Found 4 article(s) for author 'Scott Duke Kominers'

Collusion in Brokered Markets

Collusion in Brokered Markets. Scott Duke Kominers, September 7, 2019, Paper, “The U.S. residential real estate agency market presents a puzzle for economic theory: commissions on real estate transactions have remained constant and high for decades even though agent entry is frequent and agents’ costs of providing service are low. We model the real estate agency market, and other brokered markets, via repeated extensive form games; in our game, brokers first post prices for customers and then choose which agents on the other side of the market to work with. We show that prices appreciably higher than the competitive prices can be sustained (for a fixed discount factor) regardless of the number of brokers; this is done through strategies that condition willingness to transact with each broker on that broker’s initial posted prices. Our results can thus rationalize why brokered markets exhibit pricing high above marginal cost despite fierce competition for customers; moreover, our model can help explain why agents and platforms who have tried to reduce commissions have had trouble entering the market.Link

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Respect for Improvements and Comparative Statics in Matching Markets

Respect for Improvements and Comparative Statics in Matching Markets. Scott Duke Kominers, August 21, 2019, Paper, “One of the oldest results in the theory of two-sided matching is the entry comparative static, which shows that under the Gale–Shapley deferred acceptance algorithm, adding a new agent to one side of the market makes all the agents on the other side weakly better off. Here, we give a new proof of the entry comparative static, by way of a well-known property of deferred acceptance called respect for improvements. Our argument extends to yield comparative static results in more general settings, such as the matching with slot-specific preferences framework.Link

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A Compact, Logical Approach to Large-Market Analysis

A Compact, Logical Approach to Large-Market Analysis. Scott Duke Kominers, June 26, 2019, Paper, “In game theory, we often use infinite models to represent “limit” settings, such as markets with a large number of agents or games with a long time horizon. Yet many game-theoretic models incorporate finiteness assumptions that, while introduced for simplicity, play a real role in the analysis. Here, we show how to extend key results from (finite) models of matching, games on graphs, and trading networks to infinite models by way of Logical Compactness, a core result from Propositional Logic. Using Compactness, we prove the existence of man-optimal stable matchings in infinite economies, as well as strategy-proofness of the man-optimal stable matching mechanism. We then use Compactness to eliminate the need for a finite start time in a dynamic matching model. Finally, we use Compactness to prove the existence of both Nash equilibria in infinite games on graphs and Walrasian equilibria in infinite trading networks.Link

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Building a Nonprofit Marketplace to Feed America

Building a Nonprofit Marketplace to Feed America. Scott Duke Kominers, November 20, 2018, Audio, “Feeding America is the third largest nonprofit in the United States, managing a network of more than 200 food banks nationwide. Harvard Business School professor Scott Duke Kominers and Chicago Booth School of Business professor Canice Prendergast discuss how the organization designed a marketplace that was efficient and fair for all participants.Link

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