If I were at the INFORMS meeting in Philadelphia, I'd enjoy lots of sessions on matching and market design, by a variety of (increasingly young) market designers.
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Session Information : Monday Nov 02, 08:00 - 09:30
Title: Matching Markets and Their ApplicationsChair: Thayer Morrill,NC State University, Raleigh, NC, United States of America, thayer_morrill@ncsu.edu
Abstract Details
Title: Incentives in the Course Allocation Problem Presenting Author: Hoda Atef Yekta,University of Connecticut School of Business, Storrs, CT, CT, United States of America, Hoda.AtefYekta@business.uconn.edu
Abstract: Kominers et al. (2011) introduced a heuristic for comparing incentives among the course allocation problem (CAP) algorithms. We investigate their method and adapt it to a more realistic setting with course overlap and a limited number of courses for each student. We compare algorithms including the bidding-point mechanism, the draft mechanism, and recently proposed algorithms like the proxy-agent second-price algorithm in their vulnerability to non-truthful bidding. Title: Near-optimal Stochastic Matching with Few Queries Presenting Author: John Dickerson,CMU, 9219 Gates-Hillman Center, Pittsburgh PA 15213, United States of America, dickerson@cs.cmu.edu
Co-Author: Avrim Blum,Professor, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, avrim@cs.cmu.edu
Nika Haghtalab,Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, nhaghtal@cs.cmu.edu
Ariel Procaccia,Professor, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, arielpro@cs.cmu.edu
Tuomas Sandholm,Professor, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, sandholm@cs.cmu.edu
Ankit Sharma,Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, ankits@cs.cmu.edu
Abstract: In kidney exchange, patients with kidney failure swap donors. Proposed swaps often fail before transplantation. We explore this phenomenon through the lens of stochastic matching, which deals with finding a maximum matching in a graph with unknown edges that are accessed via queries, and its generalization to k-set packing. We provide adaptive and non-adaptive algorithms that perform very few queries, and show that they perform well in theory and on data from the UNOS nationwide kidney exchange. Title: The Secure Boston Mechanism Presenting Author: Thayer Morrill,NC State University, Raleigh, NC, United States of America, thayer_morrill@ncsu.edu
Co-Author: Unut Dur,umutdur@gmail.com
Robert Hammond,Decision Analyst, Chevron, 1400 Smith St, Houston, United States of America, rhammond@chevron.com
Abstract: We introduce the first mechanism that Pareto dominates the Deferred Acceptance algorithm (DA) in equilibrium. Our algorithm, the Secure Boston Mechanism (sBM), is a hybrid between the Boston Mechanism and DA. It protects students that are initially guaranteed a school but otherwise adjusts priorities based on student rankings. We demonstrate that sBM always has an equilibrium that weakly dominates the DA assignment, and that in equilibrium no student receives worse than a fair assignment. Title: Mechanism Design for Team Formation Presenting Author: Yevgeniy Vorobeychik,Vanderbilt University, 401 Bowling Ave, Nashville TN, United States of America, eug.vorobey@gmail.com
Co-Author: Mason Wright,masondw@umich.edu
Abstract: We present the first formal mechanism design framework for team formation, building on recent combinatorial matching market design literature. We exhibit four mechanisms for this problem, two novel, two simple extensions of known mechanisms from other domains. We use extensive experiments to show our second novel mechanism, despite having no theoretical guarantees, empirically achieves good incentive compatibility, welfare, and fairness.
Session Information : Tuesday Nov 03, 16:30 - 18:00
Title: Dynamic Matching Markets
Chair: John Dickerson,CMU, 9219 Gates-Hillman Center, Pittsburgh PA 15213, United States of America, dickerson@cs.cmu.edu
Abstract Details
Title: Global Kidney Exchange
Presenting Author: Afshin Nikzad,Stanford University, 37 Angell Court, APT 116, Stanford Ca 94305, United States of America, afshin.nikzad@gmail.com
Co-Author: Mohammad Akbarpour,Stanford, Stanford, CA 94305, Stanford, United States of America, mohamwad@gmail.com
Alvin Roth,Stanford, Stanford, CA 94305, Stanford, United States of America, alroth@stanford.edu
Abstract: In some countries, many patients die after a few weeks of diagnosis mainly because the costs of kidney transplantation and dialysis are beyond the reach of most citizens. We analyze the two proposals in which patients with financial restrictions who have willing donors participate in kidney exchange without paying for surgery. Our proposals can save thousands of patients, while substantially decreasing the average dialysis costs; in particular, we prove that they are "self-financing" Title: Matching with Stochastic Arrival Presenting Author: Neil Thakral,Harvard, 1805 Cambridge Street, Cambridge MA, United States of America, nthakral@fas.harvard.edu
Abstract: We study matching in a dynamic setting, with applications to public-housing allocation. Objects of different types that arrive stochastically over time must be allocated to agents in a queue. When objects share priorities over agents, we propose an efficient, envy-free, and strategy-proof mechanism. The mechanism continues to satisfy these properties if and only if the priority relations are acyclic. Estimated welfare gains over existing housing-allocation procedures exceed $5000 per applicant. Title: Dynamic Kidney Exchange with Heterogeneous Types Presenting Author: Maximilien Burq,Student, MIT, 77 Massachusetts Avenue, Cambridge MA 02139, United States of America, mburq@mit.edu
