| Abstract: | Summary. The results previously obtained on the finiteness property in vertically differentiated markets, with cost functions having increasing or decreasing returns, are extended to a much larger class of cost functions with local properties in a vicinity of the zero output. Moreover, existence results are provided to prove that the demonstrated properties have cases of application.Received: 11 June 2001, Revised: 18 February 2003, JEL Classification Numbers: L1, D43.Grateful thanks are due to Jacques-François Thisse, Jean-Jaskold Gabszewicz, an anonymous referee and especially to Jean-Marc Bonnisseau and Xavier Wauthy for very helpful suggestions and discussions. The revision took place partly when the author was visiting CERMSEM, Université de Paris-I, Paris then CORE, Louvain-La-Neuve, Belgium. Hospitality of both institutions is also acknowledged. |
