Applications: AI, digital platforms, supply chains, social enterprises, agriculture
Methodologies: game theory, behavioral experiments
RESEARCH
Ongoing Projects
[1] Human-AI Collaboration in Crowdsourcing (with Fan, X. and Wu, Q.). Target Journal: Management Science.
Working Papers under Review
[2] Mergers of Consumer Cooperatives (with Khorasani, S.). Available at https://papers.ssrn.com/sol3/papers.cfm?abstract_id=5016968
Under 2nd round review at M&SOM after a major revision.
Accepted for presentation at M&SOM Supply Chain SIG.
Appeared in the SSRN top ten download list five times.
[3] An Experimental Analysis of Participation Restriction and Visibility in Parallel Innovation Contests (with Kızılyıldırım, R., Kremer, M., and Korpeoglu, E.). Available at https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4256134
Received a reject and resubmit from M&SOM.
Third prize in the POMS College of Behavior in OM Junior Scholar Paper Competition, 2024.
[4] Solver Capacity Utilization and Allocation on Crowdsourcing Platforms: An Experimental Study (with Kızılyıldırım, R., Kremer, M., and Korpeoglu, E.). Available at https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4937154
Received a major revision from M&SOM.
Finalist in the POMS College of PITM Best Student Paper Competition, 2025.
Appeared in the SSRN top ten download list twice.
Publications
[5] Implications of Team Submissions in Open Innovation Contests (with Tang, C. and Candoğan, S. T.). IMA Journal of Management Mathematics 2025, 36(1): 1-19 [invited & lead article].
Winner award in the INFORMS Technology, Innovation Management, and Entrepreneurship Section (TIMES) Best Working Paper Competition, 2020.
Appeared in the SSRN top ten download list twice.
[6] Should an Incumbent Store Deter Entry of a Socially Responsible Retailer? (with Tang, C., Yu, J. J., and Korpeoglu, E.). Production and Operations Management 2024, 33(1): 282-302.
Appeared in the SSRN top ten download list five times.
Covered by UCLA Anderson Review.
[7] Parallel Innovation Contests (with Hafalır, I. E. and Korpeoglu, E.). Operations Research 2022, 70(3): 1506-1530.
Runner-up award in the INFORMS TIMES Best Working Paper Competition, 2018.
Selected as the paper of the month by INFORMS TIMES.
[8] Optimal Duration of Innovation Contests (with Candoğan, S. T. and Korpeoglu, E.). Manufacturing and Service Operations Management 2021, 23(3): 657-675.
Selected as the paper of the month by INFORMS TIMES.
[9] Supply Chain Competition: A Market Game Approach (with Cho, S. H. and Korpeoglu, E., first author). Management Science 2020, 66(12): 5648-5664.
Adopted as course content at INSEAD.
Covered by Tepper School of Business newspaper.
[10] Innovative Online Platforms: Research Opportunities (with Tang, C., Dai, T., Şahin, Ö., Chen, Y. J., Korpeoglu, E., and Xiao, S.). Manufacturing and Service Operations Management 2020, 22(3): 430-445 [lead article].
Adopted as course content at London Business School, Johns Hopkins University, University of California at Los Angeles, University College London, and Eindhoven University of Technology.
[11] Allocation of an Indivisible Object on the Full Preference Domain: Axiomatic Characterizations. Economic Theory (Bulletin) 2018, 6(1): 41-53 [single-authored article].
[12] A Theory of Managerial Compensation and Taxation with Endogenous Risk (with Spear, S.). Economic Theory (Bulletin) 2018, 6(1): 81-100.
[13] Price Stickiness and Markup Variations in Market Games (with Spear, S. and Chen, G.). Journal of Mathematical Economics 2017, 72: 95-103.
