Showing posts with label school choice. Show all posts
Showing posts with label school choice. Show all posts

Tuesday, December 26, 2023

Market Design in El Mercurio--Chile's oldest newspaper

Last Tuesday, in Chile I was interviewed by Eduardo Olivares, the editor for Economics and Business of El Mercurio,  which published the interview yesterday. We talked for an hour about market design generally, about how markets work when they're working well or working badly, and we spoke about school choice (where Chile is a leader) and transplantation (where it is not). The interview is behind a paywall, but below are some extracts (retranslated back into English via Google Translate).

On markets generally:

—Many people ask that “markets be free,” as has recently happened in Argentina. Should they be free?

“That's a complicated question. Markets should be free to function well, but they need conditions that allow them to function well. Having a free market does not necessarily mean a market without rules. A wheel can spin freely because it has a well-greased axle and bearings. A wheel by itself cannot turn very well, and the same goes for the market.”

—Who puts the oil in the wheel gears?

“That's the job of market design. Part of what makes markets work well are good market rules. The government has a role in regulating markets, concerning property rights and things like that. But on another level, entrepreneurs do things. Here in Santiago I [can]... call an Uber using the same app and rules I use in California. Uber is a marketplace for passengers and drivers. The rules can be made by both private organizations and the government.”

On prices:

—Do prices matter?

"A lot. “Prices are important to help allocate scarce resources, but also to make them less scarce.”

...

—When do they not matter?

“Let me start with when they matter a lot: in commodity markets. If you want to buy commodities, price is really the only thing that's happening. But when 'El Mercurio' wants to hire journalists, it doesn't limit itself to offering a salary: it wants it to be a good job, with special reporters. Price is important, but in other markets other things are also important. When you get a new job, the first question your friends ask you is not what the salary is, but who you work for.”

On school choice:

“Most markets are not commodity markets... In some markets we don't like prices to work at all. One of the places where Chile is a leader in market design is school choice: how people are assigned to schools and Chile has done a lot of work on this, although mainly for public schools.”

—What do you know about this system in Chile?

“Not long ago, before there was centralized and widespread school choice in Chile, there were the usual problems with decentralized school choice; That is, parents had to get up early to get in line, and they had a difficult process to register their children.”

—The new system has been criticized. Some claim it caused more people to choose the private system over the public school system. Isn't it similar to what is happening in New York, for example?

“There is something to that. In New York and Boston we also have a system that we call charter schools: free access schools, but organized by private entities, even if they are municipal schools. And they also have different standards. School choice is important, but it does not solve the problems of poverty or income inequality. Now, one of the reasons we have school choice in the United States and perhaps also in Chile is because we think that, otherwise, there is a danger that the poor will be condemned to send their children to poor schools. .

—Has there been any successful case in which parents can honestly rank the order of preference for the school they want their children to go to?

“In Chile, procedures are used that [make it] what game  theorists call a dominant strategy to express true preferences. The [remaining] problem is not in creating systems that make it safe to express preferences, but in distributing the information so that people can form preferences sensibly. In the United States, the hardest families to reach are those who don't speak English at home, so it's sometimes difficult to communicate with them. And different families have different feelings about what kind of schools their children should attend.”

“The benefits of school choice come from the fact that some schools may be high quality for some children but not for others, so we would like children to attend the schools that are best quality for them.”

On kidneys:

—You are famous for the proposal that allowed the “kidney exchange.” Years after the first experience, what do you see now in this type of market?

“Kidney exchange is working quite well in the US, but it works especially well for patients who are not too difficult to match. Even in the US, a fairly large country, we have patients who are so difficult to match that we have trouble finding a kidney for them.”

—And in other countries?

“Smaller countries, with 20 million inhabitants, like Chile, would benefit if we could make national borders not so important. When we look at transplants per million inhabitants, Chile is in the middle of the world. But since it is a small country, when the total number of transplants performed is analyzed, Chile has very few. Kidneys are obtained from both deceased and living donors. In Chile, as in much of the world, the majority of transplants come from deceased donors. Kidney exchange would allow more transplants to come from living donors ... “Twenty million is not enough, so it would be very good to see in South America an exchange of kidneys that can cross between countries, which is not so easy to do.”

Equality of exchange and the role of perceptions

“One of the things that worries people when talking about transplants is that [they think it might be] a medical process that exploits the poor. Of course, the thing about kidney exchange is that each pair of people gives one kidney and receives one kidney. It is very egalitarian. I think kidney exchange is a good place to combat this notion that transplantation is like trafficking,” he notes.

—Notions, perceptions are very important. Many people think of “exchange” as the exchange of securities in the stock market.

“That's right, but not every exchange involves money. One of the discussions about money in the world that is taking place in the European Union at the moment is about payment to blood plasma donors. In the EU, only Germany, Austria, the Czech Republic and Hungary pay blood plasma donors. And those are the only EU countries that have as much blood plasma as they need. The others have to import everything, and they do it from the United States. The United States is the Saudi Arabia of blood plasma (…) The World Health Organization says that plasma must be obtained in each country, and from unpaid donors. You have to be self-sufficient... an economist finds that a little funny. Blood is a matter of life and death. “When there is a pandemic, we do not tell countries that they must be self-sufficient [in vaccines].”

—When we talk about these exchanges of blood plasma and kidneys, school choice systems, we are talking about the same idea: coincident or paired markets. But the concept of the market has been so questioned, especially by some political groups, for so long...

"It's true. Now,  kidney exchange is special because money doesn't change hands. Money changes hands to get medical care, you have to pay doctors, nurses and hospitals. But we are not talking about buying kidneys from donors, but rather that, at the patient level, each pair receives a kidney and donates a kidney. It is radically egalitarian. Many people who think about markets may not think of it as a market, but I think that's a mistake. Many markets are not just about money… we would worry much less about markets if income and wealth inequality did not exist. “What worries us about markets is that some people are poor and some people are rich, and markets seem like a way to give the rich an advantage.”

“There is no doubt that being rich is better than being poor. The real question is what do we do to alleviate poverty. Making it invisible is not the same as alleviating it. One of the reasons I think many countries don't allow blood and plasma donors to be paid is because they don't like the way that looks. It reminds them that some people would like to get some money and would donate blood for it.”







