“…More specifically, in productivity analysis, most papers adopt the Malmquist index (Murillo-Melchor, 1999;Gillen and Lall, 2001), which is based either upon Shephardian input-or output-distance function, compatible with the objectives of cost minimisation, or on revenue maximisation (Färe and Primont, 1995). However, in some cases, it might be preferable to assume profit maximisation, which is the traditional assumption in economic theory (Färe et al, 1994;Chambers, 1996;Chambers and Pope, 1996;Balk, 1998;Briec and Kerstens, 2004).…”