Contribution to a book:

Catherine Cazals, Jean-Pierre Florens, Séverine Rouzaud and Marc de Rycke, "Scale Economies and Natural Monopoly in the Postal Delivery: Comparison between Parametric and Non Parametric Specifications", in Managing Change in the Postal and Delivery Industries, series Topics in Regulatory Economics and Policy, vol. 25, chapter 4, Kluwer, 1997, p. 65-82.

Catherine Cazals, Jean-Pierre Florens, Séverine Rouzaud and Marc de Rycke, "Scale Economies and Natural Monopoly in the Postal Delivery : Comparison between Parametric and Non Parametric Specifications", IDEI Working Paper, n. 58, 1996.