AWARDS AND GRANTS
Finalist, POMS College of PITM Best Student Paper Competition for 2025
“Solver Capacity Utilization and Allocation on Crowdsourcing Platforms: An Experimental Study”
Distinguished Service Award, INFORMS TIMES 2024
Third prize, POMS College of Behavior in OM Junior Scholar Paper Competition for 2024
“An Experimental Analysis of Parallel Innovation Contests”
Research Excellence Award, Eindhoven University of Technology 2022
Research Excellence Award, Eindhoven University of Technology 2021
Irene Curie Fellowship, 100,000 euros research grant, Eindhoven University of Technology 2020
Winner award, INFORMS TIMES Best Working Paper Competition for 2020
“Team Collaboration in Innovation Contests”
Research Excellence Award, Eindhoven University of Technology 2020
Runner-up award, INFORMS TIMES Best Working Paper Competition for 2018
“Parallel Innovation Contests”
Provost Fellowship, Carnegie Mellon University 2014
William L. Mellon Fellowship, Carnegie Mellon University 2009 – 2012
ABSTRACTS OF WORKING PAPERS AND PUBLICATIONS
Abstract: Consumer cooperatives are consumer-owned and managed enterprises that aim to achieve buyer power and maximize their members' welfare. Recently, several cooperatives in major economies, such as the United Kingdom (UK), Italy, and Switzerland, have merged to increase their buyer power and provide lower prices for their members. We seek to understand how these mergers affect market outcomes and consumer welfare. We build a game-theoretic model of a two-tier supply chain where multiple consumer cooperatives procure a product from a market on behalf of their member consumers. Multiple suppliers produce for this market and can increase their supply by incurring a scale-up cost. We show that mergers of cooperatives reduce the wholesale price, as intended. This enables consumers to allocate more of their income to purchasing other goods, which improves consumer welfare. However, the lower price also induces suppliers to reduce their production quantities, thereby causing each consumer to receive less of the supplied product, which reduces consumer welfare. We find that this underproduction is even more pronounced in industries with low scale-up costs. Thus, we show that mergers harm all consumers when the pre-merger number of cooperatives or the production scale-up cost is below a certain threshold. Otherwise, mergers benefit all consumers. We expand our results by considering horizontally and vertically differentiated cooperatives and show that our main results are robust. We also show that greater differentiation among cooperatives increases the benefit of mergers. Mergers of cooperatives make a nuanced impact on consumer welfare due to their effect on wholesale prices and production incentives. Policymakers should maintain healthy competition among cooperatives to maximize consumer welfare, especially in markets with low production scale-up costs.
Team Collaboration in Innovation Contests
Abstract: In an innovation contest, an organizer elicits solutions to an innovation-related problem from a group of (external) solvers. Although solvers are capable of developing solutions individually and making individual submissions, they may collaborate as teams and make team submissions when encouraged by the organizer. Motivated by different policies adopted on various crowdsourcing platforms (e.g., Wazoku, Topcoder, and 99designs), we identify conditions under which the organizer can benefit from encouraging team submissions. We build a game-theoretic model of an innovation contest where solvers make either individual or team submissions. The quality of a submitted solution depends on the effort(s) of the solver(s) working on it and whether it is easy to decompose the problem to be tackled by different solvers submitting as a team. The quality is also subject to an output uncertainty, the level of which increases with the novelty of solutions the organizer seeks. We show that given a nondecomposable problem, an organizer benefits from team submissions when seeking high-novelty solutions (e.g., system design challenges at Wazoku) but not when seeking low-novelty solutions (e.g., logo design challenges at 99designs). We further show that when the organizer seeks (low- or high-novelty) solutions to a decomposable problem (e.g., software challenges at Topcoder), the organizer can only benefit from team submissions under certain conditions. We show the innovation-contest organizer should encourage team submissions when seeking high-novelty solutions to a nondecomposable problem or when seeking low-novelty solutions to a relatively difficult decomposable problem where solver effort is costly.
