Using a nonparametric technique to measure the cost efficiency of postal delivery branches

A multiple-input and multiple-output model for measuring the cost efficiency of postal delivery branches is proposed. We analyze the complete postal network of the Serbian post delivery offices, which includes 1,194 post office branches. To compare the branches that operate under the same or similar conditions, the branches are grouped into 18 clusters by implementing the appropriate clustering algorithm. This enables a three-level analysis: branches–clusters–network. The cost efficiency of the branches is measured using data envelopment analysis. The efficiency of a particular cluster is calculated as an average cost efficiency score of the branches that belong to this cluster, and finally, the efficiency of the postal delivery network is assessed. The distribution of cost efficiency scores per clusters takes values from 15 to 92 %. At the level of the total network, the cost efficiency is 40 %, which indicates that there are possibilities for improvement. To obtain more specific guidelines, that is, the decomposition of cost efficiency into pure technical efficiency, the scale efficiency and allocative efficiency were assessed for each cluster and for the total delivery network. This research is beneficial to policy makers defining the scope of universal service obligation and to company managers who want to optimize the postal network. For example, the results of this study indicate that, at a minimum, 794 delivery branches could improve their efficiency by resource reallocation.