Showing posts with label market design. Show all posts
Showing posts with label market design. Show all posts

Sunday, September 10, 2023

Nudges, shoves, regulations and designs: debate in Behavioral and Brain Sciences

Do "nudges" provide low cost solutions to big economic problems? Are they crowding out more effective, but harder or more expensive approaches?

The latest volume of Behavioral and Brain Sciences, Volume 46 - 2023, (a journal optimized to achieve impact factor, which counts references to previously published articles) contains 34 responses to the (previously published) target article*

The i-frame and the s-frame: How focusing on individual-level solutions has led behavioral public policy astray

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Here are two of the responses that might be of most direct interest to regular readers of this blog:

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The issue includes two separate responses by the authors of Nudge:

And here's a reply to all the commentary by the authors of the target article:

*Earlier post:

Thursday, June 16, 2022

 

Monday, July 24, 2023

Algorithms, Approximation, and Learning in Market and Mechanism Design" November 6-9, 2023 in Berkeley (register for funding)

 Here's the announcement

Register for SLMath (MSRI) Workshop: "Algorithms, Approximation, and Learning in Market and Mechanism Design"  November 6-9, 2023 in Berkeley, California, Simons Laufer Mathematical Sciences Institute (SLMath)

Priority Funding Application Deadline: August 31, 2023

Speakers:

Monday, November 6, 2023: Matching Markets without Money

  • Jiehua Chen (Technische Universität Wien)
  • Federico Echenique (University of California, Berkeley)
  • David Manlove (University of Glasgow)
  • Alvin E. Roth (Stanford University)
  • Jaychandran Sethuraman (Columbia University)

Tuesday, November 7, 2023: Non-Convex Auction Markets

  • Elizabeth Baldwin (Merton College, University of Oxford)
  • Paul Milgrom (Stanford University)
  • Shmuel Oren (University of California, Berkeley)
  • Rakesh Vohra (University of Pennsylvania)
  • Yinyu Ye (Stanford University)

(Attendee reception follows Tuesday's events)

Wednesday, November 8, 2023: Algorithmic Mechanism Design

  • Dirk Bergemann (Yale University)
  • Michal Feldman (Tel-Aviv University)
  • Jason Hartline (Northwestern University)
  • Roger Myerson (University of Illinois, Chicago)
  • Sigal Oren (Ben Gurion University of the Negev)

Thursday, November 9, 2023: Learning in Games and Markets

  • Michael Jordan (University of California)
  • David Parkes (Harvard University)
  • Lillian Ratliff (University of California, Berkeley)
  • Tuomas Sandholm (Carnegie Mellon University)
  • Eva Tardos (Cornell University)

Tuesday, July 4, 2023

Market shaping ideas sought at U. Chicago

 The Market Shaping Accelerator at the University of Chicago is seeking to find innovative proposals: MSA Innovation Challenge 2023

"MSA’s inaugural Innovation Challenge 2023 will award up to $2,000,000 in total prizes for ideas that identify areas where a pull mechanism would help spur innovation in biosecurity, pandemic preparedness, and climate change, and for teams to design that incentive mechanism from ideation to contract signing.

...

"Pull mechanisms are policy tools that create incentives for private sector entities to invest in research and development (R&D) and bring solutions to market. Whereas “push” funding pays for inputs (e.g. research grants), “pull” funding pays for outputs and outcomes (i.e. prizes and milestone contracts). These mechanisms “pull” innovation by creating a demand for a specific product or service, which drives private sector investment and efforts towards developing and delivering that product or technological solution.

"One example of a pull mechanism is an Advance Market Commitment (AMC), which is a type of contract where a buyer, such as a government or philanthropic organization, commits to purchasing (or subsidizing) a product or service at a certain price and quantity once it becomes available. This commitment creates a market for the product or service, providing a financial incentive for innovators to invest in R&D and develop solutions to meet that demand.

"An AMC was used in the early 2000s in the case of developing a pneumococcal vaccine for the strain of the virus affecting children in low and middle income countries. Another current example is Frontier, led by Stripe, which is an AMC to accelerate carbon removal.

"In general, pull mechanisms are useful when we know we need an innovation, but we don’t who is best placed to develop it or how."