Apparently, according to the caption, I'm "affable and smiling" (although not in this picture:)

I was in Chile to participate in what turned out to be a wonderful workshop on market design at the University of Chile, organized by Itai Ashlagi, José Correa, and Juan Escobar.
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Update (Dec. 27): Here's an account of my closing public talk from the U. Chile's Center for Mathematical Modeling, one of the hosts of the market design workshop.

And here's a picture at the close, including some of those mentioned above: At my far left in the picture is José Correa,  who in addition to his other roles is Vice Rector for Information Technologies. Next to him is Alejandra Mizala, prorrector (provost) of the university.  Next to her (immediately to my left) is Rector of the University of Chile, Rosa Devés, and immediately to my right is market designer and director of the MIPP Millennium Institute, Juan Escobar. Next to him is Héctor Ramírez, director of the Center for Mathematical Modeling. And next to him (at my far right) is professor Rafael Epstein who (along with Correa, Escobar, and his daughter Natalie Epstein) has been involved with school choice in Chile, among other things.



Thursday, September 7, 2023

Navigating NYC school choice: advice for families

 Each year a new cohort of families has to navigate school choice in New York City.  The city offers lots of resources for gathering information.  One advantage of employing methods that make it safe to reveal true preference orders is that at least one aspect of the process is straightforward. (Of course, constructing a list of 12 schools out of the many available isn't easy.)

The NY Times offers a guide, which is full of information on how to go about gathering information with which to form preferences over schools:

Applying to N.Y.C. Public Schools Can Feel Daunting. Here’s What to Know. What matters when choosing a school? How should you compare options? And what’s the best strategy for getting your first choice?  By Troy Closson, Sept. 5, 2023,

"What’s the best strategy when applying?

"You should rank schools and programs in order of your true preference. There is no better approach. Students are considered for a lower choice only if a higher ranked school does not have space.

"Admissions experts suggest creating a complete list of 12 schools with a balance of programs, priorities and demand per seat, which you can find on MySchools. Apply by the deadline; there is also no benefit to applying earlier"


HT: Parag Pathak

*******

Another resource:

Abdulkadiroglu, Atila , Parag A. Pathak, and Alvin E. Roth, "Strategy-proofness versus Efficiency in Matching with Indifferences: Redesigning the NYC High School Match,'' American Economic Review, 99, 5, Dec. 2009, pp1954-1978. 

Tuesday, August 15, 2023

Affirmative action in Brazilian universities: guest post by Inácio Bó

 Recent legislation in Brazil addresses university admissions with affirmative action that targets multiple characteristics that individuals may have (in different combinations), namely income, ethnicity, and the type of institution at which they studied. Early attempts to implement such a system produced undesirable outcomes, but recent legislation, informed by market design, is on the path to correcting this. Below, Inácio Bó brings us up to date:

Guest blog post by Inácio Bó

For many decades, Brazilian’s federal universities were—and still are— the top higher education institutions in the country. They had, however, a contradictory combination of circumstances: all of them were public-funded and tuition-free, but their students were overwhelmingly from a minority white higher socio-economic class. In response to that, in 2012 congress passed legislation mandating affirmative action in the access of all such institutions.

Orhan Aygün and I were at that time classmates pursuing our PhD in economics at Boston College. We spent days and weeks looking at the details of the structure of the rules for implementing the law, trying to better understand it. While working on some examples, we noticed that there could in principle be situations that were at odds with the intended objective of the law. Under some circumstances, black and low-income candidates would be rejected from positions where white and high-income candidates would be accepted, despite the former having higher entry-level exam grades than the latter. This  would be an outcome that goes in the opposite direction from the intended objective of helping black and low-income students attend these institutions.

The reason for this problem lies on the method used for implement the affirmative action law in the universities. Seats in each program in each university were split into groups of seats, including “open seats”, “black candidates”, “low-income candidates”, and “black and low-income candidates”. When applying for a program, a candidate would choose one of the alternatives for which she is eligible. The top candidates among those applying for each set of seats, ranked by their grade in a national exam, would be accepted. This method might, however, result in different levels of competition for different seats in the same program, resulting for example in tougher requirements for acceptance for “black and low-income” candidates than for “black” candidates, even if on average low-income candidates have lower grades overall.

In a paper published in the AEJ:Micro in 2021 (Aygün, Orhan, and Inácio Bó. 2021. "College Admission with Multidimensional Privileges: The Brazilian Affirmative Action Case." American Economic Journal: Microeconomics, 13 (3): 1-28.), we showed how this problem can be solved while still satisfying the text and spirit of the affirmative action law in Brazil with small changes in the way by which candidates are selected. (The idea is to order slot-specific priorities so that candidates with protected characteristics can compete for all of those slots for which their characteristics qualify them.) The paper also shows “smoking gun” evidence that these “unfair rejections” were taking place, showing that programs where the cutoff grades for acceptance for each subset of seats were compatible with these rejections constituted almost half of the programs offered across the nation.

While the article gained praise in the academic economic community, our hopes that it would reach the policymakers in Brazil were initially dashed. Despite having the chance of personally visiting the Ministry of Education in 2015 for two weeks, my attempts to talk with those in power were unsuccessful, and people to whom I explained some of our findings deemed its contents “critical of the government”.

 Especially in light of the political developments that took place in Brazil in the years that followed, I had mostly moved on from my hopes of seeing the changes we proposed being implemented.

Things started to change, however, around May of 2022. The staff from the office of representative Tábata Amaral, who is a prominent young politician with a focus on education, were having talks with Ursula Mello, now a professor at the Department of Economics at PUC-Rio in Rio de Janeiro, about some aspects of the affirmative action law related to her work. Given her knowledge about the AEJ:Micro paper, Ursula suggested that I join the discussions. A meeting where this happened even ended up in the press (https://www1.folha.uol.com.br/educacao/2022/05/pesquisadores-defendem-novo-algoritmo-no-sisu-para-nao-prejudicar-cotistas.shtml).

Adriano Senkevics, her co-author in related papers who works at the INEP—an agency connected to the Brazilian Ministry of Education in charge of evaluating educational systems—also joined.

