INFORMS 2021 Program Book

INFORMS Anaheim 2021

TC03

3 - Profit Maximizing Hub Network Design with Flow Threshold And Time-Sensitive Demand Sibel Alumur Alev, University of Waterloo, Waterloo, ON, N2L 3G1, Canada, Gita Taherkhani We model a profit maximizing hub network design problem in which the demand of some origin-destination pairs can remain unserved. We adopt a flow threshold for incorporating economies of scale so that if the flow routed on a link exceeds the given threshold, no matter if it is an inter-hub link or an allocation link, the transportation cost on this link is to be discounted. In this setting, we do not explicitly decide on the locations of hubs, but rather decide on the connections with the discounted flow. The aim is to build a network to consolidate flows and reduce the transportation as well as the cost of building this network. Moreover, we model time-sensitive demand and incorporate time limits for delivering demand at its destination as commonly faced in the design of less-than-truckload or truckload transportation networks. TC03 CC Ballroom C / Virtual Theater 3 Hybrid Platform Design for Social Good Sponsored: Auctions and Market Design Sponsored Session Chair: Vahideh Manshadi, Yale University, CT, United States Co-Chair: Scott Rodilitz, Yale, New Haven, CT, 06511-2572, United States 1 - Improving Kidney Exchange via Pre-screening Duncan McElfresh, University of Maryland, College Park, Palo Alto, CA, 94306, United States Planned transplants in kidney exchanges fail for a variety of reasons—if the donor organ is rejected by the recipient’s medical team, or if the donor and recipient are found to be medically incompatible. Failed transplants can “cascade” through an exchange, causing substantial delays for transplant recipients. Many optimization- based approaches have been designed to avoid these failures; however most exchanges cannot implement these methods, due to legal and policy constraints. Instead, we consider a setting where exchanges can query recipient preferences— asking whether they would accept a particular transplant. We characterize this as an optimization problem, in which the exchange program (a) queries a transplants before committing to a matching, and (b) constructs a matching according to fixed policy. 2 - Fair Algorithms for Selecting Citizens’ Assemblies Paul Gölz, Carnegie Mellon University, Pittsburgh, PA, United States, Bailey Flanagan, Anupam Gupta, Brett Henning, Ariel Procaccia Recently, there has been a global surge in citizens’ assemblies: panels of randomly-selected citizens weighing in on a policy question. Since these panels must proportionally represent many demographic groups, the selection algorithms currently used for choosing panels select different individuals with highly unequal probabilities. We develop selection algorithms that satisfy the given quotas while choosing pool members with probabilities as close to equal as possible. We have implemented one such algorithm, which has been adopted by a number of organizations around the world and has been used to select dozens of citizens’ assemblies. 3 - Simple and Optimal Contract Design for Payment for Ecosystem Services Wanyi Li, Stanford University, Stanford, CA, United States, Itai Ashlagi, Irene Yuan Lo Many countries have adopted Payment for Ecosystem Services (PES) programs to reduce deforestation. Empirical evaluations find such programs, which pay forest owners to conserve forest, can lead to anywhere from no impact to a 50% reduction in deforestation level. To better understand PES contracts, we use a principal-agent model, in which the agent with some amount of initial forest land has a privately-known baseline conservation level. Commonly-used conditional contracts perform well when the environmental value of forest is sufficiently high or sufficiently low, but can do arbitrarily poorly compared with the optimal contract for intermediate values. We identify a linear contract with a distribution- free per-unit price that guarantees at least half of the optimal contract payoff. A numerical study using United States land use data supports our findings.

4 - Optimization Enables Transparent and Inclusive Policies: Improving School Schedules in San Francisco Arthur J. Delarue, MIT, Cambridge, MA, 02139-4310, United States, Zhen Lian, Sebastien Martin We developed a multiobjective optimization framework to evaluate the policy tradeoffs of changing start times at San Francisco Unified School District (SFUSD). We used our methodology to optimize start times for SFUSD’s post-COVID reopening in the spring of 2021. In addition, we developed participative tools that SFUSD used to select new start times for the Fall of 2021, satisfying a number of community priorities, and leading to projected transportation savings of up to $3 million per year.

TC04 CC Ballroom D / Virtual Theater 4

Hybrid Publications and Review Process Informs Special Session: Junior Faculty Interest Group Informs Special Session Session Chair: Hrayer Aprahamian, Texas A&M University, College Station, TX, 77840, United States 1 - Moderator Hrayer Aprahamian, Texas A&M University, College Station, TX, 77840, United States 2 - Panelist Cole Smith, Syracuse University, Syracuse, NY, 13244-1240, United States 3 - Panelist John R. Birge, University of Chicago, Chicago, IL, 60637-1656, United States 4 - Panelist Douglas R. Shier, Clemson University, Pittsboro, NC, 27312-8612, United States 5 - Panelist David Simchi-Levi, Massachusetts Institute of Technology, Cambridge, MA, 02139-4301, United States 6 - Panelist Ozlem Ergun, Northeastern University, Boston, MA, 2115, United States TC05 CC Ballroom E / Virtual Theater 5 Hybrid Getting Started in Public Sector Operations Research II Sponsored: Public Sector OR Sponsored Session Chair: Andrew C. Trapp, Worcester Polytechnic Institute, Worcester, MA, 01609-2247, United States 1 - Getting Started in Public Sector Operations Research II Andrew C. Trapp, Worcester Polytechnic Institute, Worcester, MA, 01609-2247, United States Public sector operations research is dedicated to decision problems with outcomes that can impact the public / society at large. Such problems often involve complex situations, uncertainty, and multiple stakeholders with differing and potentially conflicting objectives. This panel features speakers with complementary expertise in public sector operations research, who will discuss how to get started in this broad and impactful domain. Panelists will briefly describe their own research, and discussion will proceed to a moderated question and answer session. Questions from the audience are welcomed. 2 - Panelist Feyza G. Sahinyazan, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada 3 - Panelist Karen Smilowitz, Northwestern University, Evanston, IL, 60208- 0834, United States

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