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

Earlier:

Friday, May 12, 2023


Thursday, June 22, 2023

Leo Hurwicz (1917-2008), biography

 Here's a web site devoted to the biography of Leo Hurwicz, by his son Michael: Leonid Hurwicz: Intelligent Designer

Wednesday, June 14, 2023

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

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

Here is the program.

Plenary Sessions



June 15th, 19:00 Murat Sertel Lecture

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

Chair: Salvador Barberà

June 16th, 17:00 Paul Kleindorfer Lecture

Alex Teytelboym: Duality in Market Design

Chair: Tommy Andersson

June 17th, 12:15 Leonid Hurwicz Lecture

Gabrielle Demange: Dual activities in a social network

Chair: Szilvia Pápai

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

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

Chair: Remzi Sanver

Introduction: Ayça Ebru Giritligil


Friday, May 12, 2023

Market Shaping at the University of Chicago: Promoting needed innovation

 One of many exciting talks yesterday at the first day of the New Directions in Market Design conference was by U. Chicago's Rachel Glennerster who announced the new market design initiative at U. Chicago:

Introducing the University of Chicago's Market Shaping Accelerator. Designing market shaping mechanisms to spur innovation to help solve some of the biggest global challenges.

"Accelerating Innovation

"Threats to the global community — such as climate change and pandemics — demand urgent innovation and action at scale. But when commercial incentives for innovation trail behind the social value, market shaping instruments are required to credibly signal demand and spur and scale up innovation.

"The Market Shaping Accelerator aims to harness the momentum and interest in these tools generated from global successes in vaccine development to accelerate their adoption by governments, multilateral institutions, and philanthropies to solve the world’s most pressing challenges.

"Nobel Laureates, Leading Scholars and Innovators Advance the Use of Market Shaping Instruments to Address Global Challenges​

"The Market Shaping Accelerator brings together the world’s leading market shaping experts. The team behind the Accelerator has contributed to both foundational research and prominent policy successes of market shaping mechanisms, including the Pneumococcal and Frontier Advanced Market Commitments (AMCs)."


Rachel Glennerster speaking about market shaping


Wednesday, May 10, 2023

New Directions in Market Design, NBER conference May 11-12, 2023 in Washington DC (and on YouTube)

 I'm on my way to this conference, celebrating a quarter of a century of practical market design by economists.

New Directions in Market Design, NBER conference May 11-12, 2023 (US Eastern Time)

LOCATION Convene, 600 14th St NW in Washington, DC. and livestreamed on YouTube 

ORGANIZERS Irene Y. Lo, Michael Ostrovsky, and Parag A. Pathak

 NBER conferences are by invitation. All participants are expected to comply with the NBER's Conference Code of Conduct.

Supported by Schmidt Futures

 Thursday, May 11

8:30 am Continental Breakfast

9:00 am Opening Talk: Alvin Roth, Stanford University and NBER ("Market Design and Maintenance") 

