Determination of optimal economic uncertainty index for Iranian economy

In the present study, the optimal economic uncertainty index for the Iranian economy during the period 1990: 1 to 2017: 4 has been determined. In this regard, contemporaneous economic; uncertainty function, which includes variables of output growth gap, inflation gap, exchange rate growth gap and monetary base, is specified along with other structural equations of Iranian economy and its parameters are determined by Symbiotic Organism Search (SOS) optimization algorithm so that minimize the loss function of central bank of Iran. The coefficients obtained for the variables of output growth, inflation, exchange rate and monetary base are 0.22, 1.03, 2.27, and 0.99, respectively, indicating that the two variables of exchange rate and inflation are more important in creating Economic uncertainty. The index is stationary and also indicates a high level of uncertainty in the two seventies and nineties compared to the eighties. The index shows that in only seven sections, the index of uncertainty is approximately zero, all of which are in the eighties, and in other periods the index is positive or negative.;