Considering spatial effects in the evaluation of joint environmental and cost performance of municipal waste management systems

In an article recently published in this journal, Sarra et al. (2017) presented an approach to measure the efficiency of municipal waste management systems (MWMSs) that allows a joint consideration of their performance in both environmental and economic terms. Such an approach does not consider the existence of the effects of spatial proximity among municipalities. This could result in biased efficiency scores that may lead to inappropriate policy decisions. To overcome this weakness and to provide policy makers with a more reliable tool for the joint evaluation of the environmental and cost performance of MWMSs, this paper proposes to integrate a multistep procedure that would control for spatial effects with the approach of Sarra et al. (2017). This paper also presents an application of the proposed approach to the same data used by Sarra et al. (2017) to allow a comparison between the results obtained. The findings of this study suggest that jointly assessing the environmental and economic efficiency of MWMSs through data envelopment analysis-based methods can lead to distorted judgments if spatial effects are not properly taken into consideration.