فصلنامه مدلسازی اقتصادی
سال پنجم شماره 4 (پیاپی 16، زمستان 1390)

This paper examines the dynamic relationship of stock markets, stability, predictability, volatility, and persistence of shocks volatility of stock markets in Iran, Saudi Arabia, United Arabic Emirates, Qatar, Bahrain and Oman. In this paper, Generalized Autoregressive Conditional Heteroskedasticity model (GARCH) and Autoregressive Moving Average model (ARMA) are implemented by using monthly data during 1990-2010. The results indicate that stock market doesn’t have notable predictability in Iran and there is Cluster volatility for return of stock in most markets and almost, in none of these markets except Oman, explosive volatilities are observed. It is also indicated that the return for markets of Bahrain and Oman doesn’t have stability in significant level of 5 percent and for Iran it doesn’t have stability and durability in significant level of 1 percent. In addition, although the markets of these countries have high capacities for return of investment, but, in particular, the findings show a low correlation between these markets. Also, the results for the period in question explain that none of these markets has the ability of leadership among others.

The purpose of financial markets liberalization followed by most developing countries in recent decades is to improve the efficiency of financial markets and financial resources. This paper examines the relationship between share prices index and financial liberalization index in Iran during 1373-1387 using quarterly time series data. It uses more comprehensive and recent technique, Vector Autoregressive and Co-integration approach to determine the short run and long run linkages between share prices Index and financial liberalization. The findings indicate that financial liberalization index has a positive impact on share prices Index in long run, but no impact in short run. Financial liberalization and reforms started in early 1990s, as part of economic reforms, has a very strong direct effect on the stock market. It means that stock market is too much sensitive and volatile to financial liberalization in emerging economies.

This study is aimed to analyze the effect of uncertainty in the current and constructional Governments Expenses on the investment of private sector in Iran during 1959-2006. Other descriptive variables such as Gross National Product (GNP) and inflation rate are considered. For calculating the uncertainty, an Exponential Generalized Auto Regressive Conditional Heteroscedaticity Model is used (EGARCH (0, 1)). Finally, by the determination of optimal lag and long-term relation, error correction model of VEC was estimated.The results explain that uncertainty of the current and constructional expenses of the government has negative effect on the investment of the private sector in long term. According to this, in short term, uncertainty of the current governmental expenses is not statistically significant on the investment of the private sector, but uncertainty of the governmental constructional expenses has a positive effect on it. The effect of Inflation rate and GNP variables, in short and long term, is negative and positive on the investment of the private sector.

This article investigates the pattern of trade specialization and productivity of exports on economic growth in MENA countries during 2009-2001 using generalized method of moments discussed. The results showed that there is a positive effect on exports and productivity indicators and the negative effect of exports on economic growth indicators heterogeneity between industrial, commercial and trade on economic growth. Among the indicators, only the effect of concentration of exports on economic growth is consistent with the theory that the cause of its extreme dependence on oil economies is of MENA region.

The impact of tax ratio on the investment, in economic activity such as tourism sector, is important in tourism literature. So, the main objective of this study is to investigate the impact of tax ratio on the tourism receipts in MENA countries during 1995-2009.The model of study has been estimated by applying dynamic panel data approach and GMM estimator. The empirical results of study reveal that tax ratio has negative effect on the tourism receipts and GDP per capita and its growth have positive and significant effect on the tourism receipts in such countries. Hence, the main policy implication of this study is that the policy makers, in these countries, should adopt these policies to improve the tax revenue. Because, any increase of tax revenues can decrease the dependency to the tourism receipts. Moreover, the increase of GDP and GDP per capita can improve the tourism receipts in MENA countries.

The investigation of consumer behavior in rural and urban areas of west Azerbaijan province and comparing it to the whole countries the main purpose of this paper by using systematic demand of minimum cost of living. The results of this study show that the most marginal propensity in urban and rural area of west Azerbaijan province and rural of Iran is devoted to "Foods, Beverages and Tobacco groups", but in urban area of Iran it is devoted to "Other groups". The summation of minimum cost of living in urban and rural areas of west Azerbaijan province was more than urban and rural areas of the whole country respectively.

This paper investigates the economies of scale of higher education in Islamic Azad University. We use the long-run Translog multi product cost function and estimate, respected to the homogeneity and symmetry restrictions, to use Systematic Iterative Seemingly Unrelated Regression (ISUR). The data will be collected from 29 selected branches of Islamic Azad University during 2000-2005.Results indicate diseconomies of scale in level of undergraduate education and economies of scale in level of postgraduate education and an optimal number of students for undergraduate education is 7000 to 9000 and for postgraduate education is 800 to 1000.