Co-Author: Itai Ashlagi,MIT, 100 Main st, Cambridge Ma 02139, United States of America, iashlagi@mit.edu
Patrick Jaillet,MIT, 77 Massachusetts Avenue, Cambridge MA 02139, United States of America, jaillet@mit.edu
Vahideh Manshadi,Yale University, 165 Whitney Ave, Rm 3473, New Heaven, United States of America, vahideh.manshadi@yale.edu
Abstract: Kidney exchange programs face growing number of highly sensitized patients. We develop an online model that models such heterogeneity, and we prove that having some easy-to-match patients in the pool greatly reduces waiting times both in the presence of bilateral matching and chain matching. We provide simulations showing that some prioritizing leads to improved overall efficiency. Title: Competing Dynamic Matching Markets Presenting Author: Sanmay Das,WUSTL, One Brookings Dr, CB 1045, St. Louis MO 63130, United States of America, sanmay@wustl.edu
Co-Author: John Dickerson,CMU, 9219 Gates-Hillman Center, Pittsburgh PA 15213, United States of America, dickerson@cs.cmu.edu
Zhuoshu Li,WUSTL, One Brookings Dr, CB 1045, St. Louis MO 63130, United States of America, zhuoshuli@wustl.edu
Tuomas Sandholm,Professor, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, sandholm@cs.cmu.edu
Abstract: We extend a framework of dynamic matching due to Akbarpour et al. to characterize outcomes in cases where two rival matching markets compete. One market matches quickly while the other builds thickness by matching slowly. We present analytical and simulation results, both in general and for kidney exchange, demonstrating that rival markets increase overall loss compared to a single market that builds thickness.
Session Information : Sunday Nov 01, 13:30 - 15:00
Title: Revenue Management in Online AdvertisingChair: Hamid Nazerzadeh,University of Southern California, Bridge Memorial Hall, 3670 Trousdale Parkway, LOS ANGELES 90089, United States of America, hamidnz@marshall.usc.edu
Abstract Details
Title: Recent Results in Internet Advertising Allocations Presenting Author: Nitish Korula,Research Scientist, Google, New York, nitish@google.com
Co-Author: Hossein Esfandiari,University of Maryland, College Park MD, United States of America, hossein@cs.umd.edu
Vahab Mirrokni,Google Research, New York, United States of America, mirrokni@google.com
Morteza Zadimoghaddam,Google, New York NY 10011, United States of America, zadim@google.com
Abstract: Advertising provides the economic foundation of the Internet. Internet advertising applications motivate a host of optimization problems with unique challenges and as such, there is a large body of literature on optimizing various aspects of ad allocations. I will survey some of the recent work in this field, with special focus on two problems: Designing algorithms that work well in both adversarial and stochastic settings, and algorithms that balance multiple system objectives. Title: Multi-stage Intermediation in Online Internet Advertising Presenting Author: Ozan Candogan,University of Chicago, Booth School of Business, Chicago, United States of America, ozan.candogan@chicagobooth.edu
Co-Author: Santiago Balseiro,Assistant Professor, Duke University, 100 Fuqua Drive, Durham NC 27708, United States of America, srb43@duke.edu
Huseyin Gurkan,Duke, Duke University, Durham NC 27705, United States of America, huseyin.gurkan@duke.edu
Abstract: We consider a setting where an advertiser tries to acquire impressions from an ad exchange, through a chain of intermediaries. We characterize equilibrium profits of intermediaries as a function of their position in the chain. We consider three value distributions for the advertiser: (i) exponential, (ii) Pareto, (iii) uniform. We establish that in (i) all intermediaries have the same profit, whereas in (ii) and (iii) respectively downstream/upstream intermediaries have higher profits. Title: Adverse Selection and Auction Design for Internet Display Advertising Presenting Author: Nick Arnosti,Stanford University, Stanford CA, United States of America, narnosti@stanford.edu
Co-Author: Marissa Beck,Stanford University, 579 Serra Mall, Landau Economics, Stanford CA 94305, United States of America, mbeck22@gmail.com
Paul Milgrom,Stanford University, 579 Serra Mall, Landau Economics, Room 243, Stanford CA 94305, United States of America, milgrom@stanford.edu
Abstract: We model an online display advertising environment with brand advertisers and better-informed performance advertisers. We consider a mechanism which assigns the item to the highest bidder only when the ratio of the highest bid to the second highest bid is sufficiently large. For fat-tailed match-value distributions, this mechanism captures most of the gains from good matching and improves match values substantially compared to the common practice of setting aside impressions in advance. Title: Deals or No Deals: Contract Design for Selling Online Advertising Presenting Author: Hamid Nazerzadeh,University of Southern California, Bridge Memorial Hall, 3670 Trousdale Parkway, LOS ANGELES 90089, United States of America, hamidnz@marshall.usc.edu
Co-Author: Vahab Mirrokni,Google Research, New York, United States of America, mirrokni@google.com
Abstract: I will discuss some of the challenges in maximizing revenue of online advertising market. I will explain preferred deals: a new generation of contracts for selling display advertising that allow publishers to offer their inventory to “first look” buyers before the inventory is made available to other buyers (advertiser) in the general auction. I present algorithms for deal recommendation and show that deals can obtain significantly higher revenue than auctions.