9:30 am Break

9:45 am Electricity and Renewable Energy Market Design

Overview: Mar Reguant, Northwestern University and NBER

Viewpoint 1: Martin Bichler, Technical University of Munich

Viewpoint 2: Richard O’Neill, Federal Energy Regulatory Commission

11:05 am Market Design for the Environment

Overview: Estelle Cantillon, ULB

Viewpoint 1: Rachel Glennerster, University of Chicago and NBER

Viewpoint 2: Nathan Keohane, Environmental Defense Fund

12:25 pm Lunch discussions

2:00 pm Market Design in Healthcare

Overview: Benjamin Handel, University of California at Berkeley and NBER

Viewpoint 1: Mark Miller, Arnold Ventures

Viewpoint 2: Fanyin Zheng, Columbia University

3:20 pm Market Design for Organ Transplantation

Overview: Tayfun Sonmez, Boston College

Viewpoint 1: Nikhil Agarwal, Massachusetts Institute of Technology and NBER

Viewpoint 2: Jennifer Erickson, Organize

4:40 pm Break

5:00 pm Market Design for Education

Overview: Parag Pathak, Massachusetts Institute of Technology and NBER

Viewpoint 1: Derek Neal, University of Chicago and NBER

Viewpoint 2: Irene Lo, Stanford University

6:20 pm Adjourn

6:45 pm Group Dinner - JW Marriott

Friday, May 12

8:00 am Continental Breakfast

8:30 am Market Design for Public Housing

Overview: Nathan Hendren, Harvard University and NBER

Viewpoint 1: Winnie van Dijk, Harvard University and NBER

Viewpoint 2: Mary Cunningham, Urban Institute

9:50 am Market Design in Transportation

Overview: Michael Ostrovsky, Stanford University and NBER

Viewpoint 1: David Shmoys, Cornell University

Viewpoint 2: Wai Yan Leong, Singapore Land Transport Authority

11:10 am Break

11:30 am Market Design in Financial Markets

Overview: Haoxiang Zhu, Massachusetts Institute of Technology and NBER

Viewpoint 1: Eric Budish, University of Chicago and NBER

Viewpoint 2: Scott Mixon, CFTC

12:50 pm

Lunch discussions

2:20 pm Market Design Tools in the Regulation of Online Marketplaces

Overview: Susan Athey, Stanford University and NBER

Viewpoint 1: Preston McAfee, Google

Viewpoint 2: Michael Schwarz, Microsoft

3:40 pm Artificial Intelligence and Market Design

Overview: Kevin Leyton-Brown, University of British Columbia

Viewpoint 1: Hal Varian, Google

Viewpoint 2: Nikhil Devanur, Amazon

5:00 pm Break

5:20 pm Closing Talk: Paul Milgrom, Stanford University

5:50 pm Adjourn

6:30 pm Group Dinner - JW Marriott

Wednesday, May 3, 2023

Market Design at the Max Planck Institute: Axel Ockenfels will become a Director, of ‘Economic Design & Behavior’

 Here's the announcement from the Max Planck Institutes:

Axel Ockenfels Appointed New Director at the Max Planck Institute for Research on Collective Goods in Bonn

"University of Cologne economist and expert in market design will establish the research department ‘Economic Design & Behavior’ at the MPI in addition to his work at the University of Cologne

"Axel Ockenfels, professor at the University of Cologne, will become a new director at the Max Planck Institute for Research on Collective Goods in Bonn in August 2023. He will establish a new department there, to be called ‘Economic Design & Behavior’. Its aim will be to design market, incentive, and decision architectures, based on modern behavioral research. Professor Dr. Ockenfels will thus complement the departments of Professor Dr. Matthias Sutter and Professor Dr. Christoph Engel at the institute, which focus on behavioral research from an economic and legal perspective. He will continue to teach and conduct research at the University of Cologne.

"As a faculty member of the University of Cologne, Professor Ockenfels heads the Cologne Laboratory for Economic Research and coordinates both the ‘Center for Social and Economic Behavior’ and the research division ‘Market Design & Behavior’ of the Cologne-Bonn Cluster of Excellence, ECONtribute. His appointment to the MPI in Bonn will further intensify the cooperation between the Faculty of Management, Economics and Social Sciences at the University of Cologne and the MPI in Bonn, a cooperation that has already contributed to the creation of a prestigious research center for economic behavior and design research in recent years.

...

"The new department at the Bonn MPI will also investigate ethical aspects of institutions and behavior as well as the opportunities and risks of modern computer technology for new markets. Most recently, Ockenfels has contributed to crisis management, for example with proposals for a market design to secure the supply of vaccines, to avoid supply disruptions in the energy sector, and to reduce energy consumption.

...

"Brief CV Axel Ockenfels

"Axel Ockenfels studied economics at the University of Bonn until 1994. He received his doctorate and habilitation from the University of Magdeburg, with periods abroad at Penn State University and Harvard University. Subsequently, he was Emmy-Noether Junior Research Group Leader at the Max Planck Institute for Economics in Jena. In 2003, he became Professor of Economics at the University of Cologne. Research periods have taken him to Stanford University and, currently, to the University of California in San Diego, among other places.

"In 2005, Ockenfels became the first economist in 17 years to be awarded the Gottfried Wilhelm Leibniz Prize of the German Research Foundation (DFG). He is a member of the National Academy of Sciences Leopoldina, the Berlin-Brandenburg Academy of Sciences and Humanities, the North Rhine-Westphalian Academy of Sciences and Arts, and the National Academy of Science and Engineering (acatech). He also sits at the Economists’ Round Table in the Federal Chancellery and on the Scientific Advisory Board at the Federal Ministry of Economics and Climate Protection (BMWK)."

