‎Maximum likelihood estimation of multivariate distributions needs solving a optimization problem with large dimentions (to the number of unknown parameters) but two‎- ‎stage estimation divides this problem to several simple optimizations‎. ‎It saves significant amount of computational time‎. ‎Two methods are investigated for estimation consistency check‎. ‎We revisit Sankaran and Nair's bivari...

Traditional DEA models ignore the internal process of production systems and are not able to identify the cause of deficiency in efficiencies measuring. At this research, traditional DEA model and two-stage DEA model were used to measure the efficiency of Iranian private insurance companies during 2007-2009. The results indicated that the traditional DEA model is not suitable for such kind o...

data envelopment analysis (dea) is a powerful tool for measuring relative efficiency of organizational units referred to as decision making units (dmus). in most cases dmus have network structures with internal linking activities. traditional dea models, however, consider dmus as black boxes with no regard to their linking activities and therefore do not provide decision makers with the reasons...