Big and Beautiful? On Non-parametrically Measuring Scale Economies in Non-convex Technologies
Kristof de Witte, Rui Cunha Marques
Journal Of Productivity Analysis, vol. 35, 2011, p. 213-226.

Is Big Better? On Scale and Scope Economies in the Portuguese Water Sector
Rui Cunha Marques, Kristof de Witte
Economic Modelling, vol. 28, 2011, p. 1009-1016.