Deceased donor organ discards on weekends, in the the Annals of Transplantation

 Hospital resources and physician incentives can be stressed on weekends, and there is historical evidence that organ discards are higher on weekends.  Here's a study suggesting that is still a thing.

Yamamoto, T., A. Shah, M. Fruscione, S. Kimura, N. Elias, H. Yeh, T. Kawai, and J. F. Markmann.  Revisiting the "Weekend Effect" on Adult and Pediatric Liver and Kidney Offer Acceptance. Annals of Transplantation. 2022 Nov;27:e937825. DOI: 10.12659/aot.937825. PMID: 36329622.

"BACKGROUND: Weekends can impose resource and manpower constraints on hospitals. Studies using data from prior allocation schemas showed increased adult organ discards on weekends. We examined the impact of day of the week on adult and pediatric organ acceptance using contemporary data.

"MATERIAL AND METHODS: Retrospective analysis of UNOS-PTR match-run data of all offers for potential kidney and liver transplant from 1/1/2016 to 7/1/2021 were examined to study the rate at which initial offers were declined depending on day of the week. Risk factors for decline were also evaluated.

"RESULTS: Of the total initial adult/pediatric liver and kidney offers, the fewest offers occurred on Mondays and Sundays. The decline rate for adult/pediatric kidneys was highest on Saturdays and lowest on Tuesdays. The decline rate for adult livers was highest on Saturday and lowest on Wednesday. In contrast, the decline rate for pediatric livers was highest on Tuesdays and lowest on Wednesdays. Independent risk factors from multivariate analysis of the adult/pediatric kidney and liver decline rate were analyzed. The weekend offer remains an independent risk factor for adult kidney and liver offer declines, but for pediatric offers, these were not significant independent risk factors.

"CONCLUSIONS: Although allocation systems have changed, and the availability of kidneys and livers have increased in the USA over the past 5 years, the weekend effect remains significant for adult liver and kidney offers for declines. Interestingly, the weekend effect was not seen for pediatric liver and kidney offers.

The past and future of the transition from medical school to residency, in the Journal of Graduate Medical Education, by Williamson, Soane, and Carmody

 The October issue of the Journal of Graduate Medical Education considers the past and future of the transition to residency.

The US Residency Match at 70: What Was, What Is, and What Could Be  by Edwin Williamson, MD; Caroline Soane, BA; J. Bryan Carmody, MD, MPH, J Grad Med Educ (2022) 14 (5): 519–521., https://doi.org/10.4300/JGME-D-22-00248.1

"But while early offers are long gone, the residency selection process now faces a new set of challenges related to the increasing number of applications submitted by contemporary applicants. In 2020 the average US medical school graduate submitted 70 residency applications.9  The average for some specialties is even higher. For instance, in 2022, the average osteopathic medical school applicant in obstetrics and gynecology submitted 85 applications, while US MD applicants in orthopedic surgery submitted 96 applications, and international medical graduates submitted 100 applications each to internal medicine programs.10  This overapplication increases costs for applicants and programs, leads to reliance on convenient screening metrics in applicant evaluation, and does not ultimately improve Match rates.9 "

The UpFront market for television ads: is it time to change its timing?

The coronavirus pandemic is an opportunity for advertisers and television networks to renegotiate an odd feature of their market for advertisements.  As I understand it, advertisers wishing to purchase blocks of advertising for Fall television series have to do so early, in the Spring, in what is called the upfront market.  This runs so early that some of the shows are still in the early planning stage, so that advertisers have some descriptions of plot lines and target demographics, but they are buying ads in shows that no one has seen yet.

The WSJ has the story:

Big Advertisers Call for a Seasonal Time-Shift in TV’s Upfront Marketplace
Procter & Gamble, Bank of America and others want to move upfront negotiations for ads in the multibillion TV market to the fall from the spring.  By Sahil Patel

"Big-brand advertisers and an industry trade group are calling on the television networks to delay their annual upfront ad marketplace to later in the year—a big shift in the way TV programmers and advertisers have done business for decades.