In these discussions, it became clear that if we wanted our ideas to have any chance of gaining traction, we needed to write a policy-oriented paper, focused on the current Brazilian specifics, in Portuguese, and with policy-makers as the audience—not academics.

Adriano and I worked together in that project, now with a much more detailed dataset. We tailored the proposal to the updated law, which also included reservations for candidates with disabilities, and were finally able to quantify the negative impact of the failures we identified. Our estimates indicate that, in the selection process of 2019, at least ten thousand students were “unfairly rejected” from their applications, with more than 8 thousand being left unmatched to any university despite having an exam grade high enough to be accepted for less restrictive reserved seats. These numbers greatly exceeded our expectations, and made a clear political case for a change. The working paper went out in January of 2023 (“Proposal to change the rules for the occupation of quotas in the student entrance to federal institutions of higher education,” by Inácio Bó and Adriano Souza Senkevics).

While the theoretical arguments were already in the AEJ:Micro paper, the proposal had a greater and faster impact in the corridors of the Brazilian capital. Articles in the main newspapers in the country reported on the findings and the proposal (https://oglobo.globo.com/brasil/educacao/enem-e-vestibular/noticia/2023/03/quase-650-candidatos-para-uma-vaga-maiores-concorrencia-do-sisu-estao-entre-os-alunos-cotistas.ghtml

, https://oglobo.globo.com/brasil/antonio-gois/coluna/2023/02/reformar-o-sisu.ghtml

, https://www1.folha.uol.com.br/colunas/rodrigo-zeidan/2023/04/desenhando-mercados.shtml )

People were openly sharing the article on twitter with members of the ministry of education

(https://twitter.com/thiamparo/status/1621189953785839617?s=20 ,

https://twitter.com/mgaldino/status/1621008428763332612?s=20 ). We could feel the momentum.

In the months that followed, I started having regular interactions with members of the Ministry of Education. The text and zoom discussions involved technical and political aspects of changes in the law, which extended beyond the specific changes we suggested.

Different variations of the changes and some alternative proposals were considered. I had to run simulations while flying to deliver them before a meeting that the secretary had with the minister. I also had the incredible experience of joining a meeting at the “Casa Civil”—a department somewhat comparable to the prime minister in a parliamentary system—with the presence of secretaries from multiple ministries , where I presented our proposal and discussed some details and scenarios. Around that time, and without our knowledge, a senator presented a bill explicitly based on our proposal (https://www25.senado.leg.br/web/atividade/materias/-/materia/156995 ).

By the end of June, our belief that the changes would be implemented became stronger. Since our proposal was (by design) already compatible with the quotas law, its implementation could be done even in the absence of new legislation, and there was clear interest on the part of those in charge for making it happen.

A momentous event in this journey, however, took place on August 9th.

Because of a series of political circumstances, an urge to pass a renewed law for the affirmative action led to a bill proposed by Representative Dandara—the first member of congress who herself benefitted from the quotas law—to be brought to the floor for a vote.

Among other changes, it made the affirmative action policy permanent, changed the order in which seats are filled, and included text that should, in the following secondary legislation, include text that describes our proposal. As if emotions were not high enough, we had urgent calls to send the text of our proposal to members in the floor of congress minutes before the vote took place. And this resulted in the photo below, showing Dandara giving a speech before the vote, with a page from our paper in her hand.


The journey is not yet over. The bill must still pass the senate, and the legislation with the implementation details will follow. But I learned that these changes are made of so many steps that one has to choose one as the turning point. We believe that this is a good one.

The INEP (National Institute of Educational Studies and Research) thinks so too: (https://www.gov.br/inep/pt-br/assuntos/noticias/linha-editorial/inep-contribui-com-atualizacao-da-lei-de-cotas)

Tuesday, July 25, 2023

Incentives in matching markets: Counting and comparing manipulating agents by Bonkoungou and Nesterov

 Here's a paper that caught my eye in the current issue of Theoretical Economics, Volume 18, Issue 3 (July 2023)

Incentives in matching markets: Counting and comparing manipulating agents by Somouaoga Bonkoungou and Alexander Nesterov

Abstract: Manipulability is a threat to the successful design of centralized matching markets. However, in many applications some manipulation is inevitable and the designer wants to compare manipulable mechanisms to select the best among them.  We count the number of agents with an incentive to manipulate and rank mechanisms by their level of manipulability. This ranking sheds a new light on practical design decisions such as the design of the entry-level medical labor market in the United States, and school admissions systems in New York, Chicago, Denver, and many cities in Ghana and the United Kingdom.

"First, we consider the college admissions problem where both students and schools are strategic agents (Gale and Shapley (1962)) and schools can misreport their preferences as well as their capacities. We show that when all manipulations (by students as well as by schools) are considered, the student-proposing Gale–Shapley (GS) mechanism has the smallest number of manipulating agents among all stable matching mechanisms (Theorem 1). Dubins and Freedman (1981) and Roth (1982) show that this mechanism is not manipulable by students. This result was one of the main arguments in favor of its choice for the NRMP. However, it also has the largest number of manipulating schools among all stable mechanisms (Pathak and Sönmez (2013)). Our result still supports its choice when all strategic agents are considered. What is more, it is still the best choice even when schools can only misreport their capacities, but not their preferences. All these conclusions carry over to the general model where, in addition, students face ranking constraints: although the student-proposing GS mechanism is now manipulable by students, it is still the least manipulable mechanism.

"Second, we consider the school choice problem (Abdulkadiroglu and Sönmez ˘ (2003)) where students are the only strategic agents and also face ranking constraints. Historically, many school choice systems have used the constrained immediate acceptance (Boston) mechanism, but over time shifted toward the constrained student proposing GS mechanisms and relaxing the constraint. We demonstrate that the number of manipulating students (Theorem 2) weakly decreased as a result of these changes."


Monday, July 17, 2023

Affirmative action in India

 Here's an interesting paper by Orhan Aygün and Bertan Turhan. It comes with something of a backstory, which accounts for its quite delayed publication (delays both in initial acceptance and then in publication after acceptance*). I gather it will appear in the next issue of Management Science.

