Evaluating TFP Changes in Underconstraction Trade By Using Combined Approach of PCA(Case Study: Sub-Sector Road Transportation)

Typically, Two Parametric and Nonparametric methods are used for calculating Total Factor Productivity (TFP). One the famous nonparametric method is Tornqvist index. In this method, which is based on linear programming especially Data Envelopment Analysis, TFP of one DMU is evaluated during a specific period using some inputs and outputs. In this paper, TFP in road transportation sub sector is evaluated by using Tornqvist index. However, one of the assumptions of this method is that three multiplied by total sum of inputs and outputs should not exceed the number of DMUs. The results show that average technical and technological efficiency and TFP growth are equal to 0. 94, 0. 988, and 0. 932 during period 1377 to 1387, respectively. Also, TFP growth in this sub sector in all considered periods except two periods is negative.