فصلنامه مطالعات اقتصادی کاربردی ایران
پیاپی 21 (بهار 1396)

US auto-making industry began with Ford. This industry was developed better in America than in Europe. Some automobiles entered Iran in the early 1920s. Iran had to withdraw foreign currency and import cars due to inability to manufacture automobiles. Auto-making industry is the center of interest and competition of many countries and international corporations due to its critical role in the lives of people, extraordinary profitability, employment, and extensive turnover. The industry is of great importance due to having a profound link with other economic and industrial sectors and being the world's most advanced technology. Auto-making industry is one of the most important industries to create value-added in the economy of every country. This research aimed to study Iran's auto market power. Various models have been proposed to assess the market power including Perloff and Shen, Twomey and Green, static Bresn and Leo, dynamic Bresn and Leo, Colling and Presston, Panzer and Rosse, Hall, Roeger, Boon, Iwata, Azzam, Appelbaum, and Phophana. In this study, we employed Hall-Roeger Model in order to calculate the Lerner Index and Mark-Up and assess the market power of Iranian passenger cars.
A look at Iran Khodro Co. showed that it manufactured 756669 passenger cars in 2011, accounting for 42.57% of market share. The comparison with the manufacture in 2001 revealed that the manufacture of Iran Khodro Co. accounted for almost 61% of market share (225483 passenger cars). In 2011, the exports of Iran Khodro Co. were almost 18% of total Iranian car exports. It was, however, 5% in 2001. SAIPA manufactured almost 656505 passenger cars in 2011, accounting for almost 36.94% of the total production of Iran. However, it manufactured almost 28.21% of total production in 2001. Lerner Index was employed to investigate the profitability of companies. Greater Lerner Index shows higher profitability. The greatest Lerner index belongs to Kish Khodro Co. (0.787) followed by Morattab Khodro (0.771) and Kerman Motor Co. (0.672). SAIPA has the minimum Lerner index (0.219). Companies which assemble the cars have greater Lerner Index and profitability.
In this article, we used the generalized Hall-Roeger approach to calculate the Lerner Index and Mark-Up for 7 Iranian carmakers from 2000 to 2007. The calculations showed that the greatest Lerner Index belonged to Kish Khodro (0.787), Morattab Khodro (0.771), and Kerman Motor (0.672). The lowest Lerner Index belonged to SAIPA (0.219). Mark-Up was as follows: Kish Khodro (4.7), Morattab Khodro (4.37), Kerman Motor (3.05), and SAIPA (1.28). Greater Mark-Up shows greater profitability coefficient of company. It shows that companies involved in assembly of passenger cars had greater profit margin compared to passenger car manufacturers. Since Lerner Index is greater for Kish Khodro, Morattab Khodro, and Kerman Motor, the National Iranian Competition Center is required to consider an appropriate model for pricing and profit margin by analyzing the structure of costs in these firms.

Energy is one of the most important influential factors in every economy. Energy is used as an intermediate input by firms, as a final commodity by households, and transportation costs are heavily dependent on energy. So analyzing the impacts of energy policies on the economy is very important. One of the common energy problems in many developing countries is energy subsidies. According to IEA, energy subsidy is any government action that lowers the cost of energy productions, raises the price received by energy producers or lowers the price paid by energy consumers. The most common reasons for the introduction of energy subsidies are lowering the cost of production, and consumption and alleviating energy poverty. However, despite some limited benefits, energy subsidy can leads to market distortion, substitution of energy with other production factors, increasing of energy consumption, reduction of incentives for energy efficiency, imposing fiscal burden on government budget, reduction of investment on other technologies of energy production, smuggling of fossil fuels, and environmental emissions. Therefore, reform of inefficient subsidies has the potential to provide substantial gain for the economy, and due to this reason, many countries, including Iran, started energy subsidy reform. Energy policy reform in Iran is multistep reform that the first phase of it began in December 2010, and other phases are going to be implement in the coming years.
Energy policy reform might have considerable effect on income distribution. Since income inequality might cause serious social, political and economical problems, the policy makers should consider the inequality effects of this policy reform. In this paper we analyze the effects of reducing energy subsidies on income level and income distribution in Iran. