فصلنامه اقتصاد مقداری
سال سیزدهم شماره 4 (پیاپی 51، زمستان 1395)

Sector of countries economy related to shadow economy. Production in sector of the shadow economy associated with evading rules such as environmental laws. On this basis¡ activity of most economic units in the shadow economy have the negative externalities. In Program of the sustainable development¡ has been considered environmental quality. The growth of shadow economy is one of the factors that destroys environmental quality which depends to various factors such as corruption. In this paper¡ has been studied the relationship among corruption¡ shadow economy and environmental pollution using linear structural relationship pattern for OPEC like Iran countries over (2000-2012). The results from estimated models show that i) there is a positive relationship between corruption and the shadow economy; so that increasing corruption by one unite lead to rise the shadow economy by 73/0¡ ii) increasing illegal activities in sector of the shadow economy have the significant and positive effect on the environmental pollution indexes; so that¡ with growth of the shadow economy by one unite¡ are affected environmental pollution indexes include carbon dioxide emissions¡ consumption of fossil fuels and forest area by (0.91)¡ (0.47) and (-0.53)¡ respectively.

Corruption is a worldwide problem that hardly one can overstate about its negative consequences. Two kinds of corruption can be considered¡ one is proposing bribe to bend the rules (bureaucratic corruption) and the other is to lobby with the government (political corruption) to set favorable new rules. Through analyzing the two types of corruption in 57 countries¡ the results show that political and bureaucratic corruptions are complement. However¡ this complementary relation is not symmetric; bureaucratic corruptions has a greater effect. It was shown that economic development reduces the bureaucratic corruptions and substitutes it by political corruption. Among governance and political factors¡ efficiency of judiciary system brings bureaucratic corruptions down and other variables like difficulty of access to government¡ uncertainty of regulation and the proportion of health expenditure in public budget as indicators of government behavior in policy making have negative effects on political corruption. One prominent contribution of this paper is its focus on social factors like bribery disapproval and culture of collusion. The results point to the great role of social factors such that a 10 percent increase in bribe disapproval decreases the corruption score by 20 (it could¡ for example¡ improve Iran’s position by 75 in Corruption Perception Index ranking). The effect of business cooperation is also significant. A five percent increase in membership of business cooperation leads to one percent higher influence on government.

In this research¡ with the help of multisector DSGE model¡ the effect of oil windfall revenues on Iran᾽s economy under one of the money policy scenarios will be analyzed. Our definition of money policy scenarios consist of full absorption of oil income in reserves and fiscal policy (full spending of oil income) in relation to tradeable and nontradeable commodities. Aim the appropriate transmission channel of the oil income shock for the structure of Iran᾽s economy has been founded. Comparing the real data moments with the simulated amounts shows the relative success of the presented model for simulating Irans economy during the period between 1978 to 2013. Moreover¡ the results show a temporary increase in demand and also increase in the value of real exchange rate.

The aim of this study is to identify and ranking the factors predicting stock price bubble in the Tehran Stock Exchange. For this purpose¡ at first through skewness¡ Kurtosis and runs tests on price of 158 stock symbol bubble status during the period from 1389 to 1392 were identified. According to research literature¡ affecting factor including information transparency¡ leverage¡ liquidity¡ ratio of book value to market value¡ p/e¡ liquidity¡ institutional ownership and firm size were used. Then¡ using logistic regression effect of this variable on price bubble was confirmed. Results show that the increase in transparency variables¡ B/M¡ liquidity¡ institutional ownership and firm size reduces the probability of forming bubble in share prices. After training artificial neural network¡ using the sample data the network were optimized by out of the sample data. Finally¡ using sensitivity analysis through neural network¡ these variables based on the ability to predict the share price bubble were ranked.

Given the importance of the money market in Iran, this study tries to examine effective factors on net interest margin with an emphasis on market structure and credit risk. Research methodology is based on econometric panel data from 13 commercial banks in the years of 2006-2013. The findings emerged from data analysis show that the average of net interest margin is 4.1 percent at commercial banks. Also market concentration index confirms competitive structure at money market. Credit risk calculations also show that 1.15 percent of bank facilities and receivables has become to past due receivables, Deferred and doubtful. In accordance with the results of the data analysis, the findings of estimation model also confirms the existence of imperfect competition in the money market. Other finding indicates a positive influence of credit risk and administrative costs on net interest margin. However, the bank facilities do not have a significant effect on net interest margin. Because of the large size of government and consequently the dependence of monetary policy to fiscal policy, bank facilities are binding directly or indirectly.

This article examines the robust determinants of public sector (government) size in the Organization of the Islamic Conference (OIC) member countries (includeing Iran) during the years of 1996-2013, under uncertainty of model. For this purpose, is used of the 24 variables that effect on the government size according to theoretical and empirical studies in three categories: economic, political and social variables. Bayesian Model Averaging approach (BMA) is used, due to convenience feature to consider the uncertainty assumption of model. With estimation of 100000 regressions and Bayesian averaging of coefficients, robust determinants of government size are specified. According to the results, population and dependency ratio variables, respectively, with positive and negative symptoms have a certain effect on public sector size. The impact of land area and economic globalization variables on public sector size with a positive sign is relatively important. Coefficients and significant of dummy variables used in the model also shows that countries with a federal structure and countries with presidential systems, have a smaller public sector size and oil-exporting countries, have larger public sector size than the other countries studied.

The effect of tax on economic activities is an important issue in public finance. The fact that the existing system may decrease the investment motivation and consequently decrease the future life style is a great crisis. In addition to, the effects of tax system on capital formation, it can affect financial development and economic growth. In this paper, by simultaneous equations system in GMM method, the impact of capital gain tax on the capital formation , financial development and economic growth in Iran will be studied in the period of 1970-2014. The results indicate that the capital gain tax growth rate, with three lags, increases the physical capital formation growth rate. Also, capital gain tax growth rate, with three lags, decreases the financial development growth rate and increases the economic growth rate. Also, the value of J statistic and value of chi-square statistic indicate that all the entered tool variables in simultaneous equation system are valid and all the patterns are estimated correctly.