"The push is driven in part by the havoc the coronavirus has caused in the television business, from the shutdown of production to the big question mark over when sports will return. Both are critical to advertisers: they say there is a lack of visibility into what they would be buying. Ad budgets also are in flux as many advertisers have pared spending during the recent downturn. Many are struggling to figure out what next year’s budgets will look like.
...
"The TV industry has operated on a broadcasting and advertising calendar that starts in September since 1962, when ABC decided to debut all its programs after Labor Day. Normally, TV networks pitch their new programming at glitzy New York City events in the spring and negotiate ad deals for the fall season soon after.

This year, however, the live upfront events were canceled due to the virus, and executives now expect deal-making will drag out through the year.
...
"The trade group said there is still value in negotiating ad deals upfront—they would just prefer to shift the timeframe. Upfront deals are beneficial to advertisers as they are able to get lower prices, especially with a limited supply of inventory, and maintain protections like make-goods—which aren’t available to advertisers buying in the “scatter” market, when ads are purchased closer to the time they air."

Why is it hard for securities exchanges to restore price competition (instead of speed competition)?

Many stock exchanges earn rents by giving privileged access to high speed algorithmic traders.  Why doesn't a new exchange enter the market with a design that would privilege price competition over speed competition?  Budish, Lee and Shim have some thoughts on that:

Will the Market Fix the Market?A Theory of Stock Exchange Competition and Innovation
 Eric Budish, Robin S. Lee and John J. Shim
February 27, 2019

Abstract As of early 2019, there are 13 stock exchanges in the U.S., across which over 1 trillion shares ($50 trillion) are traded annually. All 13 exchanges use the continuous limit order book market design, a design that gives rise to latency arbitrage—arbitrage rents from symmetrically observed public information—and the associated high-frequency trading arms race (Budish, Cramton and Shim, 2015). Will the market adopt new market designs that address the negative aspects of high-frequency trading? This paper builds a theoretical model of stock exchange competition to answer this question. Our model, shaped by institutional details of the U.S. equities market, shows that under the status quo market design: (i) trading behavior across the many distinct exchanges is as if there is just a single “synthesized” exchange; (ii) competition among exchanges is fierce on the dimension of traditional trading fees; but (iii) exchanges capture and maintain significant economic rents from the sale of speed technology—arms for the arms race. Using a variety of data, we document seven stylized empirical facts that align with these predictions. We then use the model to examine the private and social incentives for market design innovation. We show that the market design adoption game among exchanges is a repeated prisoner’s dilemma. If an exchange adopts a new market design that eliminates latency arbitrage, it would win share and earn economic rents; perhaps surprisingly, the usual coordination problems associated with getting a new market design off the ground are not central. However, imitation by other exchanges would result in an equilibrium that resembles the status quo with competitive trading fees, but now without the rents from the speed race. We conclude that although the social returns to adoption are large, the private returns are much smaller for an entrant exchange and negative for an incumbent that currently derives rents from the inefficiencies that the new design eliminates. Nevertheless, our analysis does not imply that a market-wide market design mandate is necessary. Rather, it points to a more circumscribed policy response that would tip the balance of incentives and encourage the “market to fix the market.” 

College Admissions as Non-Price Competition: The Case of South Korea

Chris Avery and Soo Lee and I have a new NBER working paper:

College Admissions as Non-Price Competition: The Case of South Korea

Christopher Avery, Alvin E. Roth, Soohyung Lee

NBER Working Paper No. 20774
Issued in December 2014
NBER Program(s):   ED 

This paper examines non-price competition among colleges to attract highly qualified students, exploiting the South Korean setting where the national government sets rules governing applications. We identify some basic facts about the behavior of colleges before and after a 1994 policy change that changed the timing of the national college entrance exam and introduced early admissions, and propose a game-theoretic model that matches those facts. When applications reveal information about students that is of common interest to all colleges, lower-ranked colleges can gain in competition with higher-ranked colleges by limiting the number of possible applications.

This paper is available as PDF (474 K) or via email.

A data appendix is available at http://www.nber.org/data-appendix/w20774 

Budish, Cramton and Shim on The High-Frequency Trading Arms Race

Presently most stock markets, such as the New York Stock Exchange, and most futures markets, such as the Chicago Mercantile Exchange, use a market design called the continuous limit order book."Continuous" means that whoever accepts a bid or ask first gets the trade. This can create a race that doesn’t have an economic purpose. (Billions have been spent on optical fiber cables and microwave channels to shave milliseconds off how quickly traders can compare prices in NY and Chicago.) It can also make the market thinner in costly ways. (Liquidity providers have to quote wider bid-ask spreads to protect themselves against getting ‘sniped’ if there is a news event and they don’t adjust their quotes fast enough.)