Solver Capacity Utilization and Allocation on Crowdsourcing Platforms: An Experimental Study
We study innovation contests on crowdsourcing platforms that seek solutions to a set of problems from solvers who face capacity constraints in their solution-development efforts due to limited (financial, time, cognitive) resources. We analyze how solvers utilize their limited capacity and allocate it when competing in multiple contests by considering the moderating effects of solver uncertainty and platform growth. We build contest theory based on a game-theoretic model where a solver's likelihood of winning a contest is determined by the quality of her solution, which improves with her effort and is also influenced by some output uncertainty. We show that solvers increase their capacity utilization when they face lower uncertainty or compete in a larger number of contests. Furthermore, when competing in multiple contests, solvers allocate their capacity evenly across all contests. More importantly, platform growth can improve the per-contest outcome if and only if the solver uncertainty is above a certain threshold. We test these theoretical predictions with controlled laboratory experiments by varying uncertainty levels and the number of contests. Our experimental findings show that solvers utilize less capacity than predicted in all treatments, but they utilize capacity better and allocate it unevenly in a multi-contest setting. Because of these effects, the per-contest outcome is better in a multi-contest setting than in a single-contest setting, even when theory predicts equal outcomes.
An Experimental Analysis of Participation Restriction and Visibility in Parallel Innovation Contests
Abstract: We study parallel innovation contests that seek solutions from independent solvers. We analyze whether each solver should be restricted to participating in a single “exclusive” contest and, when restricted, whether the number of solvers that enter each contest should be “visible” or “opaque” to solvers. We build contest theory based on a game-theoretic model and test it with controlled laboratory experiments. In the model, we study two innovation contests with asymmetric awards. Solvers generate solutions in the contests they enter by exerting costly effort, and their solution quality is subject to uncertainty. We consider three formats based on participation restrictions and visibility. Our theory predicts that the average contest profit is always the lowest in the exclusive-opaque format because solvers often lean towards one contest too much. Making participation visible can remedy this issue, and hence, the exclusive-visible format can yield the highest average profit when solver uncertainty is low. Otherwise, a non-exclusive format that does not restrict participation is optimal. In our experimental data, while other formats perform consistently with our theory, the exclusive-visible format performs significantly worse than theoretical predictions. Our main result (and key managerial insight) is that non-exclusive contests are more attractive to organizers even when theory suggests otherwise because the participation visibility does not make the intended positive impact on exclusive contests. We link this result to behavioral tendencies that affect solvers’ contest choices, thereby hindering the average profit in exclusive contests with visible participation.
Should an Incumbent Store Deter Entry of a Socially Responsible Retailer?
Abstract: As consumers become more conscious about social issues, they gain an additional "social benefit" when purchasing from a socially responsible retailer (or brand). This trend has motivated more socially responsible retailers (or brands) to enter the market with a "pre-commitment" to donate a certain proportion of their (A) profits or (B) revenues for social causes. In this paper, we present a game-theoretic model where a socially responsible retailer enters the market with an incumbent for-profit retailer and heterogeneous consumers. We examine the socially responsible retailer's pricing strategy and entry conditions, the impact of the socially responsible retailer's entry on the incumbent retailer's profit, and the conditions under which the incumbent retailer should deter (or tolerate) the socially responsible retailer's entry. Our equilibrium analysis generates the following insights. First, even if the incumbent retailer can profitably deter the socially responsible retailer's entry, the incumbent retailer can be better off tolerating it under certain conditions. Second, somewhat interestingly, the incumbent retailer is more likely to deter the type (B) retailer's entry even though such entry is less detrimental to the incumbent retailer.
Abstract: We study multiple parallel contests where contest organizers elicit solutions to innovation-related problems from a set of solvers. Each solver may participate in multiple contests and exert effort to improve her solution for each contest she enters, but the quality of her solution in each contest also depends on an output uncertainty. We first analyze whether an organizer's profit can be improved by discouraging solvers from participating in multiple contests. We show, interestingly, that organizers benefit from solvers participating in multiple contests when the solver's output uncertainty in these contests is sufficiently large. A managerial insight from this result is that when all organizers are eliciting innovative solutions rather than low-novelty solutions, they may benefit from solvers participating in multiple contests. We also show that organizers' average profit increases when solvers participate in multiple contests even when some contests seek low-novelty solutions, as long as other contests seek cutting-edge innovation. We further show that an organizer's profit is unimodal in the number of contests, and the optimal number of contests increases with the solver's output uncertainty. This finding may explain why many organizations run multiple contests in practice, and it suggests running a larger number of contests when the majority of these organizations are seeking innovative solutions rather than low-novelty solutions.