I'd also be glad to hear
Centralized Seat Allocation for Engineering Colleges in India
Presenting Author: Yash Kanoria,Assistant Professor, Columbia University, New York, United States of America, ykanoria@columbia.edu
Abstract: The central government funds over 75 engineering colleges in India with 50,000 seats a year, and a diversity of programs and admissions criteria. We deploy a new, centralized, seat allocation mechanism, that accounts for the preferences of students as well as the admissions criteria for different colleges/programs using a deferred acceptance inspired approach.
Session Information | : Sunday Nov 01, 08:00 - 09:30 | |
Title: | Matching Markets | |
Chair: | Itai Ashlagi,MIT, 100 Main st, Cambridge Ma 02139, United States of America, iashlagi@mit.edu | |
Abstract Details | ||
Title: | Welfare-sensitive Assortment Optimization: An Application to School Choice | |
Presenting Author: | Peng Shi,MIT Operations Research Center, 1 Amherst Street, E40-149, Cambridge MA 02139, United States of America, pengshi@mit.edu | |
Abstract: | In many settings, a planner gives a set of options to agents, who choose among them to maximize their own value, but agents' choices have externalities on system revenue/cost. Examples include school choice, public housing, and health insurance. Welfare-Sensitive Assortment Optimization is to find a set of options that maximize the sum of agents' values and system revenue. We give efficient algorithms under MNL utilities and various constraints, and apply this to improve school choice in Boston. | |
Title: | Near Feasible Stable Matchings With Couples | |
Presenting Author: | Thanh Nguyen,Krannert School of Management, Purdue University, West Lafayette IN, United States of America, nguye161@purdue.edu | |
Co-Author: | Rakesh Vohra,University of Pennsylvania, 3718 Locust Walk, Philadelphia, United States of America, rvohra@seas.upenn.edu | |
Abstract: | The National Resident Matching program strives for a stable matching of medical students to teaching hospitals. With the presence of couples, stable matchings need not exist. For any student preferences, we show that each instance of a matching problem has a `nearby' instance with a stable matching. The nearby instance is obtained by perturbing the capacities of the hospitals. | |
Title: | Matching With Externalities | |
Presenting Author: | Jacob Leshno,Columbia University, 3022 Broadway,, Uris Hall, 406, New York NY 10027, United States of America, jleshno@columbia.edu | |
Abstract: | We show existence of stable matching in markets with a continuum of students. Stable matchings are characterized as rational expectations market clearing cutoffs. | |
Title: | What Matters in Tie-breaking Rules? How Competition Guides Design | |
Presenting Author: | Afshin Nikzad,Stanford University, 37 Angell Court, APT 116, Stanford Ca 94305, United States of America, afshin.nikzad@gmail.com | |
Co-Author: | Itai Ashlagi,MIT, 100 Main st, Cambridge Ma 02139, United States of America, iashlagi@mit.edu | |
Assaf Romm,Harvard, Boston, United States of America, assaf.romm@gmail.com | ||
Abstract: | School districts that adopt the Deferred Acceptance (DA) mechanism to assign students to schools face the tradeoff between fairness and efficiency when selecting how to break ties among equivalent students. We analyze a model with with random generated preferences for students and compare two mechanisms differing by their tie-breaking rules: DA with one single lottery (DA-STB) and DA with a separate lottery for each school (DA-MTB). We identify that the balance between supply and demand in the market is a prominent factor when selecting a tie-breaking rule. When there is a surplus of seats, we show that neither random assignments under these mechanisms stochastically dominates each other, and, the variance of student's assignments is larger under DA-STB. However, we show that there is essentially no tradeoff between fairness and efficiency when there is a shortage of seats: not only that DA-STB (almost) stochastically dominates DA-MTB, it also results in a smaller variance in student's rankings. We further find that under DA-MTB many pairs of students would benefit from directly exchanging assignments ex post when there is a shortage of seats, while only few such pairs exist when there is a surplus of seats. Our findings suggest that it is more desirable that ``popular" schools use a single lottery over a separate lottery in order to break ties, while in other schools there is a real tradeoff. | |
and
Title: | Two-Sided Matching Markets | |
Chair: | Peng Shi,MIT Operations Research Center, 1 Amherst Street, E40-149, Cambridge MA 02139, United States of America, pengshi@mit.edu | |
