Friday, July 26, 2013

School choice in New Orleans

The one-application system in New Orleans is suffering from some growing pains, as it faces the demands of charter schools and others. One difficult question that faces all school districts is how to deal with the non-negligible number of "no-shows" as the school year starts, and the places they may free up in desirable schools that were over capacity. In New Orleans, they have tried to move the date forward by requiring confirmation of plans to attend before the beginning of the school year.

In choice system, New Orleans schools face new problems with no-shows (July 13)

Of course, sometimes the problem is not as big as anticipated

Fewer than 30 students lose seats at Orleans Parish conventional schools (July 16)

Thursday, July 25, 2013

Yemeni girl's speech against child marriage goes viral

Al Jazeera has the story, and the moving video, with an 11 year old girl speaking out against child marriage: Yemeni girl's speech against child marriage goes viral

Wednesday, July 24, 2013

The market for integers: Edelman and Schwarz on IP addresses


Pricing and Efficiency in the Market for IP Addresses
Benjamin Edelman , Harvard Business School and Michael Schwarz, Google
June 9, 2013
Abstract
We consider market rules for the transfer of IP addresses, numeric identi fiers required by all  computers connected to the Internet. Excessive fragmentation of IP address blocks causes growth in the Internet's routing table, which is socially costly, so an IP address market should discourage subdividing IP address blocks more than necessary. Yet IP address transfer rules also need to facilitate purchase by the networks that need the addresses most, from the networks that value them least. We propose a market rule that avoids excessive fragmentation while almost achieving social efficiency, and we argue that implementation of this rule is feasible despite the limited powers of central authorities. We also off er a framework for the price trajectory of IP addresses. In a world without uncertainty, the unit price of IP addresses is constant until all addresses are in use and begins to decrease at that time. With uncertainty, the price before that time is a martingale, and the price trajectory afterwards is a supermartingale. Finally, we explore the role of rental markets in sharing information about address value and assuring allocative efficiency

Tuesday, July 23, 2013

Kidney exchange chain in India

Kidney exchange makes some progress in India: the story is here.

HT: Seema Arora


Monday, July 22, 2013

Ron Paul on paying organ donors

Ron Paul: End government control of organ transplants and compensate donors

"In his weekly Texas Straight Talk column — which has continued after his departure from Congress in January — Paul called for a repeal of he federal ban on compensating organ donors. Calling the support of the current system nonsensical, Paul asked, “If we trust the market to deliver food, shelter, and all other necessities, why should we not trust it to deliver health care- including organs?”"

Here's his column in full:


***Please note: This is the temporary home for my weekly column until my personal web page is up and running.***

Let Market Forces Solve Organ Transplant Crisis


Ten-year old cystic fibrosis patient Sarah Murnaghan captured the nation’s attention when federal bureaucrats imposed a de facto death sentence on her by refusing to modify the rules governing organ transplants. The rules in question forbid children under 12 from receiving transplants of adult organs. Even though Sarah’s own physician said she was an excellent candidate to receive an adult organ transplant, government officials refused to even consider modifying their rules.
Fortunately, a federal judge intervened so Sarah received the lung transplant. But the welcome decision in this case does not change the need to end government control of organ donations and repeal the federal ban on compensating organ donors.
Supporters of the current system claim that organ donation is too important to be left to the marketplace. But this is nonsensical: if we trust the market to deliver food, shelter, and all other necessities, why should we not trust it to deliver healthcare—including organs?
It is also argued that it is “uncompassionate” or “immoral” to allow patients or insurance companies to provide compensation to donors. But one of the reasons the waiting lists for transplants is so long, with many Americans dying before receiving a transplant, is because of a shortage of organs. If organ donors, or their heirs, were compensated for donating, more people would have an incentive to become organ donors.
Those who oppose allowing patients to purchase organs should ask themselves how compassionate is it to allow those people to die on the transplant waiting list who might otherwise have lived if they were able to obtain organs though private contracts.
Some are concerned that if organ donations were supplied via the market instead of through government regulation, those with lower incomes would be effectively denied access to donated organs. This ignores our current two-tier system for allocating organs, as the wealthy can travel overseas for transplants if they cannot receive a transplant in America. Allowing the free market to alleviate the shortage of organs and reduce the costs of medial procedures like transplants would benefit the middle class and the poor, not the wealthy.
The costs of obtaining organs would likely be covered by most health insurance plans, thus reducing the costs directly borne by individual patients. Furthermore, if current federal laws distorting the health care market are repealed, procedures such as transplants would be much more affordable. Expanded access to health savings accounts and flexible savings accounts, combined with generous individual tax deductions and credits, would also make it easier for people to afford health care procedures such as transplants.
There is also some hypocrisy in the argument against allowing market forces in organ transplants. Everyone else involved in organ transplantation procedures, including doctors, nurses, and even the hospital janitor, receives compensation. Not even the most extreme proponent of government-provided health care advocates forcing medical professionals to provide care without compensation. Hospitals and other private institutions provide compensation for blood and plasma donations, and men and women are compensated for donations to fertility clinics, so why not allow compensation for organ donation?
Sarah Murnaghan’s case shows the fallacy in thinking that a free-market system for organ donations is less moral or less effective than a government-controlled system. It is only the bureaucrats who put adherence to arbitrary rules ahead of the life of a ten-year old child. It is time for Congress to wake up and see that markets work better in all aspects of health care, including organ donation, just as they work better in providing all other goods and services.
Permission to reprint in whole or in part is gladly granted, provided full credit is given.