An exciting market design paper documents this and suggests a solution (run a batch market every second, so that traders would have to compete on price rather than time):
The High-Frequency Trading Arms Race: Frequent Batch Auctions as a Market Design Response
by Eric Budish, Peter Cramton, and John Shim

Abstract: We propose frequent batch auctions – uniform-price double auctions conducted at frequent but discrete time intervals, e.g., every 1 second – as a market design response to the high-frequency trading arms race. Our argument has four parts. First, we use millisecond-level direct-feed data from exchanges to show that, under the continuous limit order book market design that is currently predominant, market correlations that function properly at human-scale time horizons completely break down at high frequency time horizons. Second, we show that this correlation breakdown creates purely technical arbitrage opportunities, which in turn creates an arms race to exploit such opportunities. Third, we develop a simple theory model motivated by these empirical facts. The model shows that the arms race is not only per se wasteful, but also leads to wider spreads and thinner markets for fundamental investors. Last, we use the model to show that batching eliminates the arms race, both because it reduces the value of tiny speed advantages and because it transforms competition on speed into competition on price. Consequently, frequent batch auctions lead to narrower spreads, deeper markets, and increased social welfare.
*************
Figure 1.1 of the paper beautifully illustrates why speed pays: it only takes milliseconds for a price movement on index futures in Chicago to be matched by a corresponding price change on the exchange-traded index fund in NY. Whoever sees that discrepancy first can earn the full arbitrage profits. (In a batch market every second, traders would have to compete for these...)

Tim Harford has a nice summary of the paper here.
***************

The NY Times covered a different kind of early information (seconds not milliseconds, involving survey results, not prices) in this pair of before and after stories: Thomson Reuters to Suspend Early Peeks at Key Index, Fair Play Measured in Slivers of a Second

From the second story:
"On Friday morning, Thomson Reuters released the latest University of Michigan Consumer Sentiment Index, as it does twice a month. But this time was different. As a result of a settlement Thomson Reuters reached this week with New York’s attorney general, Eric T. Schneiderman, a select group of its customers didn’t get the two-second advance release they’d been buying.
...
"The difference was arresting. On Friday, just 500 shares of a leading Standard & Poor’s 500 exchange-traded fund traded during the first 10 milliseconds of the two-second window before the release of the University of Michigan data to Thomson Reuters’ regular clients, according to the market research firm Nanex. A year ago, on July 13, 2012, 200,000 shares traded during that 10-millisecond period, Nanex said."
*******************

I shared a draft of this post with Eric Budish, who replied as follows:

"If you wanted to hook this paper into your own work, here are some potential connections (we chatted about these connections last time I was in Stanford):
- Serial vs. batch processing: we are criticizing continuous limit order books, which process messages one-at-a-time in serial and hence induce speed races, and proposing a batch auction in its place. This reminds me of your 1997 JPE paper on serial vs. batch processing …
- Congestion: the speed race creates congestion for the exchange’s computers, which leads to a backlog in processing messages, which leads to traders being confused about the state of their orders, which creates uncertainty and occasionally bigger problems (backlog is most severe at times of especially high market activity, when reliance on low-latency information is also at its highest). We talk about this a bit in Section 8 of the paper
- Sniping: our empirical work and theory model highlight that an important cost of liquidity provision under the continuous limit order book is that liquidity providers are constantly getting “sniped” – when there is an arbitrage opportunity, such as the one you can see in Figure 1.1 of the paper, some poor liquidity provider is on the other side of that arbitrage opportunity and is losing money … he ultimately passes this cost on to fundamental investors via a wider bid-ask spread
- Thickness: continuous time is the ultimate thin market, in most dt’s there is no activity whatsoever …

Not sure that any of this is worth mentioning, but it’s fun to see all of these themes from your work coming up in so different a context."

Timing of theater reviews

I have a longstanding interest in the timing of transactions (such as unraveling, when transactions become early, or sniping, when they become late, or congestion, when they take a long time, or deadlines). So I read with interest Catherine Rampell's piece on Theater Review Economics, about the timing of theater reviews. (Apparently she's a theater reviewer as well as an economics correspondent.  I guess I won't tell you what I do when not reviewing economics...)