How to De-Reserve Reserves: Admissions to Technical Colleges in India by Orhan Aygün and Bertan Turhan, Management Science (forthcoming),  Published Online:11 Nov 2022 https://doi.org/10.1287/mnsc.2022.4566

Abstract: "We study the joint implementation of reservation and de-reservation policies in India that has been enforcing comprehensive affirmative action since 1950. The landmark judgment of the Supreme Court of India in 2008 mandated that whenever the OBC category (with 27% reservation) has unfilled positions, they must be reverted to general category applicants in admissions to public schools without specifying how to implement it. We disclose the drawbacks of the recently reformed allocation procedure in admissions to technical colleges and offer a solution through “de-reservation via choice rules.” We propose a novel priority design—Backward Transfers (BT) choice rule—for institutions and the deferred acceptance mechanism under these choice rules (DA-BT) for centralized clearinghouses. We show that DA-BT corrects the shortcomings of existing mechanisms. By formulating India’s legal requirements and policy goals as formal axioms, we show that the DA-BT mechanism is unique for the concurrent implementation of reservation and de-reservation policies."


*This paper spent a long time waiting to be published, because of what seems to have been a priority dispute that, after the paper was accepted for publication,  was pursued through  allegations of research misconduct. The editorial office of Management Science conducted an investigation that determined that there was no reason not to proceed with publication.

Thursday, June 15, 2023

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

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

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

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

...

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



********

Recall also, 

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

Tuesday, April 4, 2023

The Robert Rosenthal Memorial Lecture for 2023 at BU, by Parag Pathak

 Parag Pathak gave this year's Robert Rosenthal Memorial Lecture at Boston University. The title of his talk is “Still Worth the Trip? The Evolution of School Busing in Boston” 

(The video below may undergo some further editing, but right now it starts with introductions at minute 3.) 


You can also find the Rosenthal lectures from previous years at the link.

(I had the honor of giving the 2007 lecture... Bob Rosenthal and I are academic siblings, we were both advised by Bob Wilson.)

Monday, January 16, 2023

School choice, by Atila Abdulkadiroğlu and Tommy Andersson

 Here's what looks to be a magisterial survey of school choice by two pioneers of the theory and practice of market design.

School choice by Atila Abdulkadiroğlu and Tommy Andersson, Handbook of the Economics of Education, Available online 3 January 2023, https://doi.org/10.1016/bs.hesedu.2022.11.001 

Abstract: School districts in the United States and around the world are increasingly moving away from traditional neighborhood school assignment, in which pupils attend closest schools to their homes. Instead, they allow families to choose from schools within district boundaries. This creates a market with parental demand over publicly-supplied school seats. More frequently than ever, this market for school seats is cleared via market design solutions grounded in recent advances in matching and mechanism design theory. The literature on school choice is reviewed with emphasis placed on the trade-offs among policy objectives and best practices in the design of admissions processes. It is concluded with a brief discussion about how data generated by assignment algorithms can be used to answer contemporary empirical questions about school effectiveness and policy interventions.

Wednesday, November 2, 2022

Managing inter-district school choice, by Yuchiro Kamada and Fuhito Kojima

 Here's a paper that considers inter-district school choice, motivated by Tokyo day care centers.  I think  a similar problem arises in the EU in allocating foreign study opportunities for college students.

 Ekkyo Matching: How To Connect Separate Matching Markets For Welfare Improvement  By Yuichiro Kamada And Fuhito Kojima

Abstract. "We consider a school-choice matching model that allows for inter-district transfer of students, with the “balancedness” constraint: each student and school belongs to a region, and a matching is said to be balanced if, for each region, the outflow of students from that region to other regions is equal to the inflow of students from the latter to the former. Using a directed bipartite graph defined on students and schools, we characterize the set of Pareto efficient matchings among those that are individually rational, balanced and fair. We also provide a polynomial-time algorithm to compute such matchings. The outcome of this algorithm weakly improves student welfare upon the one induced when each region independently organizes a standard matching mechanism"

" In Japan ... allocation of slots at accredited daycares are conducted by individual municipal governments and, with few exceptions, a child can only attend a daycare in the municipality of their residence. The City of Tokyo, for example, is divided into 23 small municipalities ... and each conducts a matching independently. Due to the small sizes of the regions, many families would find inter-district admissions—which is called the ekkyo admission ... to be a viable option. Moreover, as a large metropolitan area, many people cross a city boundary to commute, making it potentially more convenient to put their children to a daycare center close to their workplace"


Thursday, October 20, 2022

School choice consulting in New York City

 It is a truth universally acknowledged that any stressful process in which affluent people participate must be in need of a consulting industry.

New York City's school choice processes are no exception:

The School-Admissions Whisperer Joyce Szuflita can assuage Brooklyn’s most anxious parents.  By Caitlin Moscatello

"For the better part of two decades, Szuflita has demystified the process of public-school admissions for some of Brooklyn’s most overwhelmed, optimization-prone parents. ... Prekindergarten and elementary admission are largely based on where you live. But the game gets significantly more byzantine come middle school and more complex yet for high school, with its tier of “screened” institutions that have traditionally required students to test in, audition, or undergo other high-stress assessments. The process of getting into certain schools — and don’t kid yourself, everybody wants in — has long been a brutal one. Until it got slightly easier. And then brutal again. Or maybe some middle level of brutal? This is why parents need Szuflita.

...

"On September 29, schools chancellor David C. Banks abruptly announced that some of the city’s most prestigious middle and high schools would move away from an open lottery system and increase their use of merit-based admissions. The approach prioritizes students with an A average — children Banks calls “hardworking,” a loaded description in a city with one of the greatest wealth disparities in the country — and reverses the previous mayor’s strategy, which aimed to usher more lower-income students into New York’s top schools.

...

“The pendulum is swinging back a little bit,” Szuflita says of the Banks announcement, insisting that the changes are not as sweeping as they might seem. “The algorithm is still exactly the same.” Contrary to how some have read the news, the old lottery is still partially in use. The random number (a hexadecimal, actually) that each student is assigned works as a tiebreaker to get into screened high schools and can sometimes be a major factor when families submit their ranked choices of preferred schools.