Sunday, July 21, 2013

SITE workship on Dynamic Games, Contracts and Markets, July 29-31 2013

The announcement is here:

Stanford Institute for Theoretical Economics
Summer 2013 Workshop

Segment 4: Dynamic Games, Contracts, and Markets
July 29, 30 and 31, 2013
Organized by Yuliy Sannikov, Princeton University; Simon Board, University of California, Los Angeles; Andrzej Skrzypacz, Graduate School of Business, Stanford University and Alexander Wolitzky, Pablo Kurlat, Florian Scheuer, all Department of Economics, Stanford University.
This Segment of SITE is partially sponsored by The Graduate School of Business, Stanford University.


Monday, July 29, 2013
8.30 - 9.00 Breakfast
*Part 1: Agency with Frequent Actions
9.00 - 9.45 Yuliy Sannikov, Princeton University: Moral Hazard and Long-Run Incentives
9.45 - 10.15 Coffee
10.15 - 11.00 Tomasz Sadzik, University of California, Los Angeles and Ennio Stacchetti, New York University: Agency Models with Frequent Actions: A Quadratic Approximation Approach
11.00 - 11.30 Coffee
11.30 - 12.15 George Georgiadis, California Institute of Technology and Boston University: Projects and Team Dynamics
12.15 - 2.00 Lunchtime discussion
*Part 2: Dynamic Agency
2.00 - 2.45 Guy Arie, Rochester University: Dynamic Costs and Moral Hazard
2.45 - 3.15 Coffee
3.15 - 4.00 Qingmin Liu, Marina Halac and Navin Kartik, all Columbia University: Optimal Contracts for Experimentation
4.00 - 4.30 Coffee
4.30 - 5.15 Mikhail Golosov, Princeton University and Luigi Ioviono, Toulous School of Economics:Social Insurance, Information Revelation, and Lack of Commitment

Tuesday, July 30, 2013
*Part 3: Dynamic Mechanism Design
8.30 - 9.00 Breakfast
9.00 - 9.45 Daniel Garrett, Toulouse School of Economics and Alessandro Pavan, Northwestern University: Dynamic Managerial Compensation: On the Optimality of Seniority-Based Schemes
9.45 - 10.15 Coffee
10.15 - 11.00 Andrzej Skrzypacz, Graduate School of Business, Stanford University and Juuso Toikka,Massachusetts Institute of Technology: Mechanisms for Dynamic Bargaining
11.00 - 11.30 Coffee
11.30 - 12.15 Jeffrey Ely, Northwestern University, Alex Frankel and Emir Kamenica, both University of Chicago, Booth School of Business: Suspense and Surprise
12.15 - 2.00 Lunchtime discussion
*Part 4: Repeated Games
2.00 - 2.45 Axel Anderson, Georgetown University and Lones Smith, University of Wisconsin, Madison: Dynamic Deception
2.45 - 3.15 Coffee
3.15 - 4.00 Takuo Sugaya, Graduate School of Business, Stanford University: Efficiency in Markov Games with Incomplete and Private Information
4.00 - 4.30 Coffee
4.30 - 5.15 David Rahman, University of Minnesota: Frequent Actions with Infrequent Coordination
6.30 Continued discussion and dissemination of technical knowledge during dinner