Co-Chair: | Yash Kanoria,Assistant Professor, Columbia University, New York, United States of America, ykanoria@columbia.edu | |
Itai Ashlagi,MIT, 100 Main st, Cambridge Ma 02139, United States of America, iashlagi@mit.edu | ||
Abstract Details | ||
Title: | On the Efficiency of Stable Matchings in Large Markets | |
Presenting Author: | Sangmok Lee,Univ of Pennsylvania, 3718 Locust Walk, Philadelphia, United States of America, sangmok@sas.upenn.edu | |
Co-Author: | Leeat Yariv,Caltech, 1200 E california Blvd, Pasadena, United States of America, lyariv@hss.caltech.edu | |
Abstract: | We study the wedge between stability and efficiency in large one-to-one matching markets. We show stable matchings are efficient asymptotically for a large class of preferences. In these environments, stability remains an appealing objective even on efficiency grounds, and monetary transfers are not necessary for efficiency purposes. Nonetheless, for severely imbalanced markets, when preferences entail sufficient idiosyncrasies, stable outcomes may be inefficient even asymptotically. | |
Title: | Short Lists in Centralized Clearinghouses | |
Presenting Author: | Nick Arnosti,Stanford University, Stanford CA, United States of America, narnosti@stanford.edu | |
Abstract: | In the presence of frictions, participants in centralized clearinghouses generally fail to list all acceptable match partners. As a consequence, mutually acceptable pairs are left unmatched. The number of unmatched agents (and the happiness of matched agents) depends crucially on the structure of correlations in participants' preferences. This work identifies a fundamental tradeoff between match quality and quantity, and uses this to offer guidance for the design of school choice mechanisms. | |
Title: | How Much Choice is There in Two-sided Matching Markets? | |
Presenting Author: | Itai Ashlagi,MIT, 100 Main st, Cambridge Ma 02139, United States of America, iashlagi@mit.edu | |
Abstract: | We study the structure of two-sided random matching markets with tiers. Our results provide insights on the amount of choice agents have in the core. |
Session Information | : Sunday Nov 01, 13:30 - 15:00 | |
Title: | Market Design | |
Chair: | Gabriel Weintraub,Professor, Columbia University, Uris Hall, New York NY 10027, United States of America, gyw2105@columbia.edu | |
Abstract Details | ||
Title: | Incentive Issues in Paired Organ Donation | |
Presenting Author: | Eduardo Azevedo,Assistant Professor, Wharton, 3620 Locust Walk, Wharton, SHDH 1400, Philadelphia Pe 19102, United States of America, eazevedo@wharton.upenn.edu | |
Co-Author: | Nikhil Agarwal,MIT, 77 Mass Ave, Cambridge MA, United States of America, agarwaln@mit.edu | |
Itai Ashlagi,MIT, 100 Main st, Cambridge Ma 02139, United States of America, iashlagi@mit.edu | ||
Clayton Featherstone,Wharton, 3620 Locust Walk, Wharton, SHDH 1400, Philadelphia Pe 19102, United States of America, claytonf@wharton.upenn.edu | ||
Abstract: | In the last few years a new type of organ donation has arisen. In a paired kidney exchange two recipients with incompatible live donors receive organs from each other's live donor. Sometimes transactions involve more recipients and/or donors. While many exchanges happen in a decentralized way, others happen in large centralized exchanges. We empirically examine how agents in these markets respond to incentives and whether incentives are misaligned with social goals. | |
Title: | Optimal Procurement Mechanisms for Differentiated Products | |
Presenting Author: | Gabriel Weintraub,Professor, Columbia University, Uris Hall, New York NY 10027, United States of America, gyw2105@columbia.edu | |
Co-Author: | Daniela Saban,Stanford University, 655 Knight Way, Stanford CA, United States of America, dsaban@stanford.edu | |
Abstract: | We study the mechanism design problem faced by a buyer that selects an assortment of differentiated products and unit prices from a set of suppliers with private costs. Then, consumers can choose their most preferred product from this set. The buyer maximizes consumer surplus; to do so, he must balance the trade-off between variety and price competition. We characterize the optimal mechanism and use these results to analyze practical mechanisms. | |
Title: | Efficiency and Stability in Large Matching Markets | |
Presenting Author: | Yeon-koo Che,Columbia University, 420 West 118th Street, 1029 IAB, New York NY, United States of America, yeonkooche@gmail.com | |
Co-Author: | Olivier Tercieux,Professor, Paris School of Economics, Department of Economics, Paris, France, tercieux@pse.ens.fr | |
