  This paper proposes a novel slacks-based interval DEA approach that computes
interval targets, slacks, and crisp inefficiency scores. It uses interval
arithmetic and requires solving a mixed-integer linear program. The
corresponding super-efficiency formulation to discriminate among the efficient
units is also presented. We also provide a case study of its application to
sustainable tourism in the Mediterranean region, assessing the sustainable
tourism efficiency of twelve Mediterranean regions to validate the proposed
approach. The inputs and outputs cover the three sustainability dimensions and
include GHG emissions as an undesirable output. Three regions were found
inefficient, and the corresponding inputs and output improvements were
computed. A total rank of the regions was also obtained using the
super-efficiency model.
