The Effect of Internal and External Capital Stock on Value Added in Iran's Medium and Large Industriesand External Capital Stock on Value Added in Iran's Medium and Large Industries

In this study, the effect of internal and external capital stock on value added of Iranian medium and large industries is investigated over the period of 1994-2007. For this purpose, a Cobb-Douglas model is used in which production is a function of labor, internal capital stock, external capital stock, human capital and internal R&D. We estimate this model for 22 industrial groups by applying panel data approach. The results indicate that internal capital stock, external capital stock, human capital and internal R&D have a significant positive effect on value added of Iranian medium and large industries. Also results indicate that as expected labor has positive effect on value added of investigated industries, but is not statistically significant.