs and a decreased rate of interview offers from nonsignaled programs. In contrast to our 5 signals, the American Economic Association provides 2 signals for graduates of economics PhD programs applying for faculty positions, suggesting that signal scarcity preserves its value and intent. 8 Decreasing the number of signals would force applicants to narrow their list of programs of primary interest and would disincentivize signaling "dream" programs. By increasing the number of signals, the lack of a signal becomes an indication of disinterest. If enough signals are provided, signaling could have a similar impact on the application process as an application cap. The ideal number of signals then must be explored.

"Our data demonstrated that signaling allowed applicants to influence their likelihood of receiving an interview offer from programs of particular interest. Given the distribution of signals received across programs, we believe that signaling also improved the distribution of interview offers among applicants, which could mitigate interview hoarding. 

...

"While applicants appear to benefit significantly from signaling, they also bear the responsibility of targeting their signals appropriately.

...

"Multiple specialties have expressed interest in adopting a similar program. However, otolaryngology is not representative of all medical or surgical specialties. It is a small, competitive surgical subspecialty with a 63% Match rate and no unmatched residency slots in the 2021 cycle. While the impact of signaling may vary significantly outside of these parameters, we are optimistic that the benefits will carry over to other specialties. Incorporating a signaling option within ERAS would facilitate both wide adoption and further analysis of such a process."

Streets of Gold, by Ran Abramitzky and Leah Boustan

 Ran Abramitzky writes:

As some of you know, I have a book coming out soon (with my long-time collaborator Leah Boustan) using big data to tell a new story about immigration and the American Dream. 

I’m thrilled to announce that Streets of Gold: America’s Untold Story of Immigrant Success will be published at the end of the month by PublicAffairs with preorders (hardcover and Kindle) available now. Audio book is also coming soon. 

 

 Leah and I felt compelled to write this book because we believe that immigration is one of the most fraught, and possibly most misunderstood, topics in American public life. Most of the things that we believe about immigration – both on the left and on the right – are based largely in myth, not in facts.

In setting out to establish the facts, we were like curious grandchildren searching for our own family tree, but a million times over. We analyzed millions of immigrant families in the past and today. What we found surprised us, overturning many of our own preconceptions. 

• Upward Mobility: Children of immigrants from nearly every country, especially those of poor immigrants, do better economically than children of U.S.-born residents – a pattern that has held for more than a century. 
• Rapid Assimilation: Immigrants accused of lack of assimilation (such as Mexicans today and the Irish in the past) actually assimilate fastest. 
• Improved Economy: Immigration changes the economy in unexpected positive ways. 

The book is a fast read, and we interweave the data with stories of immigrant families.  

I would truly appreciate your help leading up to the book’s launch. If you are interested in buying a copy, think about pre-ordering now. Preorders are essential for raising the visibility of new books. Please also share the word with other friends and family who are interested in America’s immigration history. 

 

Thank you! 

Ran

 

P.S. the book got some great endorsements (pasting here shortened versions):

“This wonderful and highly readable book sets the record straight about the hot-button issue of immigration. A must-read for anyone who care about this important issue.”

Daron Acemoglu, MIT, coauthor of Why Nations Fail

 

“A compelling story about how millions of immigrant families achieved the American Dream that will help reshape the narrative about immigration and opportunity in the United States.”

Raj Chetty, Harvard University

 

“Uplifting in its message, engaging in its composition, and powerful in its significance, Streets of Gold is A New World Symphony in words and numbers.”

Claudia Goldin, Harvard University

 

“Streets of Gold has the facts about the amazing and often surprising history of American immigration.” 

Angus Deaton, Nobel Laureate in economics

 

“A gem of a book, grounded in deep original research and made lively by moving personal accounts”

Esther Duflo, Nobel Laureate in economics

 

“A highly engaging book that separates fact and fiction and busts many of the myths that pervade the current discussion on immigration policy.”

Guido Imbens, Nobel Laureate in economics

 

“Unprecedented data, empathetic personal histories, joyous writing, practical solutions and a compelling counter-Zeitgeist narrative.”

David Laitin, Stanford University

 

“The optimism that runs through Streets of Gold is based on rock solid-evidence.”

Doug Massey, Princeton University

 

“Armed with reams of new data, elegantly written, and meticulously researched, Streets of Gold is as timely as it is magisterial.”

