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Separating complements: the effects of competition and quality leadership


The literature on the tragedy of the anticommons typically suggests that producers of complementary goods should integrate themselves. Recent decisions by the antitrust authorities seem however to indicate that there exists a tradeoff between the “tragedy” and the lack of competition characterizing an integrated market structure. In this paper we analyze such tradeoff in oligopolistic complementary markets when products are vertically differentiated. We show that quality leadership plays a crucial role. When there is a quality leader, forcing divestitures or prohibiting mergers, thus increasing competition, lowers prices and enhances consumer surplus. However, when quality leadership is shared, “disintegrating” firms may lead to higher prices. In this case, concerns about the tragedy of the anticommons are well posed in antitrust decisions.

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  • Alvisi M, Carbonara E (2010) Imperfect substitutes for perfect complements: solving the anticommons problem. Department of Economics working paper n.708/June 2010. University of Bologna

  • Alvisi M, Carbonara E, Dari-Mattiacci G, Parisi F (2009) Complementing substitutes: bundling, compatibility and entry. Amsterdam Center for Law & Economics working paper no. 2009-10

  • Buchanan J, Yoon YJ (2000) Symmetric tragedies: commons and anticommons. J Law Econ 43: 1–13

    Article  Google Scholar 

  • Casadesus-Masanell R, Nalebuff B, Yoffie D (2007) Competing complements. Harvard Business School working paper n.09-009

  • Chen MK, Nalebuff B (2006) One-way essential complements. Cowles Foundation discussion paper no.1588

  • Choi JP (2008) Mergers with bundling in complementary markets. J Ind Econ 56(3): 553–577

    Article  Google Scholar 

  • Cournot A (1838) Recherches sur les Principes Mathematiques de la Theorie des Richesses, Hachette, Paris (English translation by NT Bacon published in Economic Classics [Macmillan, 1897] and reprinted in 1960 by Augustus M. Kelly)

  • Dari-Mattiacci G, Parisi F (2007) Substituting complements. J Competition Law Econ 2(3): 333–347

    Article  Google Scholar 

  • Denicolò V (2000) Compatibility and bundling with generalist and specialist firms. J Ind Econ 48(2): 177–187

    Google Scholar 

  • Economides N (1989) Desirability of compatibility in the absence of network externalities. Am Econ Rev 79: 1165–1181

    Google Scholar 

  • Economides N, Salop SC (1992) Competition and integration among complements, and network market structure. J Ind Econ 40(1): 104–123

    Article  Google Scholar 

  • Einhorn MA (1992) Mix and match compatibility with vertical product dimension. RAND J Econ 23(4): 535–547

    Article  Google Scholar 

  • Gabszewicz JJ, Thisse JF (1979) Price competition, quality and income disparities. J Econ Theory 20: 340–359

    Article  Google Scholar 

  • Gans JS, King SP (2006) Paying for loyalty: product bundling in oligopoly. J Ind Econ 54(1): 43–62

    Article  Google Scholar 

  • Heller M (1998) The tragedy of the anticommons: property in the transition from Marx to markets. Harvard Law Review 111(3): 621–688

    Article  Google Scholar 

  • Matutes C, Regibeau P (1988) “Mix and Match”: product compatibility without network externalities. RAND J Econ 19(2): 221–233

    Article  Google Scholar 

  • Matutes C, Regibeau P (1992) Compatibility and bundling of complementary goods in a duopoly. J Ind Econ 40: 37–53

    Article  Google Scholar 

  • Motta M (2003) Competition Policy. Theory and practice. Cambridge University Press, New York

    Google Scholar 

  • Motta M, Vasconcelos H (2005) Efficiency gains and myopic antitrust authority in a dynamic merger game. Int J Ind Organ 23(9–10): 777–801

    Article  Google Scholar 

  • Nalebuff B (2004) Bundling as an entry barrier. Q J Econ 1: 159–187

    Article  Google Scholar 

  • Parisi F, Schulz N, Depoorter B (2005) Duality in property: commons and anticommons. Int Rev Law Econ 25(4): 578–591

    Article  Google Scholar 

  • Parker GG, Van Alstyne MW (2005) Two-sided network effects: a theory of information product design. Manag Sci 51(10): 1494–1504

    Article  Google Scholar 

  • Peitz M (2008) Bundling may blockade entry. Int J Ind Organ 26: 41–58

    Article  Google Scholar 

  • Shapiro C, Varian H (1999) Information rules. A strategic guide to the network economy. Harvard Business School Press, Boston

    Google Scholar 

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Correspondence to Emanuela Carbonara.

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Alvisi, M., Carbonara, E. & Parisi, F. Separating complements: the effects of competition and quality leadership. J Econ 103, 107–131 (2011).

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  • Complements
  • Anticommons
  • Competition
  • Mergers
  • Vertical differentiation

JEL Classification

  • C7
  • D42
  • D43
  • K21
  • L11
  • L12
  • L13
  • L40
  • M21