Tuesday, April 11, 2023

Experiments and market design, video (I'm interviewed by Chiara Spina from INSEAD)

Professor Chiara Spina interviewed me about the use of experiments in market design (20 minute video). (We spoke about a number of experiments I collaborated on with Judd Kessler, among others.)


Thursday, April 6, 2023

Introductory workshops to the Mathematics and Computer Science of Market and Mechanism Design semester at Berkeley MSRI

 The semester of Mathematics and Computer Science of Market and Mechanism Design August 21, 2023 to December 20, 2023 at Berkeley will lead off with two introductory sessions:

Connections Workshop: Mathematics and Computer Science of Market and Mechanism Design  September 07, 2023 - September 08, 2023

REGISTRATION DEADLINE: AUGUST 18, 2023

TO APPLY FOR FUNDING YOU MUST REGISTER BY: MAY 17, 2023

Organizers Michal Feldman (Tel-Aviv University), LEAD Nicole Immorlica (Microsoft Research)

"The Connections Workshop will consist of invited talks from leading researchers at all career stages in the field of market design.  Particular attention will be paid to real-world applications.  There will also be an AMA focused on career paths with highly visible individuals in the field, and a social event intended to help workshop attendees network with each other."

and

Introductory Workshop: Mathematics and Computer Science of Market and Mechanism Design  September 11, 2023 - September 15, 2023

REGISTRATION DEADLINE: AUGUST 25, 2023  TO APPLY FOR FUNDING YOU MUST REGISTER BY: MAY 21, 2023  

Organizers Scott Kominers (Harvard Business School), Paul Milgrom (Stanford University), Alvin Roth (Stanford University), Eva Tardos (Cornell University)

"The workshop  will  open  with  overview/perspective  talks  on  algorithmic  game  theory  and  the theory and practice of market design; the afternoon will feature a panel on active research areas in the field (again, at the overview level). The next 2 days will consist of introductory mini-course and tutorials, on topics such as game theory, matching, auctions, and mechanism design. The following day will focus on applicable tools and technology, such as lattice theory, limit methods, continuous optimization, and extremal graph theory. The workshop will conclude with a panel discussion on major open problems."


Earlier announcement:

Tuesday, November 8, 2022

Tuesday, February 28, 2023

Democracy & “Noxious” Markets, by Debra Satz

 The Winter 2023 issue of Daedalus is about Creating a New Moral Political Economy, edited by Margaret Levi & Henry Farrell.

The article by Debra Satz will strike a chord with market designers: she takes very seriously that markets are tools that need thoughtful design.

"my argument is not a lawyer’s brief against markets. No large democratic society can or should entirely dispense with markets. Not only are markets among the most powerful tools we have for generating growth in living standards and incentivizing innovation, but also Smith was right to see their democratic potential as ways of enabling cooperation among independent, free, and equal individuals. As tools, however, we should think carefully about where to use them and how to design them when we do. While a neoliberal worldview sees efficient markets enhancing freedom and well-being everywhere, the reality is more complex. Some markets foreclose options that would better support democratic institutions and culture. Sometimes, closing off market options makes everyone better off. Consider that if individuals are free not to purchase health insurance on the market, the cost of publicly provided insurance will increase: healthy individuals are more likely to opt out of health insurance, leaving sicker individuals in the pool to be insured and raising the costs of their insurance, leading more people to forgo holding such insurance, driving the prices up even higher."


Among the markets she is concerned about are school choice, and military service:

"some of the ways parents prioritize their own children can lead to worse outcomes for other children and to the furthering of educational inequities, as well as to other social ills like instability and conflict. Evidence indicates, for example, that choice schools in the United States are more homogenous than public schools with respect to social class and race. Researchers have also shown that when public school choice is available, educated parents are especially likely to factor child demographics in their school selections.11 This may be because school quality is very hard to judge and parents default to markers such as the reading and math levels of other students. These levels, in turn, are heavily influenced by social class. It is likely that some parents take race and class directly as proxies for school quality."

...

