Gonzalo Arrieta defends his dissertation

Gonzalo Arrieta defended his dissertation last week.

Here's his job market paper:

Procedural Decision-Making In The Face OfComplexity by Gonzalo Arrieta and Kirby Nielsen

Abstract: A large body of work documents that complexity affects individuals’ choices, but the literature has remained mostly agnostic about why. We provide direct evidence that individuals use different choice processes for complex and simple decisions. We hypothesize that individuals resort to “procedures”—cognitively simpler choice processes that we characterize as being easier to describe to another person—as the complexity of the decision environment increases. We test our hypothesis using two experiments, one with choices over lotteries and one with choices over charities. We exogenously vary the complexity of the decision environment and measure the describability of choice processes by how well another individual can replicate the decision-maker’s choices given the decision-maker’s description of how they chose. We find strong support for our hypothesis: Both of our experiments show that individuals’ choice processes are more describable in complex choice environments, which we interpret as evidence that decision-making becomes more procedural as complexity increases. We show that procedural decision-makers choose more consistently and exhibit fewer dominance violations, though we remain agnostic about the causal effect of procedures on decision quality. Additional secondary evidence suggests that procedural decision-making is a choice simplification that reduces the cognitive costs of decision-making."

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Another of his papers is a really creative investigation of human welfare:

What You Don't Know May Hurt You: A Revealed Preferences Approach by Gonzalo Arrieta and Lukas Bolte

Abstract: The dominant approach to welfare is based on revealed preferences and thus is restricted to settings where the individual knows their preferences have been fulfilled. We use a choosing-for-others framework to experimentally study welfare when what the individual believes to be true differs from what is actually true. About 42% of participants see welfare as independent of beliefs; 22% see welfare as only depending on beliefs; and 29% see a lower, but still positive, welfare effect when beliefs are fixed. Furthermore, the average participant values accurate beliefs. Our results suggest most people support the idea that welfare goes beyond awareness, which can inform media regulation, informational policies, and government communication.

 

Here's a figure from the instructions about the creation of "real" and "fake" inscribed copies of books. A third party judged the welfare to the recipient

"Our altruistically revealed preference paradigm consists of asking surrogate participants to trade off a monetary bonus given to the Receiver, and the Receiver getting the books with the original notes over those with the fake notes. The bonus amount is a surprise to the Receiver to minimize concerns that they use it to deduce which books they got (i.e., to maintain obliviousness). Our three requirements allow us to interpret the bonus amount that leaves participants indifferent between giving the original and fake notes as a measure of the change in the Receiver’s welfare. As a benchmark, we also elicit the welfare effect when the Receiver does learn which notes they get."

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Welcome to the club, Gonzalo.

Kurt Sweat defends his dissertation

Kurt Sweat defended his dissertation this week. As you can see in the picture below, we celebrated with the traditional toast, but instead of champagne we're drinking  In-N-Out milk shakes.

 

He and I are flanked by the other members of his committee: Itai Ashlagi, Paolo Somaini, Frank Wolak and Han Hong.  He was also advised by Dr. Chris Almond.

  His job market paper, and the other papers in his dissertation, all concern heart transplants.

Endogenous Priority in Centralized Matching Markets: The Design of the Heart Transplant Waitlist (Job Market Paper) 

[Link to current draft]

"Centralized matching markets that prioritize specific participants to achieve certain policy goals are common in practice, but priority is often assigned using endogenous characteristics of participants. In the heart transplant waitlist in the United States, the treatment that a patient receives is used to assign waitlist priority. Policymakers recently changed the prioritization in an attempt to reduce waitlist mortality by assigning higher priority to patients receiving specific treatments previously associated with high waitlist mortality. First, I document a significant response to waitlist incentives in treatments given and transplants that take place. Then, I develop and estimate a structural model of treatment and transplant choices to evaluate the effect of the policy change on patients' outcomes and doctors' decisions. I find three main results from my model. First, there is little change in aggregate survival, and the effect of the change has been mainly redistributive. Second, the change has effectively targeted patients with lower untransplanted survival, with these patients receiving higher expected survival under the current design. Third, the effect on survival is largely driven by changes in the decision to accept/decline offers for transplants rather than directly due to a change in treatment decisions. The policy implications suggest that future designs of the waitlist should disincentivize declining offers for transplants."