"Clients often panic about their lottery numbers and want to change the ranking of their list, which Szuflita doesn’t recommend for anyone except those with exceptionally high or low numbers. Trying to outsmart the process, she says, is pure “magical thinking.” She’s constantly telling parents to trust the fairness of the city’s sorting algorithm, whose authors literally won the Nobel Prize, and rank in true preference order. (Or, as she tends to put it in emails: “RANK IN TRUE PREFERENCE ORDER!!!!!!!”) Despite this, clients sometimes persist, asking, How do we work the algorithm to our advantage? How do we strategize ranking our list? “That’s when I yell at people in the nicest way,” she says, because they don’t know what they’re talking about and they’re cutting into her time. “Like, ‘No, shut up. Shut up and listen to me. You’re not going to get everything you need to know.’” But most of her consults take two hours, she says, and don’t involve a lot of back-and-forth. “They tell me about their children and then what follows is usually a rapid-fire, two-hour information dump from me. There is not a lot of airing of concerns, because I already anticipate their concerns.” The download is intensely specific, tailored to each family and covering individual schools, principals, teachers, and facility upgrades few people are aware of. She verifies rumors (or sets the record straight) and knows things you can’t find on the internet."

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Related recent post:

Sunday, October 2, 2022


Sunday, October 2, 2022

Return to previous school assignment policies (in some respects) under New York City's new mayor

 In NYC, the pendulum is still swinging between inclusive admissions as measured by demographics and determined by lottery, and meritocratic admissions as measured by tests and grades.

The NYT has the story:

In a Reversal, New York City Tightens Admissions to Some Top Schools. The city loosened selection criteria during the pandemic, policies some parents protested as unfair and others hoped would reduce racial disparities. By Troy Closson

"New York City’s selective middle schools can once again use grades to choose which students to admit, the school chancellor, David C. Banks, announced on Thursday, rolling back a pandemic-era moratorium that had opened the doors of some of the city’s most elite schools to more low-income students.

...

"New York City has used selective admissions for public schools more than any school district in the country. About a third of the city’s 900 or so middle and high schools had some kind of admissions requirement before the pandemic disrupted many measures to sort students by academic performance.

...

"Selective high schools will also be able to prioritize top-performing students.

"The sweeping move will end the random lottery for middle schools, a major shift after the previous administration ended the use of grades and test scores two years ago. At the city’s competitive high schools, where changes widened the pool of eligible applicants, priority for seats will be limited to top students whose grades are an A average.

...

"The announcement came as New York City’s education officials are confronting multiple crises in the wake of the pandemic, complicating a dilemma that has bedeviled previous administrations: how to create more equitable schools, while trying to prevent middle-class families from abandoning the system.

"State standardized test scores released Wednesday showed that many students fell behind, particularly in math, and that many Hispanic, Black and low-income students continue to lag far behind their white, Asian and higher-income peers. At the same time, the district is bleeding students: Roughly 120,000 families have left traditional public schools over the past five years. Some have left the system, and others have gone to charter schools."

*****

And here's the Washington Post:

New York City, embracing merit, rolls back diversity plan for schools By Laura Meckler

"New York City schools announced Thursday they would allow middle schools to consider academics in admitting students to some of the city’s most sought-after programs, unraveling pandemic-era rules aimed at injecting racial and economic diversity into a segregated system.

"High schools would also rely more heavily on merit and less on the luck of a lottery under the new plan, reversing the previous administration’s direction as a new mayor takes command of the nation’s largest school system.

...

"In San Francisco, admissions into the elite Lowell High School were converted from merit-based into a lottery system. As in New York, though, the change was reversed — in this case, after several school board members were recalled, in part over this issue.

"In Northern Virginia, Thomas Jefferson High School for Science and Technology also shifted from an admissions test to a “holistic review” that considers several factors, a move that is being challenged in court and has faced resistance from the Republican governor and his administration.

...

"In New York, the debate is particularly fiery because students are required to apply to middle and high school, and before the pandemic, about a third of the city’s 900 middle and high schools included requirements for admission — such as grades, test scores, attendance and behavior records. 

...

"That system was largely converted into a lottery under Mayor Bill de Blasio.

"For high school, applicants were put into tiers based on their grades. But the top tier included about 60 percent of all students, who had the first crack at the top schools. Competitive schools drew acceptances randomly from this group.

...

"Now, under the new system announced Thursday, it will be harder to get into the top tier, though once in that group, it will still be a lottery. To get into the top tier, students must be in the top 15 percent of their school or of the city overall, and they must have at least a 90 percent on grades.

"Test scores, which had been used for years but also criticized as biased, will not be considered. Banks said exam scores are a flawed measure but grades are “still a very solid indicator of how you are showing up as a student,” even for students who face hardships at home."

Friday, September 23, 2022

Choosing between public and private schools: vouchers in Arizona

There's a fight over public versus private school funding in Arizona. Here's the background:

Arizona OKs Biggest US School Voucher Plan, Faces Challenge. Republican Gov. Doug Ducey has signed a massive expansion of Arizona’s private school voucher system.  AP, July 7, 2022

"Republican Gov. Doug Ducey on Thursday signed a massive expansion of the state’s private school voucher system, even as he faced a promised effort by public school advocates to block the bill and ask voters to erase it during November’s election.

"The expansion Ducey signed will let every parent in Arizona take public money now sent to the K-12 public school system and use it to pay for their children’s private school tuition or other education costs.

...

"Ducey has championed “school choice” during his eight years in office. He signed a universal voucher expansion in 2017 with enrollment caps that was referred to the ballot by a grassroots group called Save Our Schools Arizona.

"Voters soundly rejected the expansion by a 2-to-1 vote in the 2018 election, but advocates of what are formally called “Empowerment Scholarship Accounts” pushed ahead with new expansions anyway. The universal voucher bill passed with only support from majority Republican lawmakers in the legislative session that ended early on June 25."

**********

And Salon brings us up to date:

Arizona's school privatization battle heats up: Will the voters get to decide?  Republicans' massive school voucher plan may yet be defeated (again) — but the challenge is stiffer this time By KATHRYN JOYCE, SEPTEMBER 20

"A fight over the future of the most sweeping school voucher program in the country has heated up in Arizona over the last few weeks, as public school advocates race to gather enough signatures to trigger a ballot referendum aimed at overturning a voucher law recently passed by the state's Republican-dominated legislature. The referendum campaign, which faces a crucial deadline this Friday, has drawn intense opposition from Arizona conservatives. This has included funding for multiple anti-referendum websites, roadside protests starring Republican legislators and, over the last two weeks, conflicts between activists both on social media and in the streets. 

