Efficiency and productivity of Norwegian tax offices

The performance of local tax offices of Norway is studied over a three year period applying Data Envelopment Efficiency analysis and a Malmquist productivity index. The estimates are biascorrected using a bootstrap approach recently developed for DEA models. The results show that bias correction and the construction of confidence intervals give a quite different picture than without bootstrapping. A set of best practice offices is identified for future work on finding explanations for good performance. The productivity development of individual offices is classified into the four categories efficient cost increase, efficient cost savings, inefficient cost savings and inefficient cost increase.