IDEAS home Printed from
   My bibliography  Save this paper

Vertical differentiation, network externalities and compatibility decisions : an alternative approach




We characterize the equilibrium of a game in vertically differentiated market which exhibits network externalities. There are two firms, an incumbent and a potential entrant. Compatibility means in our model that the inherent qualities of the goods are close enough. By choosing its quality, the entrant chooses in the same time to be compatible or not. The maximal quality difference that allows compatibility i.e. the compatibility interval is chosen by the incumbent which involves costs increasing with the width of that interval. We show that in order to have two active firms at price equilibrium, the sufficient condition on the market size of a standard vertical differentiation model remains valid under compatibility. However, an additional condition on the firms' qualities is needed under incompatibility. For a small quality segment, the incumbent can block entry choosing an empty compatibility interval. At the subgame perfect equilibrium, incompatibility prevails if the quality segment is large and the compatibility costs are high. Compatibility prevails for sufficiently large quality segments and low costs of compatibility. Finally there is no entry if the quality segment is small and the compatibility costs are high.

Suggested Citation

  • Hend Ghazzai & Rim Lahmandi-Ayed, 2006. "Vertical differentiation, network externalities and compatibility decisions : an alternative approach," Cahiers de la Maison des Sciences Economiques b06013, Université Panthéon-Sorbonne (Paris 1).
  • Handle: RePEc:mse:wpsorb:b06013

    Download full text from publisher

    File URL:
    Download Restriction: no

    Other versions of this item:

    References listed on IDEAS

    1. Baake, Pio & Boom, Anette, 2001. "Vertical product differentiation, network externalities, and compatibility decisions," International Journal of Industrial Organization, Elsevier, vol. 19(1-2), pages 267-284, January.
    2. repec:ebl:ecbull:v:12:y:2004:i:1:p:1-9 is not listed on IDEAS
    3. Jeanneret, Marie-Helene & Verdier, Thierry, 1996. "Standardization and protection in a vertical differentiation model," European Journal of Political Economy, Elsevier, vol. 12(2), pages 253-271, September.
    4. Navon, Ami & Shy, Oz & Thisse, Jacques-François, 1995. "Product Differentiation in the Presence of Positive and Negative Network Effects," CEPR Discussion Papers 1306, C.E.P.R. Discussion Papers.
    5. repec:adr:anecst:y:1998:i:49-50:p:13 is not listed on IDEAS
    6. Nicolas Jonard & Eric Schenk, 2004. "A note on compatibility and entry in a circular model of product differentiation," Economics Bulletin, AccessEcon, vol. 12(1), pages 1-9.
    Full references (including those not matched with items on IDEAS)

    More about this item


    Vertical differentiation; compatibility; network externalities.;

    JEL classification:

    • L13 - Industrial Organization - - Market Structure, Firm Strategy, and Market Performance - - - Oligopoly and Other Imperfect Markets
    • L15 - Industrial Organization - - Market Structure, Firm Strategy, and Market Performance - - - Information and Product Quality
    • D43 - Microeconomics - - Market Structure, Pricing, and Design - - - Oligopoly and Other Forms of Market Imperfection

    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:mse:wpsorb:b06013. 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: (Lucie Label). 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.