Abstract: | We study efficient and stable mechanisms in matching markets when the number of agents is large and individuals' preferences and priorities are drawn randomly. When agents' preferences are correlated over objects, the prevailing mechanisms are either inefficient or unstable even in the asymptotic sense. We propose a variant of deferred acceptance which is asymptotically efficient, asymptotically stable and also asymptotically incentive compatible. | |
Title: | Market Fragmentation | |
Presenting Author: | Rakesh Vohra,University of Pennsylvania, 3718 Locust Walk, Philadelphia, United States of America, rvohra@seas.upenn.edu | |
Co-Author: | Ahmad Peivandi,Participation And Unbiased Pricing In Cds Settlement Mechanisms, Georgia State University, 35 Broad St, Atlanta, United States of America, apeivandi@gsu.edu | |
Abstract: | Centralized markets reduce the costs of search for buyers and sellers. Their `thickness' increases the chance of of order execution at competitive prices. In spite of the incentives to consolidate, some markets, have fragmented into multiple trading venues. We argue in this paper that fragmentation is an unavoidable feature of any centralized exchange. Our argument introduces a new way to think about participation in a mechanism when the outside option is endogenous. | |
Session Information : Monday Nov 02, 08:00 - 09:30
Title: Matching Markets and Their ApplicationsChair: Thayer Morrill,NC State University, Raleigh, NC, United States of America, thayer_morrill@ncsu.edu
Abstract Details
Title: Incentives in the Course Allocation Problem Presenting Author: Hoda Atef Yekta,University of Connecticut School of Business, Storrs, CT, CT, United States of America, Hoda.AtefYekta@business.uconn.edu
Abstract: Kominers et al. (2011) introduced a heuristic for comparing incentives among the course allocation problem (CAP) algorithms. We investigate their method and adapt it to a more realistic setting with course overlap and a limited number of courses for each student. We compare algorithms including the bidding-point mechanism, the draft mechanism, and recently proposed algorithms like the proxy-agent second-price algorithm in their vulnerability to non-truthful bidding. Title: Near-optimal Stochastic Matching with Few Queries Presenting Author: John Dickerson,CMU, 9219 Gates-Hillman Center, Pittsburgh PA 15213, United States of America, dickerson@cs.cmu.edu
Co-Author: Avrim Blum,Professor, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, avrim@cs.cmu.edu
Nika Haghtalab,Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, nhaghtal@cs.cmu.edu
Ariel Procaccia,Professor, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, arielpro@cs.cmu.edu
Tuomas Sandholm,Professor, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, sandholm@cs.cmu.edu
Ankit Sharma,Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, ankits@cs.cmu.edu
Abstract: In kidney exchange, patients with kidney failure swap donors. Proposed swaps often fail before transplantation. We explore this phenomenon through the lens of stochastic matching, which deals with finding a maximum matching in a graph with unknown edges that are accessed via queries, and its generalization to k-set packing. We provide adaptive and non-adaptive algorithms that perform very few queries, and show that they perform well in theory and on data from the UNOS nationwide kidney exchange. Title: The Secure Boston Mechanism Presenting Author: Thayer Morrill,NC State University, Raleigh, NC, United States of America, thayer_morrill@ncsu.edu
Co-Author: Unut Dur,umutdur@gmail.com
Robert Hammond,Decision Analyst, Chevron, 1400 Smith St, Houston, United States of America, rhammond@chevron.com
Abstract: We introduce the first mechanism that Pareto dominates the Deferred Acceptance algorithm (DA) in equilibrium. Our algorithm, the Secure Boston Mechanism (sBM), is a hybrid between the Boston Mechanism and DA. It protects students that are initially guaranteed a school but otherwise adjusts priorities based on student rankings. We demonstrate that sBM always has an equilibrium that weakly dominates the DA assignment, and that in equilibrium no student receives worse than a fair assignment. Title: Mechanism Design for Team Formation Presenting Author: Yevgeniy Vorobeychik,Vanderbilt University, 401 Bowling Ave, Nashville TN, United States of America, eug.vorobey@gmail.com
Co-Author: Mason Wright,masondw@umich.edu
Abstract: We present the first formal mechanism design framework for team formation, building on recent combinatorial matching market design literature. We exhibit four mechanisms for this problem, two novel, two simple extensions of known mechanisms from other domains. We use extensive experiments to show our second novel mechanism, despite having no theoretical guarantees, empirically achieves good incentive compatibility, welfare, and fairness.