...

"Under the new law, any Arizona parent who opts their children out of public school will receive a debit card with an average balance of just under $7,000, which they can use to spend on almost any educational needs they choose, from private school tuition to homeschooling expenses to buying computers to hiring private teachers for "microschools." Public education advocates immediately warned that such a huge transfer of public funds to private hands could be the death knell for public schools, which would likely have to make untenable cuts to teaching staff and school programs.

...

"From the inception of Arizona's ESAs, critics have charged that they're little more than a workaround to funnel public tax dollars to private schools. The idea was born after a court found in 2009 that two earlier Arizona school voucher programs were unconstitutional, violating the state's prohibition on using public money for private education. In 2011, under the guidance of the Goldwater Institute, a conservative think tank, the state launched an ingenious alternative: sending state funds directly to parents, who spend the money as they see fit. The ESA option then became a nationwide model, copied in numerous other states and increasingly seen by conservative education reform activists as "the purest form of school choice." 


HT: Bertan Turhan


Friday, August 5, 2022

Busing for schools in Boston and NYC, by Angrist, Gray-Lobe, Idoux & Pathak

 One of the spinoffs of the design of school choice systems in Boston, NYC and elsewhere is that it has opened up the empirical study of school effectiveness, by allowing economists to use some randomness in the assignments while controlling for family preferences to distinguish school effects from student selection.  It has turned out that it's hard to change test scores through school assignments, and neighborhoods remain important. But integration responds to voluntary choice, although the paper below doesn't find effects on college attendance after controlling for the selection of travel by students.

Still Worth the Trip? School Busing Effects in Boston and New York by Joshua Angrist, Guthrie Gray-Lobe, Clemence M. Idoux & Parag A. Pathak, NBER WORKING PAPER 30308  DOI 10.3386/w30308  July 2022

Abstract: "School assignment in Boston and New York City came to national attention in the 1970s as courts across the country tried to integrate schools. Today, district-wide choice allows Boston and New York students to enroll far from home, perhaps enhancing integration. Urban school transportation is increasingly costly, however, and has unclear integration and education consequences. We estimate the causal effects of non-neighborhood school enrollment and school travel on integration, achievement, and college enrollment using an identification strategy that exploits partly-random assignment in the Boston and New York school matches. Instrumental variables estimates suggest distance and travel boost integration for those who choose to travel, but have little or no effect on test scores and college attendance. We argue that small effects on educational outcomes reflect modest effects of distance and travel on school quality as measured by value-added."


"School transportation expenditures today are driven in part by the fact that many large urban school districts allow families to choose schools district-wide, lengthening school commutes for some. District-wide  choice  is  a  feature  of  school  assignment  in  Boston,  Chicago,  Denver,  Indianapolis,Newark,  New Orleans,  Tulsa,  and Washington,  DC, to name a few.  In choice districts,  seats at over-subscribed schools are typically allocated by algorithms that reflect family preferences in the form of a rank-order list and a limited set of school priorities.  ...  Choice in large urban districts is appealing because choice systems potentially decouple school assignment from underlying residential segregation.  Moreover, where school quality is unevenly distributed over neighborhoods, district-wide choice affords all students a shot at schoolsviewed as high-quality.

"This  paper  asks  whether  school  travel  in  the  modern  choice  paradigm  is  working  as  hoped, boosting integration and learning, especially for minority students.  Our investigation focuses on Boston and New York, two cities of special interest because of their high transportation costs and because they’ve long been battlegrounds in the fight over school integration.  We estimate the effects of non-neighborhood school enrollment for students for whom school travel is facilitated by school choice.  In both cities, students who opt for non-neighborhood schooling have higher test scores and are more likely to go to college than those who travel less.  But these estimates may reflect selection bias arising from the fact that more motivated or better-off families are more likely to travel. 

"We  solve  the  problem  of  selection  bias  using  the  conditional  random  assignment  to  schools embedded in Boston and New York’s school matching algorithms.  A given student may be offered a seat at a school in his or neighborhood, or a seat farther away.  Conditional on an applicant’s preferences  and  school  priorities,  modern  choice  algorithms  randomize  seat  assignment,  thereby manipulating distance and travel independently of potential outcomes.

...

" A parsimonious explanation for our findings, therefore, is that travel facilitates integration but does not translate into large enough changes in value-added to change education outcomes much."

Monday, July 25, 2022

Efficient school choice when schools are not players: Phil Reny in the AER

 In some school choice systems, such as in New York City, the schools (represented e.g. by the school principals) as well as the students and families are strategic players. I think the weight of the evidence in those cases clearly points to the importance of having stable matchings, to forestall various forms of strategic behavior by blocking pairs.  

But in many school choice systems the individual schools (although not necessarily the school district) are not strategic players. In those, the school choice problem can usefully be viewed as a problem of allocating objects, namely school places, and only the students and their families are participants for whom we should have incentive and welfare concerns. In these cases, pairwise stability of the matching may be a fairness consideration, but not one with critical strategic or welfare implications.  A Pareto improvement in this case is one that improves matches according to student preferences--the priorities that schools have over students are part of the mechanism, but they don't have welfare consequences.

Here's a nice recent paper by Phil Reny which considers that latter situation, and investigates an outcome that improves student welfare compared to stable matchings, while still making a substantial bow to fairness of the sort captured by stability.  His results give new insight into the mechanism proposed by Onur Kestin in his famous 2010 paper in the QJE*.

Reny, Philip J. "Efficient Matching in the School Choice Problem." American Economic Review 112, no. 6 (2022): 2025-43.

Abstract: "Stable matchings in school choice needn’t be Pareto efficient and can leave thousands of students worse off than necessary. Call a matching μ priority-neutral if no matching can make any student whose priority is violated by μ better off without violating the priority of some student who is made worse off. Call a matching priority-efficient if it is priority-neutral and Pareto efficient. We show that there is a unique priority-efficient matching and that it dominates every priority-neutral matching and every stable matching. for every student in the mechanism that selects the priority-efficient matching"

##############

*Kesten, Onur. "School choice with consent." The Quarterly Journal of Economics 125, no. 3 (2010): 1297-1348.