Welcome to the club, Kurt.

Erling Skancke defends his dissertation

 Erling Skancke defended his dissertation last week:

Here's his job market paper:

Welfare and Strategic Externalities in Matching Markets with Interviews (Job Market Paper) Recent debate in the medical literature has raised concerns about the pre-match interview process for residency and fellowship positions at hospitals. However, little is known about the economics of this decentralized process. In this paper, I build a game-theoretic model in which hospitals conduct costly interviews in order to learn their preferences over doctors. I show that increased interview activity by any hospital imposes an unambiguous negative welfare externality on all other hospitals. In equilibrium, both hospitals and doctors may be better off by a coordinated reduction in interview activity. The strategic externality is more subtle, and conditions are derived under which the game exhibits either strategic complementarities or substitutes. Moreover, an increase in market size may exacerbate the inefficiencies of the interview process, preventing agents from reaping the thick market benefits that would arise in the absence of the costly interviews. This effect increases participants' incentives to match outside of the centralized clearinghouse as markets become thicker, jeopardizing the long-term viability of the clearinghouse. The model also provides new insights into several market design interventions that have recently been proposed.

Congratulations, Erling! 

Welcome to the club.

David Zuckerman defends his dissertation

 David Zuckerman defended his dissertation yesterday.

Here are the papers he defended:

Preferences for Compensatory and Retributive Justice

I experimentally investigate third-party preferences for victim compensation and offender punishment when one party has harmed another. I find that if the harm is intentional, third parties not only display an increased demand for punishment, but also an increased demand for compensation. I refer to these additional demands for punishment and compensation as the demand for retributive justice and compensatory justice, respectively. Demand for retributive justice is positively correlated with demand for compensatory justice. However, third parties do not treat the two types of justice as substitutes or complements. Moreover, I generally find that these types of justices do not take victim knowledge of offender punishment nor offender knowledge of victim compensation into account. I then extend my investigation to a risky setting, where the offender's action may or may not end up harming the victim. I find that for both compensation and punishment, not only does the intent behind the action matter, but the consequences of the action as well. However, this is primarily driven by third-party distributional preferences; the outcome does not seem to affect the demand for retributive or compensatory justice.

A Theory of Chosen Preferences

(with B. Douglas Bernheim, Luca Braghieri, and Alejandro Martínez) [Online Appendix] [2019 Working Paper Version]

American Economic Review, Vol. 111, No. 2 (February 2021), pages 720-754

We propose and develop a theory of preference formation based on the idea that people evaluate their lives according to worldviews that provide accounts of success and failure, and that they choose those worldviews subject to feasibility constraints. Our framework highlights the role of mindset ï¬,exibility, a trait that determines the relative weights the decision maker places on her current and anticipated worldviews when evaluating future outcomes. We show that our theory generates rich behavioral dynamics, thereby illuminating a wide range of applications and providing potential accounts for a variety of observed phenomena.

Unseen Preferences: Homophily in Friendship Networks

Revise and Resubmit, Journal of Economic Behavior and Organization

Homophily is typically measured using a single dimension to define groups. However, people generally display preferences over multiple dimensions. I develop a simple model that characterizes agents both by a (discrete) "type" and a (continuous) "personality" value. Agents have preferences-for-similarity over both dimensions, but homophily is only measured with respect to type. I identify sufficient conditions on preferences such that a strongly stable matching exists, and show via simulations that the friendship patterns generated by these matchings qualitatively line up with several patterns noted in the data. The matchings can be calculated via an algorithm where agents "search" through utility space for friends. Increasing costs to friendship cause both within-group and systematic across-group heterogeneity in the extent of students' search through utility space. Majority-group "outliers" - those who must search an extensive amount in utility space for friends - form a disproportionate number of cross-group friendships. These outliers are the key reason why mid-sized groups exhibit the highest levels of homophily bias, a distinctive feature noted in prior literature.