It turns out that when she interviews show producers, one of the answers she gets concerns unraveling (although she discounts this possibility...).


"...as some of you may know, we have an odd little tradition in theater criticism, in that we (almost) never publish a review until after a production’s official opening night. I’ve long wondered about whether it makes good business sense for productions to enforce this embargo.

"While reviews run after opening night, they’re rarely based on a viewing of the actual opening night performance; the curtain generally falls much too late for critics to meet their deadlines for the next day’s paper. Instead, critics usually are invited to attend one of the preview performances after the show has already been “set” or “frozen” — that is, after the director and rest of the creative team have decided not to make any more major changes.

"The time between freezing and opening varies, but it’s generally somewhere from a couple of days to a week.

"I’ve been especially curious about review embargoes lately because summer theater productions usually have very short runs, and should theoretically want reviews published as early as possible — well before the show closes, anyway. Most of the shows I review during the rest of the year have pretty short runs, too, including some productions that last less than two weeks.

"I understand the desire to turn opening night into a big event to magnify press attention, as is done with the openings of big, star-studded movies and their sumptuous red carpets.

"But for a vast majority of theatrical events, little attention is paid to the opening-night parties and such. Even when publications do run photos of the pomp and circumstance of a play’s opening night — if Scarlett Johansson is starring in the show, say — that coverage usually appears in news articles and Us Weekly spreads, not critical reviews.

"Eager for the perspective of those who have money on the line, I called two longtime producers for their thoughts.

"The first was Roger Berlind, a phenomenally successful theater producer who has won 18 Tonys and mounted 80 Broadway shows since 1976, four of which are still running. (Another, “Annie,” opens in November.)

"He noted that when he began producing shows, critics attended on opening night and wrote a review for the late edition of the next day’s paper, since deadlines were often later then. He didn’t sound all too thrilled that the policy had changed.

"Today, he said, producers and press reps encourage the big critics to come a day or two before opening night, even though attending earlier is an option, because the show continues to improve up through the opening night even after the show is set. He said he worried that if critics were able to publish as soon as they saw the show, more of them would rush to see the production as early as possible because “critics are extremely competitive.” That rush would place pressure on the cast and creative team to polish the performances earlier. “Then you’d have to back up the entire process starting with the first day of rehearsal, and I don’t think that would be productive,” he said. “It’s expensive to go through the rehearsal process already.”
**************


I wonder whether the embargo on theater reviews might serve some of the same function that embargoes on news releases do...

Is the market for professors of English becoming less thick?

That's the question raised by a recent article on the job market organized by the Modern Language Association: Realities of the Endless Search

 "The MLA meeting (until recently in late December and now in early January) has for decades been the primary place where search committees in English and foreign languages interviewed a large number of candidates and then selected a small group for campus visits. So the fall was the time for the initial vetting of the large pool to determine who was worthy of an MLA interview. Now, the schedule is much less firm. Susan Miller, English chair at Santa Fe College, a Florida community college, said that she has had searches in which money wasn’t available on the regular schedule, but then materialized late in the year. So the college advertised a job last March, "a really awkward time for a fall opening." But she said that the department didn’t want to lose its shot at the position, so it went ahead as soon as it could -- and in fact rushed the process, feeling that until someone had signed a contract, the position might disappear."

The true meaning of "fashion forward." Coordinating dates in NY, London, Paris, and Milan

The fashion forward among you will probably be as relieved as I am to know that New York Fashion Week Finally Has An Official Start Date: September 6th

The back story comes to me via Assaf Romm and Dvorah Marciano. They write as follows.

