Reference
Catherine Cazals (TSE and IDEI), Paul Dudley (Royail Mail Group), Jean-Pierre Florens (TSE and IDEI), and Michael Jones (Royal Mail Group), “The Effect of Unobserved Heterogeneity in Stochastic Frontier Estimation: Comparison of Cross Section and Panel with Simulated Data for the Postal Sector”, Sixth Conference on "Regulation, Competition and Universal Service in the Postal Sector", Toulouse, France, March 25–26, 2010.