Session Information : Tuesday Nov 03, 16:30 - 18:00
Title: Dynamic Matching Markets
Chair: John Dickerson,CMU, 9219 Gates-Hillman Center, Pittsburgh PA 15213, United States of America, dickerson@cs.cmu.edu
Abstract Details
Title: Global Kidney Exchange
Presenting Author: Afshin Nikzad,Stanford University, 37 Angell Court, APT 116, Stanford Ca 94305, United States of America, afshin.nikzad@gmail.com
Co-Author: Mohammad Akbarpour,Stanford, Stanford, CA 94305, Stanford, United States of America, mohamwad@gmail.com
Alvin Roth,Stanford, Stanford, CA 94305, Stanford, United States of America, alroth@stanford.edu
Abstract: In some countries, many patients die after a few weeks of diagnosis mainly because the costs of kidney transplantation and dialysis are beyond the reach of most citizens. We analyze the two proposals in which patients with financial restrictions who have willing donors participate in kidney exchange without paying for surgery. Our proposals can save thousands of patients, while substantially decreasing the average dialysis costs; in particular, we prove that they are "self-financing" Title: Matching with Stochastic Arrival Presenting Author: Neil Thakral,Harvard, 1805 Cambridge Street, Cambridge MA, United States of America, nthakral@fas.harvard.edu
Abstract: We study matching in a dynamic setting, with applications to public-housing allocation. Objects of different types that arrive stochastically over time must be allocated to agents in a queue. When objects share priorities over agents, we propose an efficient, envy-free, and strategy-proof mechanism. The mechanism continues to satisfy these properties if and only if the priority relations are acyclic. Estimated welfare gains over existing housing-allocation procedures exceed $5000 per applicant. Title: Dynamic Kidney Exchange with Heterogeneous Types Presenting Author: Maximilien Burq,Student, MIT, 77 Massachusetts Avenue, Cambridge MA 02139, United States of America, mburq@mit.edu
Co-Author: Itai Ashlagi,MIT, 100 Main st, Cambridge Ma 02139, United States of America, iashlagi@mit.edu
Patrick Jaillet,MIT, 77 Massachusetts Avenue, Cambridge MA 02139, United States of America, jaillet@mit.edu
Vahideh Manshadi,Yale University, 165 Whitney Ave, Rm 3473, New Heaven, United States of America, vahideh.manshadi@yale.edu
Abstract: Kidney exchange programs face growing number of highly sensitized patients. We develop an online model that models such heterogeneity, and we prove that having some easy-to-match patients in the pool greatly reduces waiting times both in the presence of bilateral matching and chain matching. We provide simulations showing that some prioritizing leads to improved overall efficiency. Title: Competing Dynamic Matching Markets Presenting Author: Sanmay Das,WUSTL, One Brookings Dr, CB 1045, St. Louis MO 63130, United States of America, sanmay@wustl.edu
Co-Author: John Dickerson,CMU, 9219 Gates-Hillman Center, Pittsburgh PA 15213, United States of America, dickerson@cs.cmu.edu
Zhuoshu Li,WUSTL, One Brookings Dr, CB 1045, St. Louis MO 63130, United States of America, zhuoshuli@wustl.edu
Tuomas Sandholm,Professor, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, sandholm@cs.cmu.edu
Abstract: We extend a framework of dynamic matching due to Akbarpour et al. to characterize outcomes in cases where two rival matching markets compete. One market matches quickly while the other builds thickness by matching slowly. We present analytical and simulation results, both in general and for kidney exchange, demonstrating that rival markets increase overall loss compared to a single market that builds thickness.
Session Information | : Tuesday Nov 03, 11:00 - 12:30 | |
Title: | Empirical Market Design | |
Chair: | Peng Shi,MIT Operations Research Center, 1 Amherst Street, E40-149, Cambridge MA 02139, United States of America, pengshi@mit.edu | |
Abstract Details | ||
Title: | Market Congestion and Application Costs | |
Presenting Author: | John Horton,Assistant Professor, NYU Stern School of Business, 44 West Fourth Street, Kaufman Management Center, New York NY 10012, United States of America, John.Horton@stern.nyu.edu | |
Co-Author: | Dana Chandler,Civis Analytics, West Loop, Chicago IL, United States of America, dchandler@gmail.com | |
Ramesh Johari,Stanford University, 475 Via Ortega, Stanford Ca 94305, United States of America, ramesh.johari@stanford.edu | ||
Abstract: | We report the results of an experimental intervention that increased the cost of applying to vacancies in an online labor market by requiring workers to answer questions about the job. Although the ordeal positively selected candidates, it was the information in the answers that mattered for match formation. Although the overall number of matches and speed to fill a vacancy was unchanged, employers engaged in less recruiting activities and formed higher quality matches. | |
Title: | Experiments as Instruments: Heterogeneous Position Effects in Sponsored Search Auctions | |
Presenting Author: | Justin Rao,Researcher, Microsoft Research, 641 Avenue of Americas, New York NY 10014, United States of America, Justin.Rao@microsoft.com | |
Co-Author: | Matthew Goldman,UCSD, 9500 Gilman Dr., La Jolla CA 92093, United States of America, mrgoldman@ucsd.edu | |