 Joel Mokyr, Northwestern University

 

“Fascinating and hard to put down history of American immigration, based on new sources of data, and conveyed by powerful story-telling”

Alvin E. Roth, Nobel laureate in economics

 

“Pathbreaking.”

Andrew Selee, President, Migration Policy Institute 

 

“An absolute treasure, the perfect book on immigration.”

Zack Weinersmith, New York Times Bestselling author of Soonish

 

Drought, hunger, and early marriage in Ethiopia

 Sometimes the problem is hunger, and early marriage is seen as the solution.

The Guardian has the story

Ethiopian drought leading to ‘dramatic’ increase in child marriage, Unicef warns. With hunger across Horn of Africa and 600,000 children out of school, ‘desperate’ parents push more girls into early marriage by Lizzy Davies

"Three consecutive failed rainy seasons have brought hunger, malnutrition and mass displacement to millions of people in the Horn of Africa, including parts of Ethiopia, Somalia, Kenya and Djibouti.

"Many girls in Ethiopia now face being married at a young age as their parents seek to find extra resources through dowries from the husband’s family, and hope their daughters will be fed and protected by wealthier families, warned Catherine Russell, Unicef’s executive director.

...

"In the East Hararghe zone, home to 2.7 million people, child marriage cases increased by 51%, from 70 recorded during a six-month period in 2020-21 to 106 in the same period a year later.

"It was just one of six drought-affected areas in Oromia to have seen a sharp rise in child marriages, Unicef said. Across those zones, cases have almost quadrupled. According to data received by Unicef this week, 672 cases of child marriage were recorded between February and August last year, whereas in the six months from last September to March this year, that number leapt to 2,282, local government figures showed.

"“We’re seeing increases in child marriage that are quite dramatic,” Russell said, noting that more than 600,000 children are thought to have dropped out of school as a result of the drought.

...

“These people [have their daughters married] because they’re desperate for one reason or another: they’re afraid of violence; they’re afraid for the safety of the girls; they need resources; they can’t afford to feed them,” Russell said.

...

"According to demographic data from 2016, 40% of girls in the east African country are married before the age of 18 and 14% are married before their 15th birthday.

...

"The drought is also pushing up the rates of severe acute malnutrition in the affected areas, with admission rates for children under five years old 15% higher in February this year than February last year."

Repugnant trade in (and study of) fossils

 Who should be allowed to export, study and display important fossils?

Nature has the story:

How a Brazilian dinosaur sparked a movement to decolonize fossil science. Rather than excitement, the discovery of the species set off a Latin American movement to stop colonial palaeontology.  by Mariana Lenharo & Meghie Rodrigues

"In December 2020, a paper in the journal Cretaceous Research sent shock waves through the palaeontology community1. It described a dinosaur species that the authors named Ubirajara jubatus — the first dinosaur found in the Southern Hemisphere to display what were probably precursors to modern feathers. The 110-million-year-old fossil had been collected in Brazil decades earlier — but no Brazilian palaeontologist had ever heard of it. The authors of the paper were from Germany, Mexico and the United Kingdom.

"It was the latest instance of what some researchers now call palaeontological colonialism, in which scientists from wealthy nations obtain specimens from low- and middle-income countries without involving local researchers, and then store the fossils abroad. The practice can sometimes be illegal. For instance, according to Brazilian law, the country’s fossils belong to the state, although the authors of the Ubirajara paper say that they had a permit signed by a Brazilian mining official allowing them to export the specimen.

...

"The practice can also deprive nations of knowledge and heritage, say researchers. “Fossils are special to us,” says Allysson Pinheiro, director of the Plácido Cidade Nuvens Palaeontological Museum in Santana do Cariri, Brazil, near where U. jubatus was found. “We have literature, arts and crafts, and music based on them.”

...

"Jeff Liston, president of the European Association of Vertebrate Palaeontologists, who is based in Edinburgh, UK, and has studied the illegal fossil trade in China, says that the scientific community has been aware of issues related to colonial palaeontology for some time — but the debate in the past few years has brought the discussion to a broader audience.

...

"In July, a panel will discuss scientific colonialism at the virtual Latin American Congress of Vertebrate Paleontology. The goal, according to Cisneros, is to promote true cooperation between palaeontologists. “We don’t want researchers from other countries to stop working here. What we hope for is that partnerships are more equitable and reciprocal. And that our laws are respected, as we respect the laws of other countries.”