"So Fashion Week is a concept invented in NYC around 1943 (back then it was called "Press Week") when there was not enough French fashion coming from across the ocean due to the German occupation. Around 1993 it took its current form in which there are a lot of fashion people and media coming to one place to plan their Fall/Spring buys and so on. Furthermore, the Fashion Week was copied by many other cities. Specifically, the main events are the Fashion Weeks in NYC, London, Paris and Milan. These events take place consecutively twice a year (around February for the Fall collection, and around September for the Spring collection of next year): 

http://www.slate.com/articles/arts/fashion/2006/02/how_the_runway_took_off.html

"It should be mentioned that these Fashion Weeks compete on fashion buyers, media coverage and even models. For example:

http://www.huffingtonpost.com/2011/09/20/london-fashion-week-losing-models-milan-_n_971347.html

"Apparently, scheduling the Fashion Weeks between the big four cities is an ongoing saga, with dates moving earlier and earlier (...I don't have specific data yet). That's why they signed a three-year agreement in 2008 to determine schedules. Obviously, recently there were some issues with Milan moving its dates to coincide with the NYC and London weeks in September 2012. And it seems like Paris also joined in to the fight:

http://fashionablyjust.com/2011/12/fashion-week-wars-volume-xxxxiiiiii/

"Finally, it looks like today a final agreement has been reached: [see top of post]. 

"To conclude, this looks like a great unraveling story, because you obviously cannot move Fashion Weeks too early (well, according to Dvorah, you just cannot introduce new fashion too early, or otherwise it wouldn't be fashionable by the time it reaches the consumers....). Also, it seems like fashion highly depends on information. That is, fashion is a form of art, and it is determined by current events ..."

And here's the International Fashion Week Dates Agreement of 2008

Uniform notification date for postdoctoral positions in professional psychology

APPIC, the Association of Psychology Postdoctoral and Internship Centers, runs a centralized match for (pre-doctoral) internships that uses the Roth-Peranson algorithm, which replaced the prior telephone market, which suffered from congestion.
As their name suggests, they also are involved with postdoctoral positions. The field of clinical neuropsychology also operates a postdoctoral match, but the other postdoctoral areas do not. Recently APPIC has taken steps to try to organize that market in a decentralized way.

In May of 2011 APPIC polled its member postdoctoral programs about whether they would prefer a system that operated with a uniform offer notification date versus a uniform acceptance date. Under a uniform acceptance date, programs could make offers whenever they liked, but all offers would be supposed to remain open until the designated acceptance date. Under the uniform notification date, all offers would be made at the same time, with applicants having a short time to reply.

My understanding is that the organization has decided to go ahead with a uniform notification date, which would however allow programs to make early offers if one of their non-complying competitors makes an early exploding offer to a candidate to whom they are planning to make an offer themselves. Here's an outline of the proposed rules. I worry that some of the same problems that afflicted the old telephone market for internships may quickly resurface...(and that this proposed organization of the market will not work as well as the reorganization of the market for gastroenterologists, which instead of dealing with reciprocal offers by employers, empowered applicants to change their minds on early acceptances...)

Uniform Notification Date with Option for Reciprocal Offer (UNDr)

March 14, 2012

UNDr Procedure

All APPIC non-neuropsychology postdoctoral programs (those that do not offer the specialty of clinical neuropsychology) will make offers to applicants only on the APPIC selected date for offers. Programs may make an exception if an applicant is made another earlier bone fide offer, which must follow the guidelines below. On March 14, 2012,  at Noon EST, the program will call their top candidate. Once an offer is made to an applicant, the applicant may proceed with one of the following actions: accept the offer, decline the offer, or hold the offer for four hours. If the position is held, it is considered to be frozen and cannot be offered to any other candidate during that time period. (At the four hour mark, the candidate must either accept or decline, otherwise the offer is no longer valid). Candidates may not hold more than one offer at a time. Once a candidate accepts an offer they should call the remaining programs that are lower on their  preference list and inform them that they no longer wish to be considered at those facilities. Postdoctoral Training Directors (or their designee) will contact all applicants by phone or e-mail on the day of the UND to inform them of the status of the position. After a site and an applicant come to an agreement, a formal offer letter will be mailed to the applicant who will then formally accept the offer in writing.

Reciprocal Offers Process
Candidates who have been made an offer from a non-APPIC site (whether clinical or research postdoc or job offer) requiring a decision prior to UND date may contact an APPIC site request a reciprocal offer. The candidate would indicate the name of the program making the competing offer and how long they have been allowed to hold their offer. Before making a reciprocal offer to the candidate, the APPIC site should call the candidate's Internship Training Director and verify the offer or ask the applicant for written verification of the competing offer (e.g., a faxed or scanned letter or a forwarded e-mail).

When an APPIC program makes a reciprocal offer, the candidate is expected to accept immediately. The acceptance is binding. If a program declines to make a reciprocal offer, only then is the candidate permitted to contact another site indicating it is (now) their #1 choice.

