"A critical review of the main methods to treat undesirable outputs in DEA," MPRA Paper

The  treatment  of  undesirable  outputs  in  Data  Envelopment  Analysis  (DEA)  has  received great research attention recently. As such and as are presented in this work, there are four possible options to deal with those: first ignoring them from the production function; second treating them as regular inputs; third treating them as normal outputs and fourth performing necessary transformations to take them into account. Also new model propositions for their treatment are  being presented.