############

So I think we're now seeing a dialog between two approaches to improving student welfare in school choice environments in which pairwise stability (avoiding blocking pairs consisting of schools and students/families) doesn't seem critical to success (i.e. environments in which schools aren't able to participate in blocking pairs).  Reny and Kesten present a path towards doing that while paying a lot of respect to the priorities that schools have for students. (The success of the deferred acceptance algorithm even in these environments may have a lot to do with the fact that school administrators are often quite invested in the priorities that schools are specified to have over students, since these are intended to shape who goes to which schools.)

The alternative approach looks at an efficient and strategy-proof mechanism like top trading cycles  (TTC) that pays some respect to those priorities, but not at the expense of strategy-proofness, i.e. while keeping it completely safe for students/families to state their true preferences straightforwardly.

For that discussion, see this previous post:

Wednesday, December 9, 2020

***********
Update: Péter Biró alerts me to this recent paper that also relates to my concluding comments above.

Biró, P. and Gudmundsson, J., 2021. Complexity of finding Pareto-efficient allocations of highest welfare. European Journal of Operational Research, 291(2), pp.614-628.

Abstract: We allocate objects to agents as exemplified primarily by school choice. Welfare judgments of the object-allocating agency are encoded as edge weights in the acceptability graph. The welfare of an allocation is the sum of its edge weights. We introduce the constrained welfare-maximizing solution, which is the allocation of highest welfare among the Pareto-efficient allocations. We identify conditions under which this solution is easily determined from a computational point of view. For the unrestricted case, we formulate an integer program and find this to be viable in practice as it quickly solves a real-world instance of kindergarten allocation and large-scale simulated instances. Incentives to report preferences truthfully are discussed briefly.

Sunday, July 24, 2022

School choice in Amsterdam: a counterfactual analysis

 Forthcoming in the JPE (It looks like the refereeing process worked its magic on this paper, whose first version was distributed in 2015...):

Haan, Monique De, Pieter Gautier, Hessel Oosterbeek, and Bas Van der Klaauw. "The performance of school assignment mechanisms in practice." 

This is the author’s accepted manuscript without copyediting, formatting, or final corrections. It will be published in its final form in an upcoming issue of Journal of Political Economy, published by The University of Chicago Press. Include the DOI when citing or quoting: https://doi.org/10.1086/721230  Copyright 2022 The University of Chicago Press.

Abstract: "We use a unique combination of register and survey data from Amsterdam to investigate the performance of school assignment mechanisms in practice. We find that Deferred Acceptance (DA) results in higher mean welfare than the adaptive Boston mechanism. This is due to students making strategic mistakes. The welfare gain o fa switch from actual Boston to DA is over 90 percent of the welfare difference be-tween actual Boston and optimal (proxy) Boston. Disadvantaged and lower ability students would benefit most from such a switch."

"We contribute to the existing literature by complementing register data of the actual choices of secondary-school students in Amsterdam with survey information from the same students. Students’ actual choices reveal their behavior under the Amsterdam version of the Boston mechanism, where students apply in the first round to one school and ties are broken by lotteries. The survey asks students to rank schools according to their true preferences. For each of the ranked schools, the survey asks students to give preference points that reflect the valuation of these schools relative to the valuation of their most-preferred school. The data enable us to (i) quantify the welfare differences between Boston and DA without making strong assumptions about beliefs and choice behavior,(ii) identify the students who are revealed-strategic under the manipulable mechanism,(iii) identify which students make mistakes in their application choices, separately for students who are revealed-strategic and those who are not, (iv) investigate what type of students are hurt (the most) by making suboptimal choices under the Boston mechanism, and (v) quantify the welfare gain of Boston without mistakes (optimal Boston) relative to actual Boston and DA."


Saturday, June 25, 2022

San Francisco's Lowell High School admissions will return to merit-based system

 The SF Chronicle has the latest twist in this involved story over San Francisco's elite Lowell High School.

Lowell High School admissions will return to merit-based system after S.F. school board vote  by Jill Tucker

"After nearly two years of intense and bitter debate, test scores and grades will once again determine which San Francisco students are admitted to Lowell High School after the city’s school board decided to return to the merit-based admission system Wednesday.

"In a 4-3 vote, the school board decided to restore the previous merit process after two years of using a lottery-based system. The vote will now apply to freshman entering in the fall of 2023 as well as future classes, unless the board takes further action in the future to change the admission process.

...

"The board’s decision was the latest inflection point in the nearly two-year saga featuring feuding public officials, a lawsuit and accusations of racism over which students are eligible to attend Lowell, long considered one of the highest-performing public high schools in the country.

"The board first approved a switch to a lottery system in October 2020, citing a lack of academic data given the switch to distance learning earlier that year.

"A board majority then made that decision permanent four months later, citing a lack of diversity and racism at the elite academic schools. But the hurried vote sparked a lawsuit and then a judge’s ruling that the district violated laws related to the Brown Act, which regulate public meetings.

"The board then had to backpedal, reversing the decision before extending the lottery process for another year."

***********

Earlier:

Sunday, April 17, 2022

Friday, June 24, 2022

New York City school choice: increased use of lotteries in the news

The recent emphasis on lotteries in NYC school choice is discussed in the NY Times:

N.Y.C. Tried to Fix High School Admissions. Some Parents Are Furious. In an attempt to democratize schools, the city is focusing less on grades, attendance and test scores. Instead, it relies heavily on a lottery.  By Ginia Bellafante

"Some back story: Apart from what are known as the specialized high schools — hypercompetitive institutions like Stuyvesant and Bronx Science that, controversially, admit students on the basis of a single standardized test — the city gives eighth graders the option of applying to 160 screened high schools and programs that have their own criteria.

"Whether a student qualifies for one of these selective schools has typically depended on an opaque combination of grades, test scores (different from the ones used for the specialized high schools), essays, art portfolios and other work. The next step has students rank their preferences in descending order on a scale of one to 12, after which they are thrown into a lottery. A prizewinning algorithm developed to match medical students to residency programs then determines where a student is placed.