Application Deadlines
Application deadlines are permitted at any point prior to UND as determined by each program.

Notification of Applicants Who are No Longer Being Considered
APPIC programs should notify applicants at the point that they are out of consideration for the position for which they have applied.

UNDr Posting by APPIC Postdoctoral Members
By September 24, 2011, APPIC postdoctoral programs are expected to update their brochures, website, and directory information to explain their use of the UNDr process.

Programs who Wish to Make Offers after UND
Programs are permitted to make offers after UND if they are uncertain of funding at time of UND.

Clearinghouse
No clearinghouse will be set up during this initial year. Programs that do not fill positions on UND may fill their empty positions on any future date.
 

UNDr Frequently Asked Questions

Does the UNDr process apply to non-APPIC postdoctoral programs?
APPIC is currently marketing this process to non-APPIC postdoctoral programs as a mechanism of providing increased collaboration among all training programs. Many non-APPIC postdoctoral programs previously participated in an informal UND process. These programs in particular have all been contacted personally to request their continued participation as in years past. Any program who would like to participate is most welcome to do so and we strongly encourage every program to follow this procedure. We ask any non-APPIC program who wishes to participate to contact Dr. Lisa Kearney at Lisa.Kearney3@va.gov so that they can be kept informed of any updated processes as they occur.

Does APPIC plan to move forward to a formal match system for postdoctoral programs as it previously did with the internship?
There is no current plan to move forward to a formal match system. However, the APPIC Board will continue to survey members regarding their interest and commitment to a formal match system, and implement as voted on by the membership.

If I do not obtain funding for a new postdoctoral position until AFTER the UNDr date, may I proceed with filling the position after the UNDr date?
Yes! If you receive funding after the UNDr date, you may proceed with recruitment for the fall. This is also the same for new internship programs who receive funding after the Match date.

I have a Neuropsychology Postdoctoral program which does not participate in the formal neuropsychology match system. Must I participate in the UNDr process?
No, Neuropsychology Postdoctoral programs are not included in this process as they already have a process for organizing offers available to them through the APPCN match system.
 

Regulating fast trading on Wall St

David Silver has a nice article in the NYT comparing the proposed regulation of "flash trading" with some of the century old regulation of floor trades (and of "front running" before customer orders generally): A Short History of Fast Times on Wall Street . ("Flash trading":= Some exchanges have, for a fee, given some traders "pre-routing display" of bids and asks milli-seconds before they are shown to most traders. See Direct Edge.)

"Supercomputers allow certain traders to profit by executing trades in milliseconds, a practice known as high-frequency trading. These traders also use a technique called flash orders that gives them a sneak peek at other investors’ orders to buy and sell stock. ...

"...similar criticisms have been made for over 100 years, since the days when trades on the New York Stock Exchange were executed by humans using notepads and pencils.
Even back then, critics claimed that the exchange members who were physically present on the floor could get trading information and execute their own orders faster than anyone else. The creation of the Securities and Exchange Commission in 1934 included the power to regulate the buying and selling of securities by exchange members trading for themselves, rather than for customers.
A Roosevelt administration official testifying in support of the 1934 legislation, Thomas Corcoran, described such floor traders as “chiselers.” This referred to their ability to quickly buy from sellers at prices lower than they would otherwise get, and promptly resell to buyers at prices higher than they would otherwise pay.
These complaints were well founded. By being on the exchange floor, traders could see with their own eyes the prices of completed trades minutes before they appeared on the exchange tape. Executing their own orders gave them a head start over ordinary investors, whose orders could take minutes to reach the floor. As a former Wall Street Journal editor wrote in 1903, “They know the prices even before they are recorded on the tape, and they are able to join in every upward movement the moment it begins, and to abandon it the moment it shows signs of wavering.”
In 1909, a committee created by Gov. Charles Evans Hughes of New York to study stock market abuses similarly commented that floor traders “acquire early information concerning the changes which affect the values of securities,” giving them “special advantages” over other traders. "

Delaying kindergarten entry

The Telegraph discusses the problem of "summer born children," who would be younger than their kindergarten peers if enrolled according to the usual school schedule: Does it pay to delay the start of your child's schooling?. The article focuses on the American experience:

