Abstract
In this paper, we provide a result that shows existence and uniqueness of Nash equilibrium in cases in which existing methods are problematic. This result is based on a theorem by Kellogg (Proc Am Math Soc 60:207–210, 1976) that provides conditions for the existence of a unique fixed point. We apply it to the simple logit discrete choice model and the CES representative consumer model, where asymmetric cost firms produce multiple vertically and horizontally differentiated products and compete in prices.
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Anderson S.P., de Palma A.: Multiproduct firms: a nested logit approach. J Ind Econ 40, 261–276 (1992)
Anderson S.P., de Palma A., Thisse J.-F.: Discrete Choice Theory of Product Differentiation. MIT Press, Cambridge (1992)
Bagnoli M., Bergstrom T.: Log-concave probability and its applications. Econ Theory 26, 445–469 (2005)
Berry S., Levinsohn J., Pakes A.: Automobile prices in market equilibrium. Econometrica 63, 841–890 (1995)
Berry S., Linton O.B., Pakes A.: Limit theorems for estimating the parameters of differentiated product demand systems. Rev Econ Stud 71, 613–654 (2004)
Caplin A., Nalebuff B.: Aggregation and imperfect competition: on the existence of equilibrium. Econometrica 59, 25–59 (1991)
Champsaur P., Rochet J.-C.: Multiproduct duopolists. Econometrica 57, 533–557 (1989)
Dierker E. : Competition for customers. In: Cornet, B., d’Aspremont, C., Mas-Colell, A. (eds) Equilibrium Theory and Applications., pp. 383–402. Cambridge University Press, Cambridge (1991)
Dixit A., Stiglitz J.E.: Monopolistic competition and optimal product diversity. Am Econ Rev 67, 297–308 (1977)
Dhrymes P.J.: Mathematics for Econometrics. Springer, New York (1984)
Feenstra R.C., Levinsohn J.A.: Estimating markups and market conduct with multidimensional product attributes. Rev Econ Stud 62, 19–52 (1995)
Gale D., Nikaido H.: The Jacobian matrix and global univalence of mapping. Math Ann 159, 81–93 (1965)
Hanson W., Martin K.: Optimizing multinomial logit profit functions. Manage Sci 42, 992–1003 (1996)
Johnson J., Myatt D.: Multiproduct quality competition: fighting brands and product line pruning. Am Econ Rev 93, 748–774 (2003)
Kellogg R.B.: Uniqueness in the Schauder fixed point theorem. Proc Am Math Soc 60, 207–210 (1976)
Mañez, J.A., Waterson, M.: Multiproduct firms and product differentiation: a survey, University of Warwick Working paper no. 594 (2001)
Milnor J.: Topology from the Differentiable Viewpoint. University Press of Virginia, Charlottesville (1965)
Mizuno T.: On the existence of a unique price equilibrium for models of product differentiation. Int J Ind Organ 21, 761–793 (2003)
Nevo A.: Measuring market power in the ready-to-eat cereal industry. Econometrica 69, 307–342 (2001)
Peitz M.: Aggregation in a model of price competition. J Econ Theory 90, 1–38 (2000)
Peitz M.: Price equilibrium in address models of product differentiation: unit-elastic demand. Econ Theory 20, 849–860 (2002)
Sándor, Z.: Computation, efficiency and endogeneity in discrete choice models, PhD Thesis, University of Groningen (2001)
Spence M.: Product selection, fixed costs, and monopolistic competition. Rev Econ Stud 43, 217–235 (1976)
Tirole J.: The Theory of Industrial Organization. MIT Press, Cambridge (1988)
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The authors thank Mark Armstrong, José Luis Moraga-González, Frank Verboven and anonymous referees for helpful remarks.
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Konovalov, A., Sándor, Z. On price equilibrium with multi-product firms. Econ Theory 44, 271–292 (2010). https://doi.org/10.1007/s00199-009-0486-5
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DOI: https://doi.org/10.1007/s00199-009-0486-5