Wednesday, July 31, 2013
*Part 5: Search/Experimentation/Information Aggregation in Markets
8.30 - 9.00 Breakfast
9.00 - 9.45 Yoon Koo Che, Colombia University and Johannes Horner, Yale University: Optimal Design for Social Learning
9.45 - 10.15 Coffee
10.15 - 11.00 Stephan Lauermann, University of Michigan and Asher Wolinsky, Northwestern University: Search with Adverse Selection
11.00 - 11.30 Coffee
11.30 - 12.15 Marzena Rostek, University of Wisconsin, Madison and Semyon Malamud, EPF Lausanne: Dynamic Thin Markets
12.15 - 2.00 Lunchtime discussion
*Part 6: Reputation and Sequential Screening
2.00 - 2.45 Bruno Strulovici, Northwestern University: Coase Conjecture and Efficiency: A Foundation for Renegotiation-proof Contracts
2.45 - 3.15 Coffee
3.15 - 4.00 Dilip Abreu, Princeton University, and David Pearce and Ennio Stacchetti, both New York University: One-Sided Uncertainty and Delay in Reputational Bargaining
4.00 - 4.30 Coffee
4.30 - 5.15 Juan Pablo Xandri, Princeton University: Credible Reforms: A Robust Implementation Approach

Saturday, July 20, 2013

Monty Python's take on organ donation

Not for the faint of heart, here is Monty Python's take on becoming registered as a deceased donor...

And here (for the humor impaired) is the Mythbusters review of that clip: “Hello, Can We Have Your Liver?” and the Damage of the Monty Python Sketch, excerpted below

"In the scene in question a knock comes at a man’s door.  “Hello, can we have your liver?” asks John Cleese, clad in a white coat on the doorstep, “But, I’m (still) using it!!!” objects the resident.  His wife comes along as Cleese and company are ripping the liver from her screaming husband, “is this because he took out one of those silly cards?,” she asks, and then adds,  “Typical of him! Always full of good intentions!”

"While art –in this case comedy– can turn our eyes inwards, scenes like this,  urban legends, and other myths have done much to discourage organ donation in our society.  At the crux of the matter is the fact that organ donation can save lives. Many lives. When you pass away your thoughtfulness and selflessness can give someone back a life they might otherwise not live.

"Here is that myth debunked.

"THE MYTH: If I sign my donor card or register my consent & I become injured or sick, the Doctors will not take every care to keep me alive. Instead they will let me die with an eye towards harvesting my organs.

"MYTH BUSTED: The registry can’t be accessed until a person is declared dead. Also, ICU doctors are a different bunch than the Transplant Docs. You need two independent docs trained in the diagnosis of brain death to proceed to donation. No two docs, no donation.

"There’s a bunch of other protections as well. The key thing is, if this myth happened even once, donor rates would collapse, the system requires total confidence."

Friday, July 19, 2013

Medicare's 3 year limit on post-transplant immunosuppressive drugs

A lot has been written about this, here's yet another story that puts a personal edge on a systematic problem and a big waste of taxpayer dollars through a false economy: Medicare disserves younger kidney-transplant patients by DR. JANANI RANGASWAMI, FOR THE INQUIRER

Thursday, July 18, 2013

Market design talk at Sun Yat Sen University in Guangzhou

Here's an ex-post account, from which the picture below is taken. (I earlier posted a link to a pre-talk account.) One of the people I met there, Professor Pu Yongjian, of the School of Economics and Business Administration at Chongqing University, gave me his book in Chinese on matching and related topics. I think matching and market design more generally could prove useful in China.

Unraveling in the market for chefs?

It turns out that good restaurants need good cooks, and they are hard to find and keep in the growing market for fancy restaurants: Talent Shortage: Why New York’s Chefs Can’t Find Enough Good Cooks

Stephanie Hurder points out to me that the article hints at possible unraveling of the market:

"Another move is judging final exams at culinary schools like the International Culinary Center. If a chef sees a student whose work impresses them, they can offer the student a trailing gig — like an extended interview in the kitchen — on the spot."


Wednesday, July 17, 2013

Prize in Game Theory and Computer Science to Edelman, Ostrovsky and Schwarz, and Varian

Here's the prize announcement:

Prize in Game Theory and Computer Science of the Game Theory Society

in Honour of Ehud Kalai, endowed by Yoav Shoham

Following the Call for Nominations, the 2013 Prize is awarded in equal parts to Benjamin Edelman, Michael Ostrovsky, Michael Schwarz, and Hal R. Varian for their papers
Benjamin Edelman, Michael Ostrovsky, and Michael Schwarz, "Internet Advertising and the Generalized Second-Price Auction: Selling Billions of Dollars Worth of Keywords," American Economic Review 97, pages 242-259, 2007,
and
Hal R. Varian, "Position Auctions," International Journal of Industrial Organization 25, pages 1163-1178, 2007,
for their fundamental analysis of Online Advertisement Auctions.
The Prize committee, appointed by Roger Myerson as President of the Game Theory Society, consisted in 2013 of Paul W. Goldberg, Kevin Leyton-Brown, Éva Tardos, and Bernhard von Stengel.
In their report to the President, they stated their reasons for selecting this work as follows, referring to the papers as "EOS" and "Varian":
A very significant body of research at the interface of game theory and computer science concerns the design of automated mechanisms for economic transactions, which typically take place on the internet. A prime example are advertisements that search engines such as Google, Bing or Yahoo! place next to the results of internet searches for a given keyword. When a user clicks on such an ad, the search engine receives money from the advertiser. The payment is determined by an auction mechanism that computes the available advertisement "slots" to the bids which are dynamically provided by the bidders for each keyword search.
EOS and Varian (independently) analyzed an auction format known as the "generalized second price auction", a term coined by EOS, which is now used by the major search engines. Their work is of unparalleled theoretical and practical influence. At the time of this writing, it has attracted over 1,400 combined citations (about 800 for EOS and 600 for Varian) and the two articles are by far the most influential papers in the area.
The design of market mechanisms that are implemented algorithmically represents a most fruitful interaction of game theory and computer science. The work of EOS and Varian has spawned research - and, also significantly, attractive jobs for economic and computing theorists - to an extent that they clearly deserve the Prize.
Congratulations to the winners! They will present their work at the occasion of the award on July 17, 2013, at the Workshop on Computational Game Theory in Stony Brook, New York.

Call for nominations - Prize in Game Theory and Computer Science

(mailed to GTS members by Roger Myerson on 25 April 2013)
The Prize in Game Theory and Computer Science of the Game Theory Society was established in 2008 by a donation from Yoav Shoham in recognition of Ehud Kalai's role in promoting the connection of the two research areas. The last time the Prize was awarded at the Third World Congress of the Society in 2008 in Evanston. This time, the Prize will in 2013 be awarded at the Workshop on Computational Game Theory in Stony Brook, New York (July 16-18, 2013).
The Prize will be awarded to the person (or persons) who have published the best paper at the interface of game theory and computer science in the last decade. Preference will be given to candidates of age 45 or less at the time of the award, but this is not an absolute constraint. The amount of the Prize will be USD 2,500 plus travel expenses of up to USD 2,500 to attend the scientific event where the Prize is awarded.
The Game Theory Society invites nominations for the Prize. Each nomination should include a full copy of the paper (in pdf format) plus an extended abstract, not exceeding two pages, that explains the nature and importance of the contribution.
Nominations should be emailed to the Society's Secretary-Treasurer, Federico Valenciano (at federico.valenciano@ehu.es ) by 15 May 2013. The selection will be made by a committee appointed by the President, and the result will be announced in June 2013.

Tuesday, July 16, 2013

Egg donation in Israel at a new, higher price

Egg donors to be compensated with NIS 19,000

"The Knesset's Labor, Welfare and Health Committee approved raising compensation sum to egg donors to NIS 19,000 ($5200) due to lack of donors.

"Since the bill to allow women to donate eggs in Israel was approved over a year and a half ago, only seven women had donated eggs, and were given NIS 10,000 ($2800). The Health Ministry requested to raise the compensation total in order to increase the number of donors due to severe shortage of eggs."

Monday, July 15, 2013

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

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

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

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

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

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

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

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

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

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



Sunday, July 14, 2013

Future of Game Theory: Stony Brook roundtable

This past week I had the opportunity to listen to a discussion of "The Present and Future of Game Theory". The highlight was a set of short talks by Aumann, Fudenberg, Kalai, and Maskin:

Robert Aumann* (Hebrew University and Stony Brook University) Overview
Drew Fudenberg (Harvard University) Predictive Game Theory
Ehud Kalai (Northwestern University) Game Theory and Computer Science
Eric Maskin* (Harvard University)  The Present and Future of Mechanism Design

Bob Aumann opens the session on the present and future of game theory
To my pleased surprise, they all seemed to see the future of game theory in applications of various kinds.








 Bob Aumann's first examples, of "hard" (as opposed to "soft") applications were from market design


Drew Fudenberg speaks about predictive game theory














 Drew focused on "predictive game theory," and the need for experiments and computational models.










Ehud Kalai speaks about game theory and computer science





Ehud Kalai spoke without slides, in front of photos of Lloyd Shapley and Jean Francois Mertens, who were honored in different ways at the conference. He spoke about how game theory and computer science are likely to become increasingly entangled in the years to come.

Eric Maskin speaks about the future of mechanism design








Eric Maskin included the fall of the planned economies of Eastern Europe among the applications of mechanism design, and also included the design of auction and matching markets.













Later in the same session I spoke about some of the differences between "game engineering" and game theory, and elaborated on the following points that I think are typical of the situation we often find ourselves in in market design:
1. We don’t know the whole game
2. We can’t compare designs just by their equilibria
3. Design solutions can’t always wait for reliable scientific knowledge
4. Market design solutions don’t last forever
5. We can’t just do the game theory, other problems have to be addressed to have a complete design

Saturday, July 13, 2013

Market design conference at Lund, July 25-27

Here is the conference website: Conference on Economic Design 2013 (25-27 July)

Beforehand, The Arne Ryde Foundation will organize a two-day mini-course on Economic Design July 23-24, 2013. The course is directed towards PhD students and post-docs wanting a firm grounding in the subject and consists of four lectures on Economic Design given by leading researchers in the field (Gabrielle Demange, Bettina Klaus, Tayfun Sönmez and William Thomson).

The conference program is here.

The keynote addresses are

Murat Sertel Lecture, Date and time: July 25, 17:35-18:50
Chair: M. Utku Ünver(Department of Economics, Boston College)
Professor Tayfun Sönmez(Department of Economics, Boston College)
Kidney Exchange: Past, Present, and Potential Future

SED Lecture Date and time: July 26, 09:00-10:15
Chair: Lars Ehlers(Département de Sciences Économiques and CIREQ, Université de Montréal)
Professor William Thomson (University of Rochester, Department of Economics)
Allocation when Preferences are Single-peaked: Basic Model and New Directions

SED Lecture, Date and time: July 26, 17:20-18:35
Chair: Tommy Andersson (Department of Economics, Lund University)
Professor Paul Klemperer(Oxford University, Nuffield College)
Geometry, Auctions, and Matching


Friday, July 12, 2013

Tim Besley reviews "What Money Can't Buy" by Michael Sandel

Besley likes Sandel's book (while recognizing its flaws): Here's the opening sentence of his review in the Journal of Economic Literature(2013, 51(2), 478–495):

"Michael Sandel’s What Money Can’t Buy (WMCB hereafter) is a great book and I recommend every economist to read it even though we are not really his target audience."

I've written a bunch of blog posts about Sandel's views on markets, and others on repugnant transactions and markets, so I won't go into the details again here.

Let me instead give Besley the last word. Here are two paragraphs from his Final Remarks:

"The timing of WMCB may seem ironic in a year in which the Nobel Prize was awarded to Alvin Roth and Lloyd Shapley for their important work on market design that underpins a large expansion of exchange and matching into domains such as school choice, labor markets, and kidney exchange.
As Roth (2008) explains, the approach that he has taken is sensitive to issues of social constraints on market allocations. For example, he acknowledges that having a role for prices in kidney exchanges offends societal values. So the market design that has been proposed in this setting looks for exchanges that are feasible without prices. Thus, the concerns in WMCB are already taken on board by those who are actively promoting more socially sensitive forms of exchange.
...
"At the outset, WMCB identifies two obstacles to rethinking the role and reach of markets. One is the power and prestige of market thinking. The other is the rancor and emptiness of public discourse. Most economists will regard the first as well earned and many would gladly take a bow. But it seems hard to dispute that the need to participate in and engage with debates about markets (and governments) is a central obligation of the economics profession. WMCB is to be applauded for supplying both provocation and insight on a wide range of important topics. And it suggests
a range of challenges to which the discipline of economics can respond."


HT: Parag Pathak

Thursday, July 11, 2013

From auctions to buy-it-now on eBay

eBay has changed since I started studying in the late 1990's, when it was all auctions all the time.
Here's the story:

SALES MECHANISMS IN ONLINE MARKETS:
WHAT HAPPENED TO INTERNET AUCTIONS?
by Liran Einav
Chiara Farronato
Jonathan D. Levin
Neel Sundaresan
Working Paper 19021
http://www.nber.org/papers/w19021


ABSTRACT
Consumer auctions were very popular in the early days of internet commerce, but today online sellers mostly use posted prices. Data from eBay shows that compositional shifts in the items being sold, or the sellers offering these items, cannot account for this evolution. Instead, the returns to sellers using auctions have diminished. We develop a model to distinguish two hypotheses: a shift in buyer demand away from auctions, and general narrowing of seller margins that favors posted prices. Our estimates suggest that the former is more important. We also provide evidence on where auctions still are used, and on why some sellers may continue to use both auctions and posted prices.

Wednesday, July 10, 2013

a pre-emptive letter of rejection from one of my favorite journals, Games and Economic Behavior

Along with what I presume are very many other people, I recently received this email from the editors of Games and Economic Behavior (GEB). The first part of the email (reproduced below) reads a lot like the rejection letters I get, and says that only papers of very broad general interest can be accepted (and not papers that are of interest to only some readers..).  But in this case the letter is being sent to people before they submit a paper. (The second part of the email sensibly encourages editors and referees to reject things quickly, at least, and use early desk rejections, so that people will still be willing to submit to a journal that is likely to reject their paper...)

"Dear GEB colleagues,

"We are writing to update you on the state of the journal, remind you of GEB's objective, ask for your help, and thank you for your contributions.

"Journals that publish papers in game theory
Currently, there are six journals devoted entirely to publishing game theory papers:
1. Games and Economic Behavior, Elsevier
2. International Journal of Game Theory, Springer
3. International Game Theory Review, World Scientific
4. International Journal of Mathematics, Game Theory and Algebra, Nova Publishers
5. Journal of Game Theory, Scientific & Academic Publishing - Open Access (Peer Review) 
6. Games, MDPI - Open Access (Peer Review) 

"In addition, most economic theory journals publish game theory papers and there is a fast growing number of game theory papers published in computer science and operations research journals. For example, one of the four sections of Mathematics of Operations Research is devoted entirely to game theory and ACM Transactions on Economics and Computation is heavily concentrated on game theory. 

"The unique role of GEB
The stated goal of GEB is to "facilitate cross-fertilization between theories and applications of game theoretic reasoning." With the expansion of game theory into a variety of subjects beyond economics (computer science, operations research and management, biology, sociology, psychology, linguistics, philosophy), it is important to communicate and coordinate game-theoretic research across these fields. To be effective in this mission, it is important to restrict publications in GEB to papers that are of general game theoretic interest (in a broad sense) and not to publish papers that are of interest only to narrow groups, even if they are high quality. With the current rate of more than 700 new submissions a year, this means that GEB has to maintain a high rate of rejection. The current rate of rejection is approximately five out of six newly submitted papers."


Tuesday, July 9, 2013

2013 Best paper prize to Michael Ostrovsky and Michael Schwarz for AEJ: Micro, 2 (2), "Information Disclosure and Unraveling in Matching Markets,"

A Best Paper Prize for the matching market view of grade inflation:)

AEJ: Micro, 2 (2), "Information Disclosure and Unraveling in Matching Markets," Michael Ostrovsky and Michael Schwarz


Abstract

This paper explores information disclosure in matching markets. A school may suppress some information about students in order to improve their average job placement. We consider a setting with many schools, students, and jobs, and show that if early contracting is impossible, the same, "balanced" amount of information is disclosed in essentially all equilibria. When early contracting is allowed and information arrives gradually, if schools disclose the balanced amount of information, students and employers will not find it profitable to contract early. If they disclose more, some students and employers will prefer to sign contracts before all information is revealed. 

Monday, July 8, 2013

Matching with couples in large markets: Kojima, Pathak and Roth

Fuhito Kojima, Parag Pathak and I have a paper coming out that suggests a beginning of an answer to the empirical puzzle presented by the fact that the many annual labor matching markets with couples that use the Roth-Peranson algorithm overwhelmingly find stable matchings, even though in principle they might fail to exist.  In large markets with short preference lists and without too many couples, the answer seems to be related to the fact that there remain sufficiently many unfilled positions so that vacancy chains are more likely to end than to cycle.

Here's the paper:
Kojima, Fuhito, Parag A. Pathak, and Alvin E. Roth, “Matching with Couples: Stability and Incentives in Large Markets,” April 2010, revised April 2013, Quarterly Journal of Economics, forthcoming.

Abstract: Accommodating couples has been a longstanding issue in the design of centralized labor market clearinghouses for doctors and psychologists, because couples view pairs of jobs as complements. A stable matching may not exist when couples are present. This paper's main result is that a stable matching exists when there are relatively few couples and preference lists are sufficiently short relative to market size. We also discuss incentives in markets with couples. We relate these theoretical results to the job market for psychologists, in which stable matchings exist for all years of the data, despite the presence of couples.