Given the characteristics of the data and our objectives, Data Envelopment Analysis (DEA) and Stochastic Frontier Analysis (SFA) are two appropriate methods for testing our hypotheses. Both techniques allow for the derivation of relative efficiency ratios within a group of analyzed units, therefore the efficiency of the units/terminals is compared through an efficient envelopment technique (a comprehensive survey can be found in Lovell 1993; Greene 1993; Hjalmarsson et al. 1996; Aigner et al. 1997; Kunbhakar and Lovell 2000; Coelli et al. 2005). DEA and SFA are well-established methodologies in maritime economics generally and port studies in particular(Notteboom et al. 2000; Cullinane and Song 2003; Barros and Athanassiou 2004;
Tongzon and Heng 2005; Barros 2005; Cullinane et al. 2006; Trujillo and Tovar 2007).