Advanced Search
MyIDEAS: Login

A Framework for Dynamic Oligopoly in Concentrated Industries

Contents:

Author Info

  • Vivek Farias

    (MIT)

  • Bar Ifrach

    (Columbia Business School)

  • Gabriel Weintraub

    (Columbia University)

Registered author(s):

    Abstract

    We consider dynamic oligopoly models in the spirit of Ericson and Pakes (1995). We introduce a new computationally tractable model for industries with a few dominant firms and many fringe firms. This is a prevalent market structure in consumer and industrial goods. In our model, firms keep track of the detailed state of dominant firms and of few moments of the distribution that describes the states of fringe firms. Based on this idea we introduce a new equilibrium concept that we call moment-based Markov equilibrium (MME). MME is behaviorally appealing and computationally tractable. However, MME can suffer from an important pitfall. Because moments may not summarize all payoff relevant information, MME strategies may not be optimal. We propose different approaches to overcome this difficulty with varying degrees of restrictions on the model primitives and strategies. Our first approach introduces models for which moments summarize all payoff relevant history and therefore for which MME strategies are optimal. The second approach restrict fringe firm strategies so that again moments become sufficient statistics. The third approach does not impose such restrictions, but introduces a computational error bound to asses the degree of sub-optimality of MME strategies. This bound allows to evaluate whether a finer state aggregation is necessary, for example by adding more moments. We provide computational experiments to show that our algorithms and error bound work well in practice for important classes of models. We also show that, cumulatively, fringe firms discipline dominant firms to behave more competitively, and that ignoring fringe firms in counterfactual analysis may lead to incorrect conclusions. Our model significantly extends the class of dynamic oligopoly models that can be studied computationally. In addition, our methods can also be used to improve approximations in other contexts such as dynamic industry models with an infinite number of heterogeneous firms and an aggregate shock; stochastic growth models in the spirit of Krusell and Smith (1998); and dynamic models with forward-looking consumers.

    Download Info

    If you experience problems downloading a file, check if you have the proper application to view it first. In case of further problems read the IDEAS help page. Note that these files are not on the IDEAS site. Please be patient as the files may be large.
    File URL: http://www.economicdynamics.org/meetpapers/2012/paper_505.pdf
    Download Restriction: no

    Bibliographic Info

    Paper provided by Society for Economic Dynamics in its series 2012 Meeting Papers with number 505.

    as in new window
    Length:
    Date of creation: 2012
    Date of revision:
    Handle: RePEc:red:sed012:505

    Contact details of provider:
    Postal: Society for Economic Dynamics Christian Zimmermann Economic Research Federal Reserve Bank of St. Louis PO Box 442 St. Louis MO 63166-0442 USA
    Fax: 1-314-444-8731
    Email:
    Web page: http://www.EconomicDynamics.org/society.htm
    More information through EDIRC

    Related research

    Keywords:

    This paper has been announced in the following NEP Reports:

    References

    No references listed on IDEAS
    You can help add them by filling out this form.

    Citations

    Lists

    This item is not listed on Wikipedia, on a reading list or among the top items on IDEAS.

    Statistics

    Access and download statistics

    Corrections

    When requesting a correction, please mention this item's handle: RePEc:red:sed012:505. 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: (Christian Zimmermann).

    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 references are entirely missing, you can add them using this form.

    If the full references list an item that is present in RePEc, but the system did not link 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 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.