Mazel tov, David.  Welcome to the club.

Süleyman Kerimov defends his dissertation

 Süleyman Kerimov defended his dissertation yesterday, in Stanford's MS&E department. He studies matching, and will teach at Rice next year.

His main advisors are both named Itai.

These are the papers he spoke about:

• Dynamic Matching: Characterizing and Achieving Constant Regret, with Itai Ashlagi and Itai Gurvich, . [pdf] [SSRN]


• Scrip Systems with Minimal Availability, with Itai Ashlagi, working paper.
  • Appeared as an extended abstract in the 15th Conference on Web and Internet Economics (WINE 2019).

Mazel tov and tebrikler, Suleyman.

Welcome to the club.

Alejandro Martínez-Marquina defends his dissertation

 Alejandro Martínez-Marquina defended his dissertation this week.

 The three papers he chose for his dissertation are these:

When a Town Wins the Lottery: Evidence from Spain

(with Christina Kent) [Slides] [Draft]

"How do local wealth shocks impact economic activity? For over two centuries, Spain has conducted a national lottery which often results in the random allocation of up to $800 million in cash to the citizens of one town. This is the only case in the world where individuals living in the same location randomly receive pure wealth shocks of this scale. Leveraging data on town-level lottery ticket expenditures, we compare winning towns to non-winning towns that had the same probability of winning. We find that although consumption increases, the lottery causes a slowdown in economic activity and deters new migration to towns that won in recent decades. However, an analysis of a century of lottery winners reveals large and persistent increases in population for towns that won in earlier periods."

The Burden of Household Debt

(with Mike Shi)

"We propose that holding debt causes worse financial decisions using a novel experimental design where we randomly assign debt. Our design isolates the consequences of holding debt while controlling for potential confounding factors such as initial wealth levels, selection, risk, and time preferences. Our findings show that debt causes behavioral biases detrimental to subjects' financial payoffs. However, subjects' strategies are not random but instead debt-biased, consistent with an additional penalty for holding negative balances. We refer to the financial losses caused by debt as the Burden of Debt and provide evidence that, under certain circumstances, these behavioral biases can compound and lead to substantial losses. Furthermore, we show in additional treatments how these debt-biased behaviors can also deter subjects from borrowing and forego profitable opportunities."

Ingraining Traditional Gender Roles in the Classroom: Evidence from the Spanish Social Service

[Slides]

"This study uses a regression discontinuity framework to examine the long- run effects of conservative education on women's' family and labor decisions. In 1939, the Spanish dictatorship created the Social service, a compulsory 6- month training program aimed at relegating women to the roles of mothers and housewives. We exploit the discontinuity induced by the sudden abolition of the Social Service, in addition to variation in the age of enrollment, to examine the consequences of attending the program. Using historical enrollment records and the universe of birth certificates, we find the Social Service was successful in instilling the regime's ideology. Women exposed to the class get married and have kids at younger ages, consistent with the desire to form a family sooner. In addition, they are more likely to declare being housewives when their first child is born. Future work will explore the underlying mechanisms and the effects on children by surveying women who enrolled around abolition."

Welcome to the club, Alejandro.

Aleandro ( top center) with Chenzi Xu, Muriel Niederle, Doug Bernheim, Al Roth, Ran Abramitzky

Akhil Vohra and Mike Shi defend their dissertations

 We're still locked out of the Economics building, but science progresses and dissertations are defended.  I've been remiss in celebrating them: here are two recent ones.

Akhil Vohra, whose job market paper I blogged about  here.