"A survey by the US Department of Education in 2007 found that 14 per cent of children aged 5 to 6 had delayed entry into school, or had parents who planned to delay their entry. In some areas - most often those where parents can afford an extra year of pricey pre-school - the level can reach as high as 25 per cent of the classroom.
The practice is more common among boys and tends to be concentrated in some geographic areas, though nearly absent in others. “Middle-class parents are savvy about wanting to know what the trends are and wanting to make sure that their kids aren't outside the norm,” says one education professor.
That's what comes across in a recent post on a parenting blog from an anxious mother in New Jersey. “I am thinking of holding my daughter back so she is emotionally ready for kindergarten,” she wrote, “but I'm also thinking about it because I worry that she will be the youngest since everyone else is holding back.”
“It's pernicious,” says Morrison, who is concerned, as are many other educators, about the effects on the rest of the student body.
Already, teachers must reckon with children who are 12 months apart in age - a big difference when they are just 5 years old. “On every dimension you can think of, you are going to have kids stretched out along a continuum,” says Beth Graue, a former kindergarten teacher, who studies school readiness at the University of Wisconsin. “You've got to accept that you are going to have gigantic five-year-old girls and tiny five-year-old boys who are going to want to do different things.” When some children begin school a year later than their peers, the range - and the challenge for the teacher - is that much bigger."

If schools are tournaments, this could make sense:
"The notion that small differences in age might make a big difference on the field is familiar terrain to Malcolm Gladwell, The New Yorker magazine writer and bestselling author. In his latest book, Outliers: The Story of Success, Gladwell studied ice hockey teams in Canada, where the game is high on the list of national priorities.
By the time kids are just 9 or 10, they are already being selected for elite teams, extra training and top coaching, and at that young age, those born nearest to the January 1 cut-off date - the oldest in each year's grouping - are usually the best, with the extra few months giving them a real advantage on the ice. With more special attention, that advantage seems to stick: Gladwell found that in any grouping of elite hockey players, 40 per cent were born in the first three months of the year. "

This sounds a bit like the reverse of unraveling, the process by which transactions become earlier and earlier in some markets. That process can feed on itself; if everyone else is recruiting early, maybe you had better do so also. It sounds like holding children back from school entry could potentially have the same dynamic: if the other children will all be a year older, maybe you should hold yours back too, especially if you're raising a future football player...

Market for major league baseball players: international trade

The NY Times reports: Japanese Irked at U.S. Interest in Pitching Phenom

"Many Japanese baseball officials are outraged that United States teams are courting Tazawa, a hard-throwing right-handed pitcher, because they insist it is long-established practice for amateurs like him to be strictly off limits to major league clubs..."
"“This was more than just a gentleman’s agreement, but rather an implicit understanding that the major leagues would do no such thing,” Nippon Professional Baseball said in a news release on signing Japanese baseball amateurs. “That a handful of clubs from the majors is trying to break this gentlemen’s agreement is truly regrettable.”
..."The protocol agreement between Major League Baseball and Nippon Professional Baseball does not address the signing of either nation’s amateur players. It does formalize how Japanese veterans may switch continents: on the open market after nine seasons in the Japan major leagues, or earlier if a player’s club chooses to auction off his rights through a procedure commonly known as posting. Established in 1998, posting established stars like Daisuke Matsuzaka has generated as much as $51 million for their Japanese clubs, and losing top amateurs could hurt that pipeline."
..."The Yomiuri official Hidetoshi Kiyotake has said he fears for the viability of the entire Japanese majors should the major leagues descend on his nation’s amateur talent. In a recent issue of the Japanese magazine Weekly Baseball, he wrote that South Korea’s major league has been seriously harmed by 38 amateur players signing directly with major league clubs since 1994.
..."Fearful that Tazawa’s signing such a contract would encourage more Japanese amateurs to follow him, Nippon Professional Baseball recently passed a rule that requires any amateur who jumps to a major league team to sit out two or three years before being able to return to play in Japan."

Market for medical services: time of day

Timing is an important part of many markets: Beth Israel Medical Center in NYC is experimenting with a 24 hour a day clinic for non-emergency services, intended to serve parts of the market that have trouble making appointments during standard doctors' hours: When You Just Have to Get a Flu Shot... at 3 A.M.