...

"Minjin strongly advocates that fossils remain in their places of origin. “In Mongolia, fossils have been out of the country for the last 100 years,” she says. “Now we are facing an issue: how to find the next generation of scientists?” When children don’t grow up seeing fossils as part of their heritage and aren’t exposed to knowledge that excites them, she says, there is little motivation to become scientists."

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

I'm reminded of restrictions on the export of cultural treasures such as works of art. Here are some earlier posts...:

Wednesday, December 28, 2016

Repugnance watch: Wedgwood vase could be saved from export after culture minister intervenes

Saturday, September 19, 2009

Market for (smuggled) cultural treasures

The Development Innovation Lab at the University of Chicago, Led by Michael Kremer

 Here's the announcement from Chicago:

The Development Innovation Lab Launches at the University of Chicago, Led by Nobel Laureate Michael Kremer

The Becker Friedman Institute’s Development Economics Center is pleased to announce the launch of the Development Innovation Lab at UChicago. The launch will take place during Innovation and Development Week, to be held April 25-29 on the University of Chicago campus.

.

...

DIL’s team of professional researchers are actively engaged in cutting-edge research, including a new meta-analysis finding that water treatment reduces the odds of child mortality (death before age five) by about 30%. Drawing from this historic work, GiveWell recently announced its decision to recommend a grant of $64.7 million in new spending on water treatment, which could save thousands of lives.

“The University of Chicago’s commitment to development economics, through the launch of the Development Innovation Lab provides a tremendous opportunity to develop new knowledge on ways to address global poverty and ultimately to expand economic opportunity and improve lives,” said Kremer. “I look forward to helping build and grow the development economics community at UChicago and to advancing new research and experimentation to address a range of social and economic challenges.”

"Kremer was among the first economists to evaluate interventions in developing countries through randomized control trials. In 1998, he started a project on deworming in Kenya that has since improved the lives of millions of people. By randomizing treatments for intestinal worms at the school level, he and his collaborators found that their research initiative reduced student absenteeism by a quarter—and even carried positive outcomes to neighboring schools. Subsequent work also found that deworming had long-run impacts, leading to higher labor supply for men and more education for women.

"In addition to that research, Kremer helped develop the advance market commitment, proposing the idea of a contract that would guarantee a viable market for a costly product. Such commitments have stimulated private investment in vaccine research and the distribution of vaccines for diseases in the developing world."

The Future of Living Donor Kidney Transplants May 7, 2022 (online webinar hosted at U. Chicago)

Yesterday I posted about the increasing incidence and prevalence of end stage renal disease. 

On Saturday I'll be taking part in a medical education webinar, open to the general public, on avenues to increase the availability of safe, ethical and legal kidney transplants.  Some will find it controversial*, even repugnant, since one of the big topics is the ethics of compensating kidney donors. (I'll be talking about some  of the incremental improvements that have been and can be pursued while that discussion goes on. Some of those have also had to overcome some opposition...)

There's an all-star cast of speakers.

The Future of Living Donor Kidney Transplants

May 7, 2022; Virtual; Admission Is Free (join at the link above)

7AM-10 AM (PDT); 9AM-12Noon (CDT); 10AM-1PM (EDT)

Session 1: Ethics of Gifting or Compensation of Donors
Topic	Presenter (s)	Comments	Time (mins.)
			Item	Cu mul.
Ethics of Compensating (“Rewarding”) Donors	Janet Radcliffe Richards	World renown philosopher/ethicist. (Oxford). Book: the ethics of transplants why careless thought costs lives	30	30
Questions, Comments, and Recap Session 1	CON: Asif Sharfuddin M.D. FASN FAST PRO: Sally Satel M.D. M.S.		30	60
Session 2: Living Donor Transplant Issues
Cost-Benefit Analysis of Compensating (“Rewarding” Kidney Donors	Frank McCormick Ph.D.	How the Government Can End the Kidney Shortage and Save More than 40,000 Kidney Failure Patients Each Year by Compensating Living Kidney Donors. Total economic value to kidney recipients is $76B/yr. Net savings to the taxpayers is $7B/yr.	15	75
Current Status and Future Developments in Kidney Exchange Programs	Alvin Roth, Ph.D. Nobel Laurette	Living donor organs are being increasingly allocated by paired and exchange organ programs; This is the only major technical improvement in transplantation in years;	15	90