"Extending the reach of markets even more, war has been further outsourced to private military contractors: in 2009, there were more private military contractors in Afghanistan than U.S. military troops.17 Hiring private mercenaries and outsourcing national security to a subsection of our population might spare our citizens, but as political philosopher Michael Sandel has noted, it changes the meaning of citizenship.18 In what sense are we “all in this together” if most citizens never need to think hard about decisions to go to war? Whatever the efficiency pros and cons of the decision to outsource fighting and allocate military service through market means, doing so changes our relationships with one another and our sense of a common life."

"My argument so far suffers from treating the state and market as two stark alternatives for the allocation of goods and services in society. So I now want to consider ways in which the benefits of markets can be harnessed—through design—to better serve important democratic goals. "

...

"One important mechanism is providing greater roles for worker voice. This can be done through such reforms as changing labor laws to support forms of worker association, like trade unions, allowing worker representatives on company boards, and strengthening democracy at work through diverse forms of ownership including worker-managed and -owned firms. Empowering the associational organization of labor would also help redress the background social conditions that render workers vulnerable to the oligarchic power of their employers.

"There are other examples in which careful design and policy can limit the “noxiousness” of a particular market for democracy. Policies such as a negative income tax can strengthen the power of workers, and campaign finance laws can diminish the power of money in elections. Others have argued for reforms to our current system of commodified legal representation within an adversarial system, and for single-payer health care systems."

Here's her concluding paragraph:

"Beyond education, we need to pay special attention to particular markets that affect democratic functioning and stability. Such markets include but are not limited to markets in legal representation, media and news markets, markets relating to national defense, and markets governing political rights. Politicians and other commentators usually write unreflectively, as if all markets were the same. They are not. Markets affect not only the distribution of income and wealth, but also our capacities, and our views of each other. Their strengths but also their limits depend on the fact that they are radically individualizing. But in some contexts, that individualizing threatens the practice of democracy. Markets have moral and even “spiritual” consequences relevant to our shared public life, and our evaluations of them must also attend to those consequences. A new political economy needs to take this larger evaluative frame into account."

******

The next article in the issue is a thoughtful essay on markets for personal care of the young and the elderly, organized in various ways, including care within families, written as a commentary on the Satz article: 

Is There a Proper Scope for Markets?  by Marc Fleurbaey

Friday, January 13, 2023

Affirmative action in India--a market design perspective, by Ashutosh Thakur, Orhan Aygün, Bertan Turhan, and M. Bumin Yenmez

 The policy portal Ideas for India has an e-symposium on recent developments in affirmative action in India, with an informative introduction by Parikshit Ghosh, and short papers by Ashutosh Thakur, and by Orhan Aygün, Bertan Turhan,  and M. Bumin Yenmez. It's encouraging to see that the attention to these issues by such serious market designers is getting prompt exposure to policy makers in India.

Here's the introduction (which I've copied in it's entirety, with links):

Introduction to e-Symposium: The architecture of affirmative action 12 December, 2022 by Parikshit Ghosh

The Supreme Court of India recently upheld an amendment that excluded Scheduled Castes, Scheduled Tribes and Other Backwards Classes from the Economically Weaker Section (EWS) quota, restricting it only to general category applicants. However, the specifics of how this reservation policy is executed can have important social and political implications. 

Across this week, from 12-16 December, this I4I e-Symposium brings together articles that provide a theoretical basis – using principles of market design, and search and matching theory – for more efficient implementation of reservation policies. Anchored by I4I’s Editor-in-Chief Parikshit Ghosh, the e-Symposium aims to open a discussion on the architecture of affirmative action, from the mechanisms of vertical and horizontal reservations, to ensuring efficiency in meeting diversity targets.

The authors of the Indian Constitution had the wisdom to see that our tryst with destiny will be unfulfilled if we do not confront the ghosts from our past. Even as Articles 14 and 15 pronounced equal treatment for all, Article 15(4) paved the way for reservations targetted at socially disadvantaged groups. The founders of the Indian republic understood that a newly independent nation had a historic opportunity to not only break the shackles of colonialism, but also oppression in all its forms. A narrow, ahistorical notion of meritocracy did not suit this mandate. 

Still, after more than seven decades of experience, questions swirl around our reservation policy. Who deserves protection? When should it be withdrawn? Is social disadvantage synonymous with economic deprivation? Grappling with these difficult issues requires not only input from the social sciences, but also an engagement with ethics and politics. Unlike the design of airports or the sale of spectrum, this is an area where the public interest cannot entirely be left to academics and bureaucrats. 