Akhil Vohra (top center) with Al Roth, Itai Ashlagi, Matt Jackson, Gabe Carroll and Fuhito Kojima

And Mike Shi, one of whose papers is this one:

The Burden of Household Debt  By ALEJANDRO MART´INEZ-MARQUINA and MIKE SHI *

Mike Shi (upper right) with Al Roth, Jeremy Bulow, Muriel Niederle, Luigi Pistaferri, and Nick Bloom

Welcome to the club, Akhil and Mike.

Eduardo Laguna Müggenburg explores the repugnance of price gouging, and defends his dissertation

 Eduardo Laguna successfully defended his Ph.D. dissertation last month. One of the papers he presented  (with Justin Holz and Rafael Jiménez-Duran) was an online experiment in which Amazon sellers of face masks and sanitizer at high prices were sampled, and subjects in the experiment were offered the opportunity to pay to have items be purchased from those sellers and donated to hospitals, and also to pay to have those sellers reported as price gougers to the  Department of Justice National Center for Disaster Fraud.  Some subjects were willing to buy, some were willing to pay to report, and some were willing to pay to avoid having sellers reported.

Here's the paper 

Quantifying repugnance to price gouging with an incentivized reporting experiment 

by Justin Holz, Rafael Jiménez-Duran and Eduardo Laguna-Müggenburg

Abstract: "Anti-price gouging laws are ubiquitous and people take costly actions to report violators to law-enforcement agencies, which suggests that they value punishing price increases during emergencies. We argue with a model that consumer reports contain information about repugnance to price gouging, or willingness to prevent third-party transactions (Roth, 2007). We conduct a field experiment during the first wave of COVID-19 to measure individuals’ willingness to pay to report sellers who increase prices of personal protective equipment. The willingness to pay to report is non-negligible, polarized, and responsive to the seller's price. We also find that repugnance is partly due to distaste for seller profits, depending on the product."

Remarkably, "Half of subjects who are willing to pay to report sellers are also willing to forgo the $5 gift card to have us donate PPE from a price-gouging seller."

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That is, there are substantial numbers of participants who are willing to pay to report the seller, but are also willing to pay for the experimenters to purchase from the seller and donate the PPE to a hospital.  

We often think of repugnance as partitioning the population—there are people who want to transact, and others who think the transaction shouldn’t happen.  The fact that some individuals can simultaneously have both these feelings is, I think,  one of the most striking results of this experiment—it shows just how complex repugnance can be. These are people who recognize that buying goods at inflated prices (and donating them to hospitals) may be efficient, and worth doing given the shortage,  but would still like to see the sellers fined or jailed.  

I'm reminded of this (third hand) story about a N. Carolina hurricane, in which people waiting in line to buy ice at high prices nevertheless applauded when police arrived to arrest the sellers for price gouging... They Clapped: Can Price-Gouging Laws Prohibit Scarcity?

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    Here's a picture from Eduardo's dissertation defense, conducted over Zoom:

Top: Matt Jackson, Eduardo Laguna, Al Roth

   Bottom: Larry Goulder, Chenzi Xu, Melanie Morten

Welcome to the club, Eduardo.

Qingyun Wu defends his dissertation--remotely

Qingyun Wu successfully defended his dissertation at Stanford today, remotely, as we are all sheltering in place from the coronavirus pandemic.

He presented three papers, the screenshot above is from the third.

1. The lattice of envy-free matchings." Games and Economic Behavior 109 (2018): 201-211.
2 Entering Classes in the College Admissions Model." 
3 "Forbidden Transactions and Black Markets." 

Welcome to the club, Qingyun.

Afshin Nikzad defends (x2)

Defense 2, (Offense 0).
Afshin Nikzad defended twice in eight days, to qualify for two Ph.D.s, one from Management Science and Engineering, in Operations Research, and one from Economics (in economics:).  Here are photos from his Economics defense.

