The Effect of Exchange Rate Uncertainty on Agricultural Trade Balance (An Application of GARCH, EGARCH and TGARCH Model)

Exchange rate Fluctuations and consequently relative price fluctuations, through making economic conditions unstable and increasing inflation, increase uncertainty in the field of foreign trade that it causes such consequences as reducing volume of trade, foreign direct investment and economic growth. In this study to investigate the effect of exchange rate uncertainty on Iran's agricultural trade balance, first through ARMA model, Behavioral equation of exchange rate was explained and then by doing test and making sure of asymmetric shock effect, the index of exchange rates Uncertainty was obtained through TGARCH pattern. Then long run equilibrium relationship was estimated through Johansen-Juselius and for the period of 1983-2011. The results show the index of Exchange Rate Uncertainty, according to TGARCH Model, is significantly negative in long run so higher the exchange rate uncertainty, worse the agricultural trade balances. In addition an increase in the GDP of business partners and real exchange rate improves the trade balance, while an increase in Iran GDP worsens it in the long run. Also the results of Error Correction Model show that the fluctuations of the exchange rate in the short run have a significant negative effect on the agricultural trade balance while the effect of the other variables is the same with long run. Furthermore the coefficient of ECM is -0.39, so in each period 39 percent of the shocks in the short run are adjusted to long run.