Abstract: | The Generalized Second Price auction has been shown to achieve an efficient allocation and favorable revenue properties provided the causal impact of ad position on user click probabilities is a constant the scaling factor for all ads. We develop a novel method to re-purpose internal business experimentation at a major search engine and we strongly reject the conventional multiplicatively-separable model, instead finding substantial heterogeneity of the causal impact of position on CTR. | |
Title: | Optimal Design of Two-sided Market Platforms: An Empirical Case Study of Ebay | |
Presenting Author: | Brent Hickman,Assistant Professor Of Economics, University of Chicago, 1226 E 59th St, Chicago IL 60637, United States of America, hickmanbr@uchicago.edu | |
Co-Author: | Aaron Bodoh-creed,Assistant Professor Of Economics, Haas School of Business, University of California, Berkeley, S545 Student Services Building, Berkeley CA 94720, United States of America, acreed@berkeley.edu | |
Joern Boehnke,Postdoctoral Fellow, Harvard University Center of Mathematical Sciences and Applications, Science Center 325, One Oxford Street, Cambridge MA 02138, United States of America, jboehnke@uchicago.edu | ||
Abstract: | We investigate design of platform markets that house many auctions over time. We combine a unique dataset with a model of bidding where the option value of re-entering the market creates incentive for buyers to shade bids below private valuations in the current period. We show the model is identified using the Bellman equation for a representative bidder. We estimate the model and investigate the degree to which eBay is able to reduce transaction costs and approach the efficient allocation. | |
Title: | Stability of Demand Models Across Policy Reforms: An Emperical Study with Boston Public Schools | |
Presenting Author: | Peng Shi,MIT Operations Research Center, 1 Amherst Street, E40-149, Cambridge MA 02139, United States of America, pengshi@mit.edu | |
Co-Author: | Parag Pathak,MIT, 77 Massachusetts Avenue, Building E17, Room 240, Cambridge MA 02139, United States of America, ppathak@mit.edu | |
Abstract: | In counterfactual analysis using demand modelling, an important but seldom checked assumption is that the proposed reform does not affect the demand model. We validate this assumption across a major school choice reform in Boston in 2014. To control for post-analysis bias, we precommit to forecasts before the reform. We find that while our prediction of the number of applicants were off, the logit and mixed-logit demand models we fit were stable before and after the reform. | |
Session Information | : Tuesday Nov 03, 13:30 - 15:00 | |
Title: | Kidney Allocation and Exchange | |
Chair: | Naoru Koizumi,Assoc Professor, GMU, 3351 N Fairfax Dr, Arlington VA 22203, United States of America, nkoizumi@gmu.edu | |
Abstract Details | ||
Title: | The Dynamics of Kidney Exchange | |
Presenting Author: | John Dickerson,CMU, 9219 Gates-Hillman Center, Pittsburgh PA 15213, United States of America, dickerson@cs.cmu.edu | |
Co-Author: | Tuomas Sandholm,Professor, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh PA 15213, United States of America, sandholm@cs.cmu.edu | |
Abstract: | We discuss analytic, optimization, and game-theoretic approaches to matching in dynamic kidney exchange. We consider dynamism (i) at the post-match pre-transplant stage (ii) as patients and donors arrive and depart over time, and (iii) as multiple exchanges compete for overlapping sets of participants. We empirically validate our models and theoretical results on over 150 match runs of the UNOS national kidney exchange. | |
Title: | A New Model to Decide Kidney–offer Admissibility Dependent on Patients' Lifetime Failure Rate | |
Presenting Author: | Michael Bendersky,Ben Gurion University of the Negev, Beersheba, Israel, michael.bendersky@gmail.com | |
Co-Author: | Israel David,Ben Gurion University of the Negev, Beersheba, Beersheba, Israel, idavid@bgu.ac.il | |
Abstract: | We propose a new model to decide kidney-offer admissibility depending on patient's age, estimated lifetime probabilistic profile and prospects on the waiting list. We allow for a broad family of lifetime distributions - Gamma - thus enabling flexible modeling of one's survival under dialysis. It yields the optimal critical times for acceptance of offers of different qualities and may serve the organizer of a donation program, the surgeon and the individual recipient practicing patient-choice. | |
Title: | Preemptive Approach to Kidney Allocation in USA | |
Presenting Author: | Philip Appiahk-Kubi,Ohio University, 14 Pine ST, APT #1B, The Plains Oh 45780, United States of America, pa809911@ohio.edu | |
Abstract: | The new kidney allocation policy improves kidney utilization. However, the policy has no consideration for allocation of cadaveric kidneys under emergency situations; a problem observed by the National Kidney Foundation. This research evaluates a point scoring model with considerations for emergency allocation. Simulated results indicate that the model minimizes number of waitlist deaths by 2% while prioritizing sensitive candidates and waiting time. | |
Title: | Optimal Integration of Kidney Exchange Programs with Antibody Reduction Therapy | |
Presenting Author: | Naoru Koizumi,Assoc Professor, GMU, 3351 N Fairfax Dr, Arlington VA 22203, United States of America, nkoizumi@gmu.edu | |
