Slacks-based measure of efficiency of airports with airplanes delays as undesirable outputs

This paper reports the slacks-based measure (SBM) of efficiency of 39 Spanish airports for years 2006 and 2007. In addition to the conventional outputs (namely aircraft traffic movements, passenger movements and cargo handled), two undesirable outputs have been considered: percentage of delayed flights and average conditional delay of delayed flights. The inputs considered quantify the physical infrastructure of the airports and are considered non-discretionary. The proposed Data Envelopment Analysis (DEA) approach assumes variable returns to scale and joint weak disposability of the desirable and undesirable outputs. The SBM model used has been found to have more discriminatory power than the common directional distance function approach. Also, the inclusion in the analysis of the undesirable effects of airport operations leads to more valid results. The results show that in both years more than half of the airports are technical efficient with the rest showing in general large inefficiencies due to slacks in the different outputs, slacks that the proposed SBM approach is able to identify and quantify. Overall, the system has significant improvement potential in cargo and to a less extent in passengers and percentage of delayed flights.