Economic Theory

, Volume 58, Issue 1, pp 125–160

Collusive communication schemes in a first-price auction

Research Article

DOI: 10.1007/s00199-013-0778-7

Cite this article as:
Āzacis, H. & Vida, P. Econ Theory (2015) 58: 125. doi:10.1007/s00199-013-0778-7


We study optimal bidder collusion in an independent private value first-price auction with two bidders and two possible valuations. There is a benevolent center that knows the bidders’ valuations and sends private signals to the bidders in order to maximize their expected payoffs. After receiving their signals, bidders compete in a standard first-price auction, that is, without side payments or bid restrictions. We find that to improve on the bidders’ payoffs, the signals must depend upon the valuations. If the bidders’ signals are restricted to be non-correlated (depend only on the opponent’s valuation), then the bidders’ payoffs are strictly higher than the larger possible set of signals. If the signals are restricted to be perfectly correlated (public), only two possible signals are needed to achieve the highest bidder payoffs. However, these payoffs can be improved upon if the two signals are allowed to be imperfectly correlated.


Bidder-optimal signal structure Bid coordination mechanism Collusion (Bayes) correlated equilibrium First-price auction  Public and private signals 

JEL Classification

D44 D82 

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  1. 1.Cardiff Business SchoolCardiff UniversityCardiffWales, UK
  2. 2.Department of EconomicsUniversity of MannheimMannheimGermany

Personalised recommendations