Afshin Nikzad and some of his admirers: Philip Strack, Fuhito Kojima, Daniela Saban, Niloufar Salehi, Al Roth, Afshin, Paul Milgrom, and Itai Ashlagi

The papers he presented for his Economics defense were
Thickness and Competition in Ride-sharing Markets 
and 
Financing Transplant Costs of the Poor: A Dynamic Model of Global Kidney Exchange 

The papers he presented for his MS&E defense were 
Approximate Random Allocation Mechanisms 
and
What matters in tie-breaking rules? How competition guides design 


Welcome to the club(s), Afshin

Bobby Pakzad-Hurson defends his dissertation

Bobby Pakzad-Hurson defended his dissertation yesterday. (Successfully:) You can find his papers at the link. This celebratory photo was taken by Susie Gilbert.

Here's Bobby (in the suit, holding the bottle) with his committee: Fuhito Kojima, me, Nick Bloom, Matt Jackson and Itai Ashlagi.

Bobby's job market paper (with Zoe Cullen) was on pay transparency. He'll be going to Brown next year.

Welcome to the club, Bobby.

Stephanie Hurder defends her Ph.D. dissertation

Stephanie Hurder defended her dissertation at Harvard a few days ago. In the modern photoshop fashion, I got included in the post-defense photo even though I had skyped in from Stanford.

Al Roth, Larry Katz, Claudia Goldin, Stephanie Hurder, Chris Avery, and Pika

I blogged about her job market paper here, and her job market here.

Welcome to the club, Stephanie.

Nikhil Agarwal defends his Ph.D. dissertation

Nikhil Agarwal defended his Ph.D. dissertation earlier this week. Two members of his committee, me and Susan Athey, skyped in from Stanford. But in the age of photoshop, seeing isn't believing: here is a photo of the post-defense celebration as it happened, and as it would have happened if California were a suburb of Boston...

Parag Pathak, Nikhil Agarwal, Ariel Pakes

Al Roth, Parag Pathak, Nikhil Agarwal, Ariel Pakes and Susan Athey

I blogged about his job market paper here, and his job market here.

Welcome to the club, Nikhil.

Alex Peysakhovich defends his Ph.D. dissertation

Alex (tieless in suit), David Laibson, Drew Fudenberg, Uma Karmaker and me (via  Skype)

Skyping the post-defense champagne

Alex Peysakhovich defended his dissertation on Friday at Harvard; I skyped in from California. Alex is a man of many projects: the one he spent the most time talking about at his defense is this one:

"When Punishment Doesn't Pay: 'Cold Glow' and Decisions to Punish" (with  Aurelie Ouss).

Alex is a behavioral economist who is always looking to expand his horizons, and he'll be doing a postdoc this coming year with Dave Rand and Martin Nowak. Look for Alex (and Aurelie) on the market next year.

Welcome to the club, Alex.

Jacob Leshno defends his Ph.D. dissertation

Defense 4

Dr. Jacob Leshno (in suit:), and Al Roth, Susan Athey, and Ariel Pakes (Drew Fudenberg on skype)

And here is what the picture would have looked like if Drew had used photoshop instead of skype:

Drew looks on approvingly (in a photo doctored by the new doctor...)

The title of Jacob's dissertation is Essays in Market Design.  (How cool is that?)

The three papers he chose to include in his dissertation are

Dynamic Matching in Overloaded Systems (Job Market Paper)

In many assignment problems items arrive stochastically over time. When items are scarce agents form an overloaded waiting list and items are dynamically allocated as they arrive; two examples are public housing and organs for transplant. Even when all the scarce items are allocated, there is the efficiency question of how to assign the right items to the right agents. I develop a model in which impatient agents with heterogeneous preferences wait to be assigned scarce heterogeneous items that arrive stochastically over time. Social welfare is maximized by appropriately matching agents to items, but an individual impatient agent may misreport her preferences to receive an earlier mismatched item. To incentivize an agent to avoid mismatch, the policy needs to provide the agent with a (stochastic) guarantee of future assignment, which I model as putting the agents in a priority buffer-queue. I first consider a standard queue-based allocation policy and derive its welfare properties. To determine the optimal policy, I formulate the dynamic assignment problem as a dynamic mechanism design problem without transfers. The resulting optimal incentive compatible policy uses a buffer-queue of a new queueing policy, the uniform wait queue, to minimize the probability of mismatching agents. Finally, I derive a robustly optimal policy which uses a simple rule: giving equal priority to every agent who declines a mismatched item (a SIRO buffer-queue). This robustly optimal policy has several good properties that make it a compelling market design policy recommendation.

