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Information, market power, and price volatility
Author(s) -
Bergemann Dirk,
Heumann Tibor,
Morris Stephen
Publication year - 2021
Publication title -
the rand journal of economics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.687
H-Index - 108
eISSN - 1756-2171
pISSN - 0741-6261
DOI - 10.1111/1756-2171.12364
Subject(s) - market power , volatility (finance) , economics , private information retrieval , cournot competition , stochastic game , microeconomics , perfect information , econometrics , complete information , mathematics , monopoly , statistics
We consider demand function competition with a finite number of agents and private information. We show that any degree of market power can arise in the unique equilibrium under an information structure that is arbitrarily close to complete information. Regardless of the number of agents and the correlation of payoff shocks, market power may be arbitrarily close to zero (the competitive outcome) or arbitrarily large (so there is no trade). By contrast, price volatility is always lower than the variance of the aggregate shock across all information structures. Alternative trading mechanisms lead to very distinct bounds as a comparison with Cournot competition establishes.