"Among high-achieving families in Manhattan, brownstone Brooklyn and many parts of Queens, the goal is not a spot in just any of the 160 schools but admission to eight or nine that are especially competitive, prestigious and largely dominated by white and Asian families. What has caused such ire in the current admissions cycle is that many parents discovered that their children — students with grade-point averages in the high 90s, for instance — were admitted to none of their ranked choices. Instead they would be funneled to schools they knew little about.

...

"The state exams, usually a determining factor in high school placements, had been abandoned during the pandemic. So, too, were attendance records. Students with grades in the mid-80s were now bundled with those who had much higher averages, meaning that an eighth-grader with an academically stellar record but a poor lottery number could easily lose out to a merely very good student with a great lottery assignation."

**********

Previous related posts:

Monday, April 18, 2022


Thursday, June 23, 2022

School Choice in Chile

 Here's a recent report on the implementation of centralized school choice in Chile.

School Choice in Chile by José Correa, Natalie Epstein,  Rafael Epstein, Juan Escobar, Ignacio Rios, Nicol ́as Aramayo, Basti ́an Bahamondes, Carlos Bonet, Martin Castillo, Andres Cristi, Boris Epstein, and Felipe Subiabre, OPERATIONS RESEARCH Vol. 70, No. 2, March–April 2022, pp. 1066–1087

Abstract. "Centralized school admission mechanisms are an attractive way of improving social welfare and fairness in large educational systems. In this paper, we report the design and implementation of the newly established school choice system in Chile, where over 274,000 students applied to more than 6,400 schools. The Chilean system presents unprecedented design challenges that make it unique. First, it is a simultaneous nationwide system, making it one of the largest school choice problems worldwide. Second, the system is used for all school grade levels, from prekindergarten to 12th grade. One of our primary goals is to favor the assignment of siblings to the same school. By adapting the standard notions of stability, we show that a stable assignment may not exist. Hence, we propose a heuristic approach that elicits preferences and breaks ties between students in the same priority group at the family level. In terms of implementation, we adapt the deferred acceptance algorithm as in other systems around the world."


"From a practical standpoint, a key lesson is that maintaining continuous communication and collaboration with policymakers is essential, as many practical issues arise and must be incorporated into the design. In addition, decomposing the implementation into a given number of steps allowed us to gain experience, solve unexpected problems, and continuously improve the system. "

Friday, June 10, 2022

Congratulations to Arthur Lee, on receiving the Anna Laura Myers Prize for Outstanding Honors Thesis

Arthur Lee received the Economics Department's Anna Laura Myers Prize for Outstanding Honors Thesis yesterday, for his thesis on school choice in Singapore:

A Multi-Phase School Choice Mechanism: Theory and Practice by Arthur Lee

Abstract: We study aspects of a multi-phase school choice system used to allocate students to primary schools (first to sixth grade) in Singapore. We first examine the institutional objectives and contextual constraints of the market. Using interviews and public sources, we then present evidence of strategic decision-making by parents, and outline common considerations they face. We then introduce a novel theoretical model of a sequential matching mechanism, and analyze its performance under uncertainty. We find that the sequential nature of the mechanism may permit equilibrium welfare improvements for students when compared to the static Boston Mechanism. However, we also find that in some important respects (e.g. stability of equilibrium outcomes), such a system may be less desirable than a slot-specific Deferred Acceptance mechanism, a variant of Deferred Acceptance that allows for quotas. We use empirical evidence to demonstrate, using a Regression Discontinuity Design (RDD) inspired approach, that many parents use prior year’s application information in strategic decision-making. We make partial progress towards additional empirical questions, such as explaining a spike in unassigned students in 2020. Finally, we use our data to provide recommendations for students and parents in their decision-making process.



Congratulations on a fine thesis, Arthur.

Saturday, May 21, 2022

Iowa State University celebrates Bertan Turhan

 The Iowa State University News Service has an article about the market design work of Bertan Turhan.

New model could improve matches between students and schools

"For the majority of students in the U.S., residential addresses determine which public elementary, middle, or high school they attend. But with an influx of charter schools and state-funded voucher programs for private schools, as well as a growing number of cities that let students apply to public schools across the district (regardless of zip code), the admissions process can turn into a messy game of matchmaking.

"Simultaneous applications for competitive spots and a lack of coordination among school authorities often result in some students being matched with multiple schools while others are unassigned. It can lead to unfilled seats at the start of the semester and extra stress for students and parents, as well as teachers and administrators.

"Assistant Professor of Economics Bertan Turhan at Iowa State University and his co-authors outline a way to make better, more efficient matches between students and schools in their new study published in Games and Economic Behavior. Turhan says their goal was to create a fairer process that works within realistic parameters.

“There are a lot of success stories in major U.S. cities where economists and policymakers worked together to improve school choice,” said Turhan. “The algorithm we introduced builds on that and could give school groups some degree of coordination and significantly increase overall student welfare in situations where there’s a lot of competition to get into certain schools.” 

...

"Over the next year, Turhan and his team will be studying the implementation of their model in India where two types of colleges have revamped their admissions process."

********

Here's the paper that was the occasion of the story:

Parallel markets in school choice by Mustafa Oğuz Afacan, Piotr Evdokimov, Rustamdjan Hakimov, and Bertan Turhan

Games and Economic Behavior, Volume 133, May 2022, Pages 181-201, https://doi.org/10.1016/j.geb.2022.03.003Get rights and content

Abstract: When applying to schools, students often submit applications to distinct school systems that operate independently, which leads to waste and distortions of stability due to miscoordination. To alleviate this issue, Manjunath and Turhan (2016) introduce the Iterative Deferred Acceptance mechanism (IDA). We design an experiment to compare the performance of this mechanism under parallel markets (DecDA2) to the classic Deferred Acceptance mechanism with both divided (DecDA) and unified markets (DA). Consistent with the theory, we find that both stability and efficiency are highest under DA, intermediate under DecDA2, and lowest under DecDA. While IDA is not strategy-proof, we show theoretically that strategic reporting can only lead to improved efficiency for all market participants. The experimental results are consistent with this prediction. Our findings cast doubt on whether strategy-proofness should be perceived as a universal constraint to market mechanisms.