Co-Author: | Monica Gentili,Georgia Tech, North Ave NW, Atlanta GA, United States of America, mgentili3@mail.gatech.edu | |
Keith Melancon,George Washington University Hospital, 900 23rd St NW, Washington DC, United States of America, jmelancon@mfa.gwu.edu | ||
Abstract: | Kidney paired donation (KPD) allows incompatible pairs to exchange kidneys with other incompatible pairs. However, evidence suggests there stills exist barriers to KPD utilization, especially among difficult-to-match transplant candidates and positive actual or virtual crossmatches. Using mathematical models, we investigate how to optimally integrate antibody reduction therapy in KPD to increase successful living-donor kidney transplants among difficult to match candidates. | |
Session Information : Sunday Nov 01, 13:30 - 15:00
Title: Revenue Management in Online AdvertisingChair: Hamid Nazerzadeh,University of Southern California, Bridge Memorial Hall, 3670 Trousdale Parkway, LOS ANGELES 90089, United States of America, hamidnz@marshall.usc.edu
Abstract Details
Title: Recent Results in Internet Advertising Allocations Presenting Author: Nitish Korula,Research Scientist, Google, New York, nitish@google.com
Co-Author: Hossein Esfandiari,University of Maryland, College Park MD, United States of America, hossein@cs.umd.edu
Vahab Mirrokni,Google Research, New York, United States of America, mirrokni@google.com
Morteza Zadimoghaddam,Google, New York NY 10011, United States of America, zadim@google.com
Abstract: Advertising provides the economic foundation of the Internet. Internet advertising applications motivate a host of optimization problems with unique challenges and as such, there is a large body of literature on optimizing various aspects of ad allocations. I will survey some of the recent work in this field, with special focus on two problems: Designing algorithms that work well in both adversarial and stochastic settings, and algorithms that balance multiple system objectives. Title: Multi-stage Intermediation in Online Internet Advertising Presenting Author: Ozan Candogan,University of Chicago, Booth School of Business, Chicago, United States of America, ozan.candogan@chicagobooth.edu
Co-Author: Santiago Balseiro,Assistant Professor, Duke University, 100 Fuqua Drive, Durham NC 27708, United States of America, srb43@duke.edu
Huseyin Gurkan,Duke, Duke University, Durham NC 27705, United States of America, huseyin.gurkan@duke.edu
Abstract: We consider a setting where an advertiser tries to acquire impressions from an ad exchange, through a chain of intermediaries. We characterize equilibrium profits of intermediaries as a function of their position in the chain. We consider three value distributions for the advertiser: (i) exponential, (ii) Pareto, (iii) uniform. We establish that in (i) all intermediaries have the same profit, whereas in (ii) and (iii) respectively downstream/upstream intermediaries have higher profits. Title: Adverse Selection and Auction Design for Internet Display Advertising Presenting Author: Nick Arnosti,Stanford University, Stanford CA, United States of America, narnosti@stanford.edu
Co-Author: Marissa Beck,Stanford University, 579 Serra Mall, Landau Economics, Stanford CA 94305, United States of America, mbeck22@gmail.com
Paul Milgrom,Stanford University, 579 Serra Mall, Landau Economics, Room 243, Stanford CA 94305, United States of America, milgrom@stanford.edu
Abstract: We model an online display advertising environment with brand advertisers and better-informed performance advertisers. We consider a mechanism which assigns the item to the highest bidder only when the ratio of the highest bid to the second highest bid is sufficiently large. For fat-tailed match-value distributions, this mechanism captures most of the gains from good matching and improves match values substantially compared to the common practice of setting aside impressions in advance. Title: Deals or No Deals: Contract Design for Selling Online Advertising Presenting Author: Hamid Nazerzadeh,University of Southern California, Bridge Memorial Hall, 3670 Trousdale Parkway, LOS ANGELES 90089, United States of America, hamidnz@marshall.usc.edu
Co-Author: Vahab Mirrokni,Google Research, New York, United States of America, mirrokni@google.com
Abstract: I will discuss some of the challenges in maximizing revenue of online advertising market. I will explain preferred deals: a new generation of contracts for selling display advertising that allow publishers to offer their inventory to “first look” buyers before the inventory is made available to other buyers (advertiser) in the general auction. I present algorithms for deal recommendation and show that deals can obtain significantly higher revenue than auctions.
I'd also be glad to hear
Centralized Seat Allocation for Engineering Colleges in India
Presenting Author: Yash Kanoria,Assistant Professor, Columbia University, New York, United States of America, ykanoria@columbia.edu
Abstract: The central government funds over 75 engineering colleges in India with 50,000 seats a year, and a diversity of programs and admissions criteria. We deploy a new, centralized, seat allocation mechanism, that accounts for the preferences of students as well as the admissions criteria for different colleges/programs using a deferred acceptance inspired approach.