---

The traditional theories of international economics emphasize on national currency devaluation as an efficient policy to enhance export, reduce import and consequently reduce current account deficit. The latest literature considers asymmetric response of trade variables to exchange rate changes and pays attention to ambiguous effect of reducing exchange rate on trade balance. This is an important finding since the success of trade policy depends on the understanding of the nature of trade balance behavior. The present paper examines Iran’s trade balance behavior in relation to exchange rate using logistic smooth transition regression (LSTR) during 1973-2009. The results of this research show that real exchange rate effects on Iran’s trade balance are asymmetrical and nonlinear. Furthermore, overvaluation of domestic currency effects negatively on the trade balance.

---

With a view to efforts of some countries for the devaluation of the national currency, one of the most important questions in the field of International economics is "whether this devaluation, leads to current account improvement or not? In order to study this important question, this paper is aimed to study the short-run and long-run Effects of the Exchange rate on the trade balance between Iran and selected set trade partner countries in Europe, Asian and the rest of the world. The results of applying Error correction of the Panel data method via FMOLS Estimators demonstrate that real exchange rate variable is negative and insignificant in long-run for the European partners. But this is positive and significant for Asian and whole the world's partners. These results show that while the real exchange rate coefficient in short-run is significant and positive for European, Asian and the world's economic partners, the exchange rate in long-run is ineffective on Iran's balance trade. So these results show that exchange rate enhancement (devaluation) causes an Improvement in the trade balance in the short run. However, these effects disappear in the long run. So the findings show the disapproval of J-Curve for all the partners. Moreover, change in GDP of partners and Iran have significant effects, and their estimated signs are positive and negative respectively.
 

---

The main aim of this study is to investigate the effect of exchange rate uncertainty on trade balance between Iran and countries which are major  trading partner of Iran, using the EGARCH method and the ARDL model (to examine the coherency and short- and long-term dynamics of the model). The data used in this paper includes quarterly data in the period of 1995 to 2017 for the real effective exchange rate, imports and exports of Iran (trade balance is between Iran and the main countries that are considered as trading partners of Iran, including China, Emirate, Germany, South Korea, and Turkey), real GDP of Iran, and real GDP of the main trading sides of Iran. The results demonstrate that, according to the model variables in the short and long term, in the case of changing in exchange rate, the trade balance of Iran versus other trading countries experience different variation, depending on the amount, volume and type of goods that are in business.