Informs 2015

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INFORMS Philadelphia – 2015
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4 - Creativity under Fire: The Effects of Competition on
Creative Production
Daniel P. Gross, Post-doctoral Fellow, NBER/Harvard Business
School, Soldiers Field Road, Boston, MA, 02163,
United States of America,
This paper studies the incentive effects of competition on individuals’ creative
production. Using a sample of commercial logo design competitions, and a novel,
content-based measure of originality, I find that competition has an inverted-U
effect on creativity. The results reconcile conflicting evidence from an extensive
literature on the effects of competition on innovation, with implications for R&D
policy, competition policy, and organizations in creative or research industries.
TC10
10-Room 310, Marriott
e-Media and Health Care Practices
Sponsor: E-Business
Sponsored Session
Chair: Harpreet Singh, University of Texas at Dallas, 800 West Campbell
Road, Richardson, United States of America,
1 - Does the Adoption of EMR Systems Inflate
Medicare Reimbursements?
Kartik Ganju, Temple University, Fox School of Business,
Philadelphia, PA, United States of America,
, Hilal Atasoy, Paul Pavlou
We study if the adoption of the CPOE system is associated with an increase in the
complexity of the case mix that hospitals report (upcoding). We use the staggered
roll-out of the Recovery Audit Program as a natural experiment to assess the
impact of the adoption of the CPOE systems on the case mix that a hospital
reports. We find that the adoption of CPOE systems is associated with an increase
in the reported case mix of hospitals but the Audit program has had an effect on
reducing this.
2 - Profit Complementarities in Adopting Electronic Medical
Records by U.S. Hospitals
Jianjing Lin, University of Arizona, 1130 E Helen St, Tucson, AZ,
85719, United States of America,
This paper tries to examine by how much hospitals’ profit can be increased if they
choose the locally market-leading vendor. Using a nationwide sample of U.S.
hospitals from 2006 to 2010, I construct a dynamic oligopoly model and recover
the model primitives with a classic approach in Economics. I find hospitals gain
significant benefits from choosing the local leader and if hospitals were
incentivized to choose such a technology, it would help improve the market
coordination substantially.
3 - Get in Shape with Online Friends: Obesity and Social Networks
Behnaz Bojd, University of Washington, Seattle WA,
United States of America, Yong Tan, Lu Yan
Obesity is one of the most prevalent health problems in the world. Individuals
suffering from this condition may use online social networks to get medical
information or emotional support. In this study, we examine the effects of online
social networking on individual weight-loss behavior, using a unique data set
from a platform where people can track their weight, seek food and fitness
information, share experiences, find buddies, and participate in different
challenges.
4 - Digital Word-of-mouth and Consumer Demand for Credence
Services: Evidence from a Natural Experiment
Aishwarya Deep Shukla, PhD Student, University of Maryland,
College Park, 3330C R H Smith School of Business, College Park,
20742, United States of America, ,
Ritu Agarwal, Gordon Gao
This paper examines the impact of online word-of-mouth on consumer demand
for credence services. We utilize a natural experiment setting from one of the
largest physician appointment booking platforms in India, when the website
made the doctor “recommendations” visible to users. In addition, we explore the
long term effect of this visibility of recommendations in the context of matching
the severity of the patient to the skill of the doctor.
TC11
11-Franklin 1, Marriott
Advances in Discrete Optimization
Sponsor: Optimization/Integer and Discrete Optimization
Sponsored Session
Chair: Gustavo Angulo, Assistant Professor, Pontificia Universidad
Catolica de Chile, Vicuña Mackenna 4860, Macul, Santiago, 7820436,
Chile,
1 - Optimization over Structured Subsets of Positive Semidefinite
Matrices via Column Generation
Sanjeeb Dash, IBM Research, Yorktown Heights, NY,
United States of America, ,
Amir Ali Ahmadi, Georgina Hall
We describe LP and SOCP algorithms that optimize over some structured subsets
of the cone of positive semidefinite matrices (PSD cone) in an iterative fashion via
column generation, starting with an initial linear approximation of the PSD cone
given by Ahmadi and Majumdar (2014). We apply our techniques to sum-of-
squares programming for nonconvex polynomial optimization problems, and to a
copositive programming relaxation of the stable set problem.
2 - Cutting Planes from Extended LP Formulations
Merve Bodur, UW-Madison, 1513 University Avenue,
Madison, WI, 53706, United States of America,
, Sanjeeb Dash, Oktay Gunluk
For mixed-integer sets, we study extended formulations of their LP relaxations.
We show that applying split cuts to such extended formulations can be more
effective than applying split cuts to the original formulation. For any 0-1 mixed-
integer set with n integer and k continuous variables, we construct an extended
formulation with 2n+k-1 variables whose split closure is integral. We extend this
to general mixed-integer sets and construct the best extended formulation with
respect to split cuts.
3 - Robust (MONOTONE) Submodular Function Maxmization
Rajan Udwani, ORC, MIT, 70 Pacific Street, 324C, Cambridge,
MA, 02139, United States of America, ,
James Orlin, Andreas Schulz
Consider two common instances of monotone submodular function maximization
with cardinality constraint, feature selection (machine learning) and sensor
placement. In both, it is often the case that out of the chosen set of features
(sensors), some may be corrupt (may fail). Thus, we would like our chosen set to
be robust to removal of some elements. We consider a previously known
formulation of this problem and give the first constant factor approximation
algorithms.
4 - On a Semicontinuous Relaxation of Fixed-charge Network
Flow Problems
Gustavo Angulo, Assistant Professor, Pontificia Universidad
Católica de Chile, Vicuña Mackenna 4860, Macul, Santiago,
7820436, Chile,
Usual formulations of fixed-charge network flow problems make use of binary
variables to indicate whether an arc is open or not, and to impose lower and
upper bounds on the flow whenever an arc is used. We propose a relaxation
where both binary and flow variables are treated as unbounded semicontinuous
variables. We derive a complete linear description of the convex hull of this
relaxation and show the tractability of the associated separation problem.
TC12
12-Franklin 2, Marriott
Optimization Integer Programming I
Contributed Session
Chair: John Chinneck, Professor, Carleton University, Systems and
Computer Engineering, 1125 Colonel By Drive, Ottawa, ON, K1S5B6,
Canada,
1 - School Districting Problem (SDP) Framed as a Spatial
Optimization Model/mixed Integer Program
Shawn Helm, Senior Manager, Portland Public Schools, 501
North Dixon Street, Portland, OR, 97227-1807, United States of
America, , Will Kearney, Sahan Dissanayake
SDPs assign neighborhoods to schools given physical, demographic, and policy
constraints. We control capacity; compactness; contiguity; amount of
demographic change. Users specify class size; grade band; neighborhood capture
assumptions; room uses; which current assignments are retained. The integrated
framework uses real GIS data from Portland Public Schools and available solvers
to identify best school-neighborhood assignments; solves model to display results
and inform boundary decisions.
TC12