The Government Size and Trade Openness in Iran: Evidence from Smooth Transition Regression (STR) Model

Considering the importance of the relationship between government size and trade openness, this study has examined the nonlinearity effect of trade openness on the government size in Iran during the period 1991-2011. The results show that trade openness has an asymmetric effect on the government size in the form of a two regime model.Also, in the first regime (when trading volume is less than 39/53% of GDP), trade openness, consistent with the Efficiency Hypothesis, has negative effect on the government size. Whereas in the second regime (when trading volume is more than 39/53of GDP), trade openness, consistent with the Compensation Hypothesis, has positive effect on the government size. Finally, the results show that the size of government increases by increasing the share of government revenues and investment in GDP.