Long-Run Growth of IRAN's Economy from the Lens of Export-Led Growth Model (Application of the Time-Varing Approach)

In 1979, Tirlwall introduced a model called the Balance of Payments Equilibrium (BOPE) model, stating that demand growth could be curbed by the balance of payments deficit, thus limiting further economic growth. The important point in examining the Tirlwall law is the important role of oil exports in providing foreign exchange resources and the important role of these resources in the balance of payments in oil-rich countries such as Iran. The aim of the present study, in the first step, is to validate the Tirlwall model by estimating the balance of payments equilibrium growth in the Iranian economy during the period (1982-2018) by using the Kalman Filter approach in the form of a Time-Varying Process (TVP). This method is able to consider the structural changes of the economy that affect trade elasticities and include them in the model. Then, the factors affecting the growth rate of BOPE in the Iranian economy have been studied by examining 10 related explanatory variables. For this purpose, Bayesian Model Averaging (BMA) technique has been used. The advantage of this method is in increasing the quality of average estimation and solving the problem of uncertainty due to model specification and instability of coefficients. The results of the study show that in general in the Iranian economy, the Tirlwall law is not valid and therefore the balance of payments does not limit effect on economic growth in Iran. Also, in examining the factors affecting the growth rate of BOPE, this study emphasizes the importance of the direct and indirect effect of aggregate demand on the income elasticity of imports and export growth through capital accumulation (especially fixed asset investment).