Session 2: Living Donor Transplant Issues Cont’d
Decreasing Barriers and Increasing Access for Living Donation	Cody Maynard; Independent Living Donor Advocate (NKDO)	Immediate actions we can take to increase the pool of living donors.	10	100
Discussion and Recap of Session 2 (John Fung, M.D, Ph.D.)			10	110
Break			10	120
Session 3: More Living Donor Transplant Issues
Experiences of a Living Kidney Donor;	Martha Gershun, MBA	Author of a recent book with J.D. Lantos MD: Kidney to Share.	10	130
U.S. Public Attitudes Towards Compensating Donors	Thomas Peters M.D.	Two peer reviewed studies show that 70% of US population support compensating donors $50K.	10	140
Risk and Safeguards for Living Donors	Arthur Matas, M.D., Ph.D.	Screening donors is essential. Risks are small but not zero.	15	155
The Limits of Increased Counts of Deceased Donor Transplants	John P. Roberts M.D.	Ignorance is common: Increasing the Deceased Donor pool is constrained by the limits of brain- dead donors; <2% of U.S. deaths.	10	165
WaitList Zero’s role in Living Donation	Josh Morrison J.D.; Founder of WaitList Zero	“Thanks for helping us, we were lost!” comment by a recipient, pointing to the need for education regarding living donors.	10	175
Discussion and Recap Session 3 (Thomas Peters M.D.)			10	185
Recap and Summary of the Symposium Glenn Chertow M.D., MPH			20	205

* Part of the controversy is that some advertisements for the webinar were deleted, here are some tweets on the subject:

End-stage Kidney Disease in the U.S. has doubled since 2000

 Kidney disease is on the rise in the U.S. Transplantation is the treatment of choice, but doesn't begin to meet the need.

JAMA has the story:

End-stage Kidney Disease Doubles  by Bridget M. Kuehn, MSJ, JAMA. 2022;327(16):1540. doi:10.1001/jama.2022.5342

"The number of people living with end-stage kidney disease (ESKD) more than doubled between 2000 and 2019—from 358 247 to 783 594—according to an analysis of data from the United States Renal Data System (USRDS). A 41.8% increase in new cases also occurred during the study period, from 92 660 cases to 131 422 cases. Hypertension and diabetes were driving factors.

"Substantial racial and ethnic disparities in ESKD rates remain a concern. Among Asian people, new ESKD cases increased from 2507 cases in 2000 to 6256 cases in 2019—a 149.5% increase that was the largest in any racial or ethnic group. During the study period, new cases increased from 25 917 to 33 700 among Black people, from 11 297 to 20 790 among Hispanic people, from 742 to 1458 among Native Hawaiian or other Pacific Islander people, and from 51 156 to 67 919 among White people.

...

"They note that in 2019 alone, Medicare spent $37.3 billion or 7% of all claims on ESKD, according to USRDS data."

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

Update: Here's the USRDS 2021 Annual Data Report, and 

here's End Stage Renal Disease: Chapter 1: Incidence, Prevalence, Patient Characteristics, and Treatment Modalities

Highlights:

• In 2019, 134,608 individuals were newly diagnosed with end-stage renal disease (ESRD), representing an increase of 2.7% from the previous year and 15.8% from a decade ago (Figure 1.1). However, the adjusted incidence fell from a peak of 431 per million population (pmp) in 2006 to 386 pmp in 2019.
• In 2019, 85% of those with incident ESRD initiated in-center hemodialysis (HD) (Figure 1.2). This represents a decrease from 91% in 2009. Over the past decade, the percentage initiating kidney replacement therapy with peritoneal dialysis (PD) nearly doubled, from 6% to 11%. The percentage who received a preemptive kidney transplant remained unchanged over the decade at about 3%.
• Adjusted ESRD incidence increased as age increased: among individuals aged 0-17 years, the adjusted incidence in 2019 was 12 pmp; among individuals aged 65-74 years, 1,307 pmp; and among individuals aged ≥75 years 1,587 pmp (Figure 1.4).
• Between 2009 and 2019, adjusted ESRD incidence in Black individuals decreased by 17.5%, in Native American individuals by 14.1%, in Hispanic individuals by 12.1%, in Asian individuals by 5.2%, and in White individuals by 2.4% (Figure 1.4). However, in all individuals except for Whites, adjusted incidence increased between 2018 and 2019.
• The prevalent count of individuals with ESRD reached 809,103 in 2019, an increase of 41.0% from 2009 (Figure 1.5). Adjusted ESRD prevalence also increased to an all-time high of 2302 cases pmp in 2019. 
• At the end of 2019, 492,096 individuals were receiving in-center HD, up 1.7% from 2018 and 34.5% from 2009 (Figure 1.6). There were 12,243 patients performing home HD at year’s end, an increase of 20.1% over the preceding year. The number of individuals receiving PD increased to 62,275, representing 8.5% growth in a single year.
• Adjusted ESRD prevalence in Black individuals was far higher, at 6423 pmp, than in other racial and ethnic groups; adjusted prevalence in Black individuals was 78.6% higher than in the next-highest group, Native Americans, and more than fourfold higher than in White individuals (Figure 1.8).
• The percentage of patients with prevalent ESRD who had a functioning kidney transplant was highest among White (36%) and lowest among Native Hawaiian and Pacific Islander (18%) individuals. Conversely, White individuals had the lowest percentage receiving in-center HD (54%), and Native Hawaiian and Pacific Islander individuals had the highest (73%) (Figure 1.10).
• White (73%), Asian (72%), and Native American (72%) individuals were much more likely to have received pre-ESRD care compared with Black (64%), Native Hawaiian/Pacific Islander (62%), and Hispanic (61%) individuals (Figure 1.11). 
• In 2019, 39% of patients had an estimated glomerular filtration rate (eGFR) ≥10 mL/min/1.73 m² at ESRD onset (Figure 1.14). The mean eGFR at initiation of kidney replacement therapy was 9.6 mL/min/1.73m2 (Table 1.3). Overall, 60.6% of incident patients with ESRD had diabetes mellitus (DM), 28.4% heart failure (HF), and 20.8% other cardiac disease (Figure 1.18). Fully 77.5% of Native American individuals had DM, compared with 57.8% of White individuals.
• Cardiovascular disease (CVD) was present in 77.3% of patients receiving HD, 66.4% of patients receiving PD, and 54.8% of patients with a kidney transplant.

The search for tennis talent is unraveling

 It used to be that 11 year old professional tennis players were rare, but it looks like that's not the case any more. The NYT has the story:

Are the Next Global Tennis Stars Among These Tweens? The search for elite players is so competitive that IMG, the agency that once ruled tennis, is cultivating preteens to find the next prodigy  By Matthew Futterman

"The race to find the sport’s next stars has come to this: With eight-figure fortunes potentially at stake, agents and scouts are evaluating and cultivating players even younger than 10 who are just getting started in serious competition.

...

“Nobody wants to have a tournament for 11- and 12-year-olds,” said Max Eisenbud, who leads the company’s tennis division. “I’d rather wait, but the competition forced us into this situation.”

"For years, IMG’s agents collected future stars in two ways: Tweens and young teens (Maria Sharapova for example) either showed up at its academy in Bradenton, Fla., once the premier training ground in the sport, looking for one of the plentiful scholarships; or the agents showed up in Tarbes, France, for Les Petit As, the world’s premier tournament for players younger than 14. 

...

"in recent years, when Eisenbud and his colleagues made their annual trips to Les Petit As, they found that nearly all the most promising players had already signed contracts with other management companies, many of them well-funded boutique operations that were offering generous financial guarantees, sometimes stretching well beyond covering the roughly $50,000 annual cost for coaching and travel on the junior circuit.

"And so, in a sign of cutthroat times in tennis, IMG is aiming younger, even if prospecting preteen talent can be nearly impossible and highly fraught, risking increasing the pressure on children who already put plenty on themselves and, in some cases, carry the financial responsibilities for their struggling families.

...

"Eisenbud famously signed Sharapova when she was 11 years old after watching her hit for 45 minutes with an intensity and flawlessness he had never before seen. Carlos Alcaraz, who turns 19 on Thursday and is already the hottest young player in the men’s game, was deemed worthy of investment as a can’t-miss 11-year-old, too. Then again, Eisenbud was sure the first player he signed, Horia Tecau of Romania, was destined for greatness. Tecau became a top doubles specialist but never cracked the top 300 in singles.

...

 "Finding a future top 50 player from a country or a demographic group that has never produced a tennis star could be groundbreaking and incredibly lucrative."