فصلنامه اقتصاد مقداری
سال چهارم شماره 3 (پیاپی 14، پاییز 1386)

In this paper, we investigate the relationship between trade liberalization and tax revenue of government in Iran, over 1966-2005, using Autoregressive distributed lag method. The results indicate that trade liberalization has substantial negative effect on the tax revenue. For this reason, we suggest that government should increase productivity by implementing policies such as privatization and increasing private sector activity and decreasing protection policies, such as tax exemption.

In this paper we investigated the comparative advantage of rice production and we estimated the trend of its importation to Iran for 2015. We try to underline the production problems and we survey the factors that increase the importation.Using on OLS method to estimate the rice importation for the period of 1990-2005, we found that ratio of importation to domestic production, depends on importation price, domestic price and domestic consumption.Also using time saris and ARIMA model to forecast the rice production and consumption under the present circumstances show that Iran has no comparative advantage in rice production. But the government support causes a positive profit for the producers. Our research found that in the next decade rice production and consumption increases but the its importation increases as well.

Process of decision making needs to be analyzed because the effects of important factors in investing environment must be considered. These factors are macroeconomic factors such as Inflation rate. Investors tend to invest in firms where they are more valuable. One index that is used to calculate the value of firms is Tobin's Q index. Based on this, the main hypothesis of this research expresses that there is a relation between firm's value and the inflation rate. The literature is gathered by library research and for the analysis, the inductive and deductive methods are used to accept or reject the hypothesis, and the relation between Tobin's Q index with inflation rate is assigned by the analysis of the amount of correlation and regression. Statistical population of the research included 285 firms. According to the results of the test, there is no relation between firm's value with inflation rate in 11 years and the coefficient of correlation is meaningless. Also testing the subsidiary hypotheses shows that the effect of inflation rate on the firm's value is not approved.

This study investigates the relationship between public investment in transportation and economic growth in Iran, by using traditional instrumental variables models and new mixed fixed and random coefficient approach in a dynamic panel model framework. Transportation is an infrastructure and has bilateral relationship with economic growth, that's why determining causality between this two variables approximately can be useful to make public investment decisions in this sector. Empirical literatures on the relationship between two variables has reported a mixed picture in different countries. To Explain the causality between public investment in transportation and economic growth in Iran, we find out that economic growth has a positive and significant effect on public investment in transportation proposed by the Investment Acceleration Hypothesis and Wagner's low. Investigating reverse causality expressed that there is a significant heterogeneity across country's provinces and for this reason, public investment in transportation has no significant effect on economic growth.

Mineral materials form the main part of industrial inputs. The existence of plenty mineral materials can provide basis for industrial growth and development. As mines are exhaustible resources, optimum usage of them is very important. On the other hand existence of the plenty of different mineral materials all over the country is one of the advantages of Iran. Sarcheshmeh Copper Complex is the largest and the most important mine in this field in the country. Due to the role and importance of the complex, present study deals with its activities in point of view of the Cost- Benefit Analysis. To achieve this, two criterions of Net Present Value (NPV) and Benefit-Cost Ratio (BCR) are used. The study of these criterions shows that Net Present Value of the complex has been over 56846 billion Rials and Internal Rate of Return has been 31.5 percent, during 1370-84. While its present value of the future activities estimate around 5313 billion Rials. Therefore, its activities have had economically justified. Sensitivity Analysis also is used to determine the affects of uncertainty variables on the results.

This paper investigates the effect of national income, exchange rate and relative import prices on the import demand function and also global income, exchange rate and relative export prices on the export demand function for the period (1959-2006) in the Iranian economy. We employed the autoregressive distributive lag (ARDL) model for the estimation of these functions. The empirical results from both ARDL and error-correction models show that national income has had a significant and positive effect, while relative import prices and the exchange rate have had a negative effect on the Iranian import demand function. Through the estimation of the export demand function we found that global income variables and exchange rates have a significant and positive effect and relative export prices have a negative effect on the export demand function in the Iranian economy. Empirical results also show that the speed of adjustment in the Iranian export and import demand functions is relatively high. Finally our empirical findings suggest that the Iranian trade balance improves as the exchange rate, relative import prices and global income increases and as relative export prices decrease.

The main goal of this paper is to investigate the causality between money and inflation in the Iranian economy. In doing so, we have first reviewed theoretical and empirical literature of causality throughout the world and then we used Granger''s method for detecting causality between money and inflation in the Iranian economy. We then used Johansen procedure in order to test weak exogeneity for taking result that weather money affect inflation or vice versa. The results show that in the short run, money causes inflation but in the long run money cannot affect the inflation. Moreover in the short run monetary policy is effective, whereas in the long run money stock is only passive.