فصلنامه پژوهش ها و سیاست های اقتصادی
پیاپی 60 (زمستان 1390)

The impact of devaluation of currency on trade balance can be studied in short and long run, which refers to J-curve effect and Marshall-Lerner Condition respectively. The purpose of this paper is to empirically study the effects of depreciation of I.R.Rial on the Iranian external trade balance, particularly, with the eleven world countries which constitute the over 65 percent of Iran’s foreign trade partrers, in two cases of short and long runs and for the years 1979-2006. This countries consist of: UAE, Germany, China, Italy, Switzerland, India, France, South Korea, Japan and UK and Turkey. In our study, we have used Eviews6 and to run VAR and IRF to estimate the envisage model. The empirical results suggest the existence of Marshal – Lerner condition for trade balance with the world as well as with UAE, Switzerland, India France, South Korea, Japan and UK. also the J- curve effect, at aggregate level and disaggregate levels, except in the case of Turkey, does exist.

The main purpose of this study is to investigate the relationship between financial development and economic growth, by using new variables such as domestic credit provided by banking sector, domestic credit to the private sector, broadest definition of money, gross domestic saving and also government expenditure and trade. The 2 latest variables represent real sector of economy, and inflation, during1967-2007. The estimate of long run relationships between variables shows negative relationship between growth and financial development. However, short run relationship between growth and financial development have been done by Granger causality block erogeneity test that findings show domestic credit provided by banking sector doesn’t entails causality Granger of growth. Finally, the relationship between growth and domestic credit to the private sector is the two way causality.

Elderly population which has tripled in the past four decades requires more attention to pension plans and social security programs. This study explains the factors that affect the formation and development of social security programs in different countries in the framework of political and, economic - population theories. Based on these theories, the paper also analyzes the relationship between the political structure and social security plans. To this end, Dixon index is used as an indicator for determining social security efficiency in a regression model to analyze the political and economic factors effecting the efficiency of social security programs. The results show that in countries that enjoy greater degree of political freedom, the social security systems have higher efficiency. While for the rich and poor countries who suffer from the lower degree of political freedom, political factors have little role. In this content, economic factors including the share of aged population (65 years old and more) and also unfair income distribution have more effect on the efficiency of social security system in these countries.

Electricity industry in Iran has passed four evolutionary stages: regulation, deregulation, restructuring and privatization. Regulation increased the directorial and proprietorship role of the government. Deregulation changed the laws which had helped the continuity of the government role in electricity industry and therefore provided a legal framework for the private sector to contribute to power industry. Restructuring, disintegrated the vertical monopoly into production, transmission and distribution sectors. Privatization resulted in transferring the ownership of electricity units to non-governmental sectors. This paper tries to explain the effects of the Iranian electricity structural reform on the productivity of electricity industry by using DEA and Malmquist Index approaches. Results confirm that productivity has been improved, and show that the change in technical efficiency has contributed more than technological development to this process.

Using tests of Panel Unit Root, Panel Co integration, and Dynamic Ordinary Least Square (DOLS), this study tests, analyzes, and explains the impact of economic growth on renewable energy consumption in two groups of selected OECD and non-OECD countries for the period 1980-2008. Results indicate that there is a long-run co-integrated relationship between economic growth and per - capita renewable energy consumption in both groups; coefficients of variables are statistically significant and positive. Moreover, the long-run impact of economic growth on per - capita renewable energy consumption in OECD countries is greater than that of non-OECD countries.

Higher competitiveness of knowledge – based industries is critical to national economy of developing countries, became it plays a direct role in creating value – added and bringing in foreign exchange. Their positive achievements spill over on the other sectors which in turn lead to higher productivity and bigger businesses. One of the main objectives of this study is to assess Iran’s competitiveness in knowledge – based products’ trade with Southwest Asian countries. The method used is based on variations in weighted markets, resulted from constant market share (CMS) model, relied upon both sides’ realized or Ex-Post export – import values during 2000-2008, as well as Harmonized Commodity Description and Coding System. The results show that Iran’s share and position are neither desirable nor encouraging, though such exports have increased. If this situation persists, achieving the goals of Iran's Economic Prospect Plan will became difficult. Dynamic constructive interaction with industrial countries, providing the grounds for absorbing foreign investment, and outward – looking trade policies could enhance Iran’s competitiveness in this field.

The main goal of this paper is to study and compare the predicting power of Hedonic pricing model and Artificial Neural Network (ANN) model and determining the optimum model for forecasting the housing prices for the city of Tabriz. The results of the estimation of the price function show that most of the variables in the Hedonic pricing model are significant with the expected signs, according to the theory. Physical factors have more important effect than locational factors (environmental and accessibility) on the housing prices. Among the structural characteristics, having lobby, swimming pool, number of bedrooms, and the frontage of the building are the most important factors affecting the prices. The most important locational characteristic on the housing price is the distance to educational centers. For our comparison, we have utilized MSE, RMSE, MAE and R2 criteria. According to all criteria, ANN model had less error in prediction of the housing Hedonic prices for the city of Tabriz. In order to test the hypothesis of equal predicting power of the two models, we have used MGN test. The result of this test indicates that the ANN approach is statistically superior to hedonic model.

In this paper, we have studied the effects of financial shocks arising from increased government subsidies on real consumption of private sector in Iran, by using Auto - Regressive Distributed Lag (ARDL). Results of the estimated models show that long-term and short-term relationships can be seen between real consumption of private sector and subsidy shocks. According to the research results, under the stag- flation situation which is currently prevailed in Iran’s economy, creating a negative subsidy shock certainly reduces real private sector consumption in the short run. But, given the relatively high adjustment speed obtained from the model, there is a hope that the situation gets resolved in the medium term. Also the effects of these shocks on real private consumption will come close to the status of balance in the long-term.

Expansion of telecommunication networks and its impact on various aspects of human life, including economic one has increasingly drawn the attentions to the mobile system of communication. Therefore, in this paper the demand for mobile phones (MCI) and the impact of several variables such as the numbers of immobile phones, BTS antenna, operator SIM card price index, GDP per capita, are investigated. The data measured annually, are collected from 28 provinces for the period of 2000-2008. New operator variable was entered into the model as a dummy variable. Data were gathered from Iran Communication Co. and Iran Statistics Center. At first, the model was estimated for 2000-2005 period. (Irancell entered to the market in 2006). Then estimation was done for 2006-2008 with no second operator. Finally, estimation was conducted for 2000-2008, with inclusion of the second operator. In continuation, a suitable pattern was selected for estimation, using Limer and Hausman tests. The model was estimated by fixed effects method for 2000-2005 and by random effects method for 2000-2008. The results showed that there is a positive and significant relationship between entering the new operator and the demand for the services of Hamrah-e Aval Co. (MCI), and this demand was increased by entering the new operator. Also, price elasticity of demand for MCI is low and therefore it's services are considered as essential goods.