However, affirmative action does not involve only the setting of diversity targets – which is fundamentally an expression of democratic will – but also calls for the design of concrete institutional rules to achieve these targets with the least sacrifice of the meritocratic ideal. Should general category seats be filled before the SC/ST seats or vice versa? If an OBC candidate with disability is recruited, should it count towards fulfilling both the OBC and disability quotas, or just one of them? How exactly these finer points are settled can be profoundly consequential, as economists have learnt from several decades of research on market design (Roth 2007)

While affirmative action targets have been well articulated by legislatures, the rules for implementing them have been left ill specified, requiring courts to step in time and again. Many landmark judgments of the Supreme Court are attempts to reduce the confusion and conflict arising from procedural ambiguity. 

Unfortunately, this design aspect of reservation policy, what I call the architecture of affirmative action, has not only received scant attention in the media and public debate, but its importance seems to go largely unrecognised. Our aim with this e-Symposium is to start that conversation. 

In Indra Sawhney vs. Union of India (1992), the Supreme Court mandated the earmarking of certain positions for caste-based categories (like SCs, STs and OBCs) – what has come to be known as vertical reservation – but left the fulfillment of diversity targets for other categories (such as persons with disabilities) more flexible – an arrangement referred to as horizontal reservation. In the opening article of this symposium, Ashutosh Thakur revisits this issue and provides a critique of vertical reservations. Among other things, it has no built-in sunset clause and requires legislatures to continuously revise quotas as disadvantaged groups economically catch up with others. 

The next two articles come from researchers who have studied how to devise efficient ways of meeting diversity goals, as well as matching two sides of a market (for example, assigning students to schools or colleges) in a sensible way. In the second article of the series (their first), Orhan Aygun, Bertan Turhan and Bumin Yenmez point out that though the five judge bench upheld restricting the Economically Weaker Section (EWS) quota to general category applicants, SC/ST/OBC candidates could still make themselves eligible for these positions by not declaring their caste identity, and explore the implications of such a loophole. 

The final article examines the process through which rank holders from the joint entrance examination (JEE) are assigned to the various Indian Institutes of Technology (IITs) and other technical colleges. The assignment must respect student merit ranks, their stated preference over institutions and programmes, and the quota requirements within each institution. In addition to that, the judgment in Ashok Kumar Thakur vs Union of India (2008) stipulates that unfilled OBC quota seats (but not SC/ST quotas) should be made available to general category applicants to reduce wastage. This is clearly a complex task.   

The system currently in place was designed by the government, in consultation with a group of computer scientists and market designers (Baswana et al. 2019). It is based on the celebrated Gale-Shapley algorithm1 and tries to ensure that within the constraints of the diversity requirement, the allocation is fair and efficient. Many readers may be unaware that a rare confluence of legislative will, judicial oversight and technocratic finesse has designed the staircase to success so many Indians aspire to step on. Yet, as Aygun, Turhan and Yenmez point out through simple and illuminating examples, when it comes to de-reserving unfilled OBC seats, the current system has subtle flaws that can and ought to be corrected. 

After 75 years of Independence, we can take some pride in our quest for an affluent and just society, yet be vigilant about the gaps in that attempt and strive to bridge them. 

Design choices for implementing affirmative action

Ashutosh Thakur

Ashutosh Thakur explains the various ways in which affirmative action policies can be implemented, and discusses the underlying trade-offs and issues at hand...

Challenges of executing EWS reservation efficiently

Orhan Aygün, Bertan Turhan, M. Bumin Yenmez

Aygün, Turhan, and Yenmez look at the implications of reserved category members having to choose between applying for positions on the basis of their caste or income...

Improving admissions to technical colleges in India

Orhan Aygün, Bertan Turhan, M. Bumin Yenmez

Aygün, Turhan, and Yenmez examines the process through which JEE rank holders are assigned to the various IITs and other technical colleges...

Note: 

  1. The Gale–Shapley algorithm is an algorithm used for finding a solution to the stable matching problem, and has been described as solving both the college admission problem and the stable marriage problem.




Further Reading