A methodological proposal to determine the optimal levels of inter-municipal cooperation in the organization of solid waste management systems.

The paper proposes a procedure based on data envelopment analysis (DEA) in order to identify the optimal dimension for inter-municipal cooperation in waste management. Given: (a) a set of decision making units (DMUs) and a production process that virtually transforms municipal expenditure in different amounts of sorted and unsorted waste, (b) a set of exogenous variables conditioning the operational environment of the DMUs and (c) a variable used for measuring the dimension of inter-municipal cooperation, the procedure realizes an iterative correction of input values and efficiency scores to purge, first, the effects of the exogenous variables, and then those of the dimensional variable. In this way, an indicator of the impact of the dimensional variable on the efficiency is obtained for each of the observed DMUs.