Estimating the Direct, Indirect and Total Effect of Defense Expenditures on Iran's Economic Growth: A Simultaneous Equation System Approach

The defense sector in any country is one of the strategic sectors of that country that plays an important role in creating internal and external security and directly and indirectly affects economic growth through various channels. Iran's position in the sensitive and strategic position of the Middle East and facing the security threats of foreign countries, has led to a significant share of public sector spending to the defense sector. In this regard, the main purpose of this study is to estimate the direct, indirect and total effect of defense expenditures on Iran's economic growth during the period 1989-2018. For this purpose, a model of simultaneous equation system is used and the three-stage least squares method (3SLS) is selected as the appropriate method for estimating it. The results of model estimation show that the direct effect of defense spending on economic growth is positive; In such a way that with a one percent increase in the country's defense burden, economic growth will directly increase by about 0.17 percent. In contrast, the indirect effect of defense spending on savings and trade balance is negative and significant. Estimation the total defense spending effect on economic growth also shows that with a one percent increase in the share of defense spending in GDP, the country's economic growth decreases by about 0.09 percent.