Examining the Threshold Effects of Export Complexity on the Equal Distribution of Income in Iran

In this research, the threshold effects of export complexity on the equal distribution of income in the country have been investigated using non-linear STAR P-models based on Zhou et al.'s method from 1371 to 1402. The research results show that the export complexity variable has a U-shaped relationship with the equal distribution of income. The export penetration index variable has two threshold values. In the first regime, when the variable of export penetration (Kd) is => 35.14658, the influence of export complexity on the equal distribution of income is negative and equal to 0.20 percent. While in the second regime, when the export coverage variable is Kd > 35.14658, the impact of export complexity on income distribution is positive and equal to 0.99%. Also, the export destination diversity variable has two threshold values. In the first regime, when the export destination diversity variable (Kr) is <= 17.98, the influence of export destination diversity is negative and equal to 0.08 percent. While in the second regime, when the export destination diversity variable is Kr>17.98, the impact of the export destination diversity on the equal distribution of income is positive and equal to 0.62 percent, and as a result, the equal distribution of income will improve by the same amount.