IDEAS home Printed from
   My bibliography  Save this paper

A Complete Characterization of Equilibria in a Common Agency Screening Game


  • Martimort, David
  • Semenov, Aggey
  • Stole, Lars


We characterize the complete set of equilibrium allocations to an intrinsic common agency screening game as the set of solutions to self-generating optimization programs. We provide a complete characterization of equilibrium outcomes for regular environments by relying on techniques developed elsewhere for aggregate games and for the mechanism design delegation literature. The set of equilibria include those with non-differentiable payoffs and discontinuous choices, as well as equilibria that are smooth and continuous in types. We identify one equilibrium, the maximal equilibrium, which is the unique solution to a self-generating optimization program with the largest (or “maximal”) domain, and the only equilibrium that is supported with bi-conjugate (i.e., least-concave) tariffs. The maximal equilibrium exhibits a n-fold distortion caused by each of the n principal’s non-cooperative behavior in over- harvesting the agent’s information rent. Furthermore, in any equilibrium, over any interval of types in which there is full separation, the agent’s equilibrium action corresponds to the allocation in the maximal equilibrium. Under mild conditions, the maximal equilibrium maximizes the agent’s information rent within the class of equilibrium allocations. When the principals’ most-preferred equilibrium allocation differs from the maximal equilibrium, we demonstrate that the agent’s choice function exhibits an interval of bunching over the worst agent types, and elsewhere corresponds with the maximal allocation. The optimal region of bunching trades off the principals’ desire to constrain inefficient n-fold marginalizations of the agent’s rent against the inefficiency of pooling agent types.

Suggested Citation

  • Martimort, David & Semenov, Aggey & Stole, Lars, 2017. "A Complete Characterization of Equilibria in a Common Agency Screening Game," MPRA Paper 80870, University Library of Munich, Germany.
  • Handle: RePEc:pra:mprapa:80870

    Download full text from publisher

    File URL:
    File Function: original version
    Download Restriction: no

    References listed on IDEAS

    1. Mark Bagnoli & Ted Bergstrom, 2005. "Log-concave probability and its applications," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 26(2), pages 445-469, August.
    2. Ricardo Alonso & Niko Matouschek, 2008. "Optimal Delegation," Review of Economic Studies, Oxford University Press, vol. 75(1), pages 259-293.
    3. Martimort, David & Semenov, Aggey, 2008. "Ideological uncertainty and lobbying competition," Journal of Public Economics, Elsevier, vol. 92(3-4), pages 456-481, April.
    4. Giacomo Calzolari & Vincenzo Denicol?, 2013. "Competition with Exclusive Contracts and Market-Share Discounts," American Economic Review, American Economic Association, vol. 103(6), pages 2384-2411, October.
    5. Laussel, Didier & Le Breton, Michel, 2001. "Conflict and Cooperation: The Structure of Equilibrium Payoffs in Common Agency," Journal of Economic Theory, Elsevier, vol. 100(1), pages 93-128, September.
    6. Peters, Michael, 2001. "Common Agency and the Revelation Principle," Econometrica, Econometric Society, vol. 69(5), pages 1349-1372, September.
    7. David Martimort & Lars Stole, 2002. "The Revelation and Delegation Principles in Common Agency Games," Econometrica, Econometric Society, vol. 70(4), pages 1659-1673, July.
    8. Martimort, David & Stole, Lars, 2012. "Representing equilibrium aggregates in aggregate games with applications to common agency," Games and Economic Behavior, Elsevier, vol. 76(2), pages 753-772.
    9. Szentes, Balázs, 2015. "Contractible contracts in common agency problems," LSE Research Online Documents on Economics 66071, London School of Economics and Political Science, LSE Library.
    10. Myerson, Roger B., 1982. "Optimal coordination mechanisms in generalized principal-agent problems," Journal of Mathematical Economics, Elsevier, vol. 10(1), pages 67-81, June.
    11. Hoernig Steffen & Valletti Tommaso M., 2011. "When Two-Part Tariffs are Not Enough: Mixing with Nonlinear Pricing," The B.E. Journal of Theoretical Economics, De Gruyter, vol. 11(1), pages 1-20, October.
    12. Balázs Szentes, 2015. "Contractible Contracts in Common Agency Problems," Review of Economic Studies, Oxford University Press, vol. 82(1), pages 391-422.
    13. Laussel, Didier & Le Breton, Michel, 1998. "Efficient Private Production of Public Goods under Common Agency," Games and Economic Behavior, Elsevier, vol. 25(2), pages 194-218, November.
    14. Nahum D. Melumad & Toshiyuki Shibano, 1991. "Communication in Settings with No. Transfers," RAND Journal of Economics, The RAND Corporation, vol. 22(2), pages 173-198, Summer.
    15. Paul Milgrom & Ilya Segal, 2002. "Envelope Theorems for Arbitrary Choice Sets," Econometrica, Econometric Society, vol. 70(2), pages 583-601, March.
    16. Chiesa, Gabriella & Denicolò, Vincenzo, 2009. "Trading with a common agent under complete information: A characterization of Nash equilibria," Journal of Economic Theory, Elsevier, vol. 144(1), pages 296-311, January.
    17. Carlier, Guillaume, 2001. "A general existence result for the principal-agent problem with adverse selection," Journal of Mathematical Economics, Elsevier, vol. 35(1), pages 129-150, February.
    18. Alonso, Ricardo & Matouschek, Niko, 2008. "Optimal delegation," LSE Research Online Documents on Economics 58665, London School of Economics and Political Science, LSE Library.
    19. Martimort, David & Stole, Lars, 2015. "Menu Auctions and Influence Games with Private Information," MPRA Paper 62388, University Library of Munich, Germany.
    20. Martimort, David & Semenov, Aggey, 2006. "Continuity in mechanism design without transfers," Economics Letters, Elsevier, vol. 93(2), pages 182-189, November.
    21. Manuel Amador & Kyle Bagwell, 2013. "The Theory of Optimal Delegation With an Application to Tariff Caps," Econometrica, Econometric Society, vol. 81(4), pages 1541-1599, July.
    22. Rochet, Jean-Charles, 1987. "A necessary and sufficient condition for rationalizability in a quasi-linear context," Journal of Mathematical Economics, Elsevier, vol. 16(2), pages 191-200, April.
    Full references (including those not matched with items on IDEAS)

    More about this item


    Intrinsic common agency; aggregate games; mechanism design for delegated decision-making; duality; equilibrium selection.;

    JEL classification:

    • D82 - Microeconomics - - Information, Knowledge, and Uncertainty - - - Asymmetric and Private Information; Mechanism Design
    • D86 - Microeconomics - - Information, Knowledge, and Uncertainty - - - Economics of Contract Law

    NEP fields

    This paper has been announced in the following NEP Reports:


    Access and download statistics


    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:pra:mprapa:80870. See general information about how to correct material in RePEc.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Joachim Winter). General contact details of provider: .

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service hosted by the Research Division of the Federal Reserve Bank of St. Louis . RePEc uses bibliographic data supplied by the respective publishers.