Non symmetrical Effect of Large Industrial Segment's Number on Iran's Gini Coefficient

The main reason of this study is investigation in effect of the number of large industrial segments on Gini coefficient from 1974 to 2012. To this end, linear and nonlinear models are estimated. The results show that nonlinear model has more explanatory power than linear model. We defined three threshold include up, middle and down threshold, with regard to acceptance of nonlinear model. The results also show that variation in the number of industrial segment of last period has the most effect on current Gini coefficient in low threshold and is reduced with moving toward up threshold. The results also show that variation in the number of industrial segment of last period has the most effect on current Gini coefficient in low threshold and is reduced with moving toward up threshold.