Optimal Duration of Innovation Contests
Abstract: We study the duration and the award scheme of an innovation contest where an organizer elicits solutions to an innovation-related problem from a group of agents. We use a game-theoretic model where the organizer decides on the contest duration and the award scheme while each agent decides on her participation, and determines her effort over the contest duration by considering potential changes in her productivity over time. The quality of an agent’s solution improves with her effort, but it is also subject to an output uncertainty. We show that the optimal contest duration increases as the relative impact of the agent uncertainty on her output increases, and it decreases if the agent productivity increases over time. These results suggest that the optimal contest duration increases with the novelty or sophistication of solutions that the organizer seeks, and it decreases when the organizer can offer support tools that can increase the agent productivity over time. More interestingly, we characterize an optimal award scheme, and show that giving multiple (almost always) unequal awards is optimal when the organizer’s urgency in obtaining solutions is below a certain threshold. We also show that this threshold is larger when the agent productivity increases over time. These results help explain why many contests on crowdsourcing platforms give multiple unequal awards. Finally, consistent with empirical findings, we show that there is a positive correlation between the optimal contest duration and the optimal total award.
Abstract: We study supply chains where multiple suppliers sell to multiple retailers through a wholesale market. In practice, we often observe that both suppliers and retailers tend to influence the wholesale market price retailers pay to suppliers. However, existing models of supply chain competition do not capture retailers' influence on the wholesale price (i.e., buyer power), and show that the wholesale price and the order quantity per retailer do not change with the number of retailers. To overcome this limitation, we develop a competition model based on the market-game mechanism in which the wholesale price is determined based on both suppliers' and retailers' decisions. When taking into account retailers' buyer power, we obtain the result that is consistent with the observed practice: as the number of retailers increases, each retailer's buyer power decreases, and each retailer is willing to pay more for her order, so the wholesale price increases. In this case, supply chain expansion to include more retailers (or suppliers) turns out to be more beneficial in terms of supply chain efficiency than what the prior literature shows without considering buyer power. Finally, we analyze the integration of two local supply chains, and show that, although the profit of the integrated supply chain is greater than the sum of total profits of local supply chains, integration may reduce the total profit of firms in a retailer-oriented supply chain that has more retailers than suppliers.
Abstract: Economic growth in many countries is increasingly driven by successful startups that operate as online platforms. These success stories have motivated us to define and classify various online platforms according to their business models. This study discusses strategic and operational issues arising from five types of online platforms (resource sharing, matching, crowdsourcing, review, and crowdfunding) and presents some research opportunities for operations management scholars to explore.
Abstract: I study the problem of allocating an indivisible object to one of several agents on the full preference domain when monetary transfers are not allowed. My main requirement is strategy-proofness. The other properties we seek are Pareto optimality, non-dictatorship, and non-bossiness. We provide characterizations of strategy-proof rules that satisfy Pareto optimality and non-bossiness, non-dictatorship and non-bossiness, and Pareto optimality and non-dictatorship. As a consequence of these characterizations, I show that a strategy-proof rule cannot satisfy Pareto optimality, non-dictatorship, and non-bossiness simultaneously.
Abstract: We study the impact of endogenous shocks driven by collective actions of managers. We analyze how such endogenous shocks impact social welfare by employing an overlapping-generations model. We first prove that the competitive equilibrium allocation is suboptimal because of the externalities in managers' wages and in equity market. We establish that a socially optimal allocation can be achieved if the planner imposes wage taxes (or subsidies) on managers and equity taxes. Our results help provide an alternative explanation as to why managers are compensated and taxed differently than other workers. We then extend the model by incorporating unobservable actions for managers and show that a second-best allocation can be implemented if the planner imposes equity taxes.
Abstract: In this paper, we show that the Shapley-Shubik market game model with production naturally generates an equilibration mechanism that can accommodate price stickiness arising from strategic interactions of firms. Unlike New Keynesian models that show similar price stickiness results, the market game model does not require enforcing menu costs or other additional restraints on price adjustment mechanisms in order to generate price stickiness. As such, we suggest that the market game model can provide a good micro-foundation for macroeconomic analysis. We then explicitly show the relationship between a typical firm's markup of price over marginal cost and its market share.