A Supply and Demand Framework for Two-Sided Matching Markets, with Eduardo Azevedo
(Extended abstract published in EC11 under the former name: "The college admissions problem with a continuum of students" )

We give a version of the Gale and Shapley (1962) college admissions problem where colleges have a large capacity and show that the resulting model allows for tractable analysis of matching markets. When colleges are large stable matchings can be described concisely by cutoffs, the admission thresholds at each college. Under broad conditions the model corresponds to the limit of large discrete matching problems.

Will a Decrease In The Minimum Wage Improve Training?, with Michael Schwarz

We show that firms that have a cost advantage in providing training can recoup training cost even in an almost frictionless labor market. Lowering the minimal legal wage can reduce the efficiency of training and harm welfare. In our model training contracts give positive surplus to workers that is not competed away. This explains the existence of intermediary services that essentially sell internship positions to college graduates.

Jacob is one of the group of job market candidates I blogged about here: Five Harvard candidates for the Economics job market this year (2011-12)

He will be going next year to a postdoc at Microsoft Research in Cambridge, after which he'll take up a position at Columbia GSB.

This concludes my defenses for the week (and the Offense never even got a point up on the board...)

Welcome to the club, Jacob.

Eduardo Azevedo defends his Ph.D. dissertation

Defense 3

Eduardo Azevedo (in suit:) having just fended off his committee: from left, Eric Budish, Al Roth, Oliver Hart, Susan Athey, Andrei Shleifer

Eduardo chose the following three of his papers to constitute his dissertation:

A Supply and Demand Framework for Two-Sided Matching Markets (Job Market Paper #1)
with Jacob Leshno
extended abstract published in EC11

Strategyproofness in the Large as a Desideratum for Market Design (Job Market Paper #2)
with Eric Budish

Evolutionary Origins of the Endowment Effect - Evidence from Hunter-Gatherers (PDF available upon request)
with Coren Apicella, Nicholas Christakis, and James Fowler

I earlier blogged about two of those papers:

A supply and demand model for stable matchings, by Eduardo Azevedo and Jacob Leshno
and

Market design in a future of trusted smart markets: paper by Eduardo Azevedo and Eric Budish

Eduardo is one of the group of job market candidates I blogged about here: Five Harvard candidates for the Economics job market this year (2011-12)

As I write it isn't clear whether he'll be working next year in Philadelphia, NYC, or Chicago, which will depend on his fiance's jobmarket, which is still to be concluded.

Welcome to the club, Eduardo.
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Update: May 11--It's Wharton.

Yuichiro Kamada defends his Ph.D. dissertation

Defense 2 (Offense 0)

Yuichiro (in suit:), with Tomasz Strzalecki and Al Roth (and Drew Fudenberg and Attila Ambrus via skype)

Yuichiro with the full defense team

Yuichiro had to choose three out of his many papers for his dissertation, which he called "Essays on Revision Games." Those papers all concern the difficult problem of analyzing incentives in non-stationary environments.

Multi-Agent Search with Deadline (joint with Nozomu Muto), December 31, 2011.(An earlier version of this paper referred to in the new version is here)

Revision Games (joint with Michihiro Kandori), December 31, 2011

Asynchronicity and Coordination in Common and Opposing Interest Games (joint with Riccardo Calcagno, Stefano Lovo, and Takuo Sugaya), March 2012, Revise and Resubmit, Theoretical Economics. (This paper is a result of a merger between two independent papers: Preopening and Equilibrium Selection by Calcagno and Lovo, and Asynchronous Revision Games with Deadline: Unique Equilibrium in Coordination Games by Kamada and Sugaya)

I earlier blogged about another of his papers, on the design of the market for new Japanese doctors:

Matching Japanese Doctors: problems with the current mechanisms, and suggestions for improvement by Yuichiro Kamada and Fuhito Kojima

Yuichiro is one of the group of job market candidates I blogged about here: Five Harvard candidates for the Economics job market this year (2011-12)

 He will be going next year to a postdoc at Yale, after which he'll take up a position at Berkeley-Haas.

Two more defenses are coming up this week.

 Welcome to the club, Yuichiro.

Katie Baldiga defends her Ph.D. dissertation

Defense 1 (Offense 0)

Katie Baldiga and her committee of admirers: Iris Bohnet, Al Roth, Jerry Green (and Drew Fudenberg via skype)
(Alternative caption: Katie B. got her Ph.D.)

The three papers in Katie's dissertation are so wide ranging that she characterizes them together as "Essays in Microeconomics." (I blogged about her experimental paper here.)

A Failure of Representative Democracy (Job Market Paper 1) 
In this paper, we study representative democracy, one of the most popular classes of collective decision-making mechanisms, and contrast it with direct democracy. In a direct democracy, individuals have the opportunity to vote over the alternatives in every choice problem the population faces. In a representative democracy, the population commits to a candidate ex ante who will then make choices on its behalf. While direct democracy is normatively appealing, representative democracy is the far more common institution because of its practical advantages. The key question, then, is whether representative democracy succeeds in implementing the choices that the group would make under direct democracy. We find that, in general, it does not. We analyze the theoretical setting in which the two methods are most likely to lead to the same choices, minimizing potential sources of distortion. We model a population as a distribution of voters with strict preferences over a finite set of alternatives and a candidate as an ordering of those alternatives that serves as a binding, contingent plan of action. We focus on the case where the direct democracy choices of the population are consistent with an ordering of the alternatives. We show that even in this case, where the normative recommendation of direct democracy is clear, representative democracy may not elect the candidate with this ordering.

Gender Differences in Willingness to Guess and the Implications for Test Scores (Job Market Paper 2) 
Multiple-choice tests play a large role in determining academic and professional outcomes. Performance on these tests hinges not only on a test-taker's knowledge of the material but also on his willingness to guess when unsure about the answer. In this paper, we present the results of an experiment that explores whether women skip more questions than men. The experimental test consists of practice questions from the World History and U.S. History SAT II subject tests; we vary the size of the penalty imposed for a wrong answer and the salience of the evaluative nature of the task. We find that when no penalty is assessed for a wrong answer, all test-takers answer every question. But, when there is a small penalty for wrong answers and the task is explicitly framed as an SAT, women answer significantly fewer questions than men. We see no differences in knowledge of the material or confidence in these test-takers, and differences in risk preferences fail to explain all of the observed gap. Because the gender gap exists only when the task is framed as an SAT, we argue that differences in competitive attitudes may drive the gender differences we observe. Finally, we show that, conditional on their knowledge of the material, test-takers who skip questions do significantly worse on our experimental test, putting women and more risk averse test-takers at a disadvantage.

Assent-Maximizing Social Choice with Jerry R. Green, forthcoming in Social Choice and Welfare
We take a decision theoretic approach to the classic social choice problem, using data on the frequency of choice problems to compute social choice functions. We define a family of social choice rules that depend on the population's preferences and on the probability distribution over the sets of feasible alternatives that the society will face. Our methods generalize the well-known Kemeny Rule. In the Kemeny Rule it is known a priori that the subset of feasible alternatives will be a pair. We define a distinct social choice function for each distribution over the feasible subsets. Our rules can be interpreted as distance minimization -- selecting the order closest to the population's preferences, using a metric on the orders that reflects the distribution over the possible feasible sets. The distance is the probability that two orders will disagree about the optimal choice from a randomly selected available set. We provide an algorithmic method to compute these metrics in the case where the probability of a given feasible set is a function only of its cardinality.

Katie is one of the group of job market candidates I blogged about here: Five Harvard candidates for the Economics job market this year (2011-12).

She and her significant other LC solved the two-body problem this year (!), and will be together at The Ohio State University, which is now more than ever a hotbed of experimental economics.

Three more defenses are coming up this week.

Welcome to the club, Katie.

Pro-social behavior of all kinds: Judd Kessler

Judd Kessler defended his dissertation yesterday (successfully, I should add:).

His work includes lab and field investigations of charitable giving, of provision of public goods, of cooperation in the presence or absence of contracts, of team production when pay is equal or unequal, and of the decision to be an organ donor.

His job market paper, “Signals of Support and Public Good Provision,” is unusual in the way it combines experiments both in the field and in the lab. The field experiment involves a big national charity’s regional campaign in about 200 firms, covering around 25,000 employees. One of the treatment conditions involved giving out buttons to all employees, which they could wear if they wished to express support for the charity. This turned out to have a surprisingly large effect on giving: it increased the number of donations and the amount donated by about a third. Another treatment involved giving out raffle tickets to those who contributed, and this did not have a positive effect on giving. The hypothesis is that the buttons (unlike the raffle tickets) provide information to coworkers about the level of support the charity enjoys, and that when they receive positive information about this they are more likely to contribute themselves.

But a field experiment is by nature imperfectly controlled, so Judd also conducted a lab experiment modeled on the field experiment (in which subjects also had an opportunity to contribute to a charity), but with careful controls in place to test for alternative hypotheses. The treatments in the field experiments already suggested that we aren’t seeing increased contributions because of gift exchange (i.e. the button isn’t regarded as a gift, as the raffle tickets might be), and what Judd finds in the lab is that the major effect of seeing another subject who has chosen to wear the button is that it increases a subject’s estimate of what the other subject will give, and this appears to be the mechanism through which contributions are increased. (Subjects also contribute more when wearing a pin, so this is a rational expectation.)

Judd’s field experiment and lab experiment complement each other; the lab experiment couldn’t have given a reliable prediction of the magnitude of the effect Judd observes in the field, while the field experiment leaves open many more hypotheses about the cause of this effect than does the lab experiment.

Welcome to the club, Judd.

Designing "hidden markets"--Sven Seuken

Yesterday Sven Seuken defended his dissertation, which is on the interface of CS and Economics. In particular, he is interested in designing both computerized marketplaces and the user interfaces through which participants will interact.

The essay that was his job market paper concerns a practical business idea for a centrally administered marketplace for peer-to-peer computer backup services that have to be consumed in bundles (e.g. bandwidth and memory are complements), but may be offered in different proportions by different users, at market prices that are posted through a user interface that makes it easy for a consumer to see what backup he requires, and what combinations of resources he can offer to the system to pay for his own services. A customer for the backup service must offer backup services to other customers, and the  centralized server keeps track of what resources are being used, and sets relative prices for different resources that are “hidden” in that they are revealed not as numerical prices, but as tradeoffs between backup capacity a consumer demands and various ways that he can supply the system with resources from his own computer (upload and download bandwidth and memory, and hours a day connected to the web).

That is, this is a market with complements, in which both bids and asks must be for packages of services, but in which customers can participate using a simple interface.

Market design itself is becoming a market with complementarities between economists and computer scientists. Sven may join his main advisor, David Parkes, in internalizing many of these complementarities himself. (The other members of his committee were Eric Horvitz, Yiling Chen, and me.) Since he is going to Zurich, he may also have the opportunity to join forces with Jacob Goeree and solidify a real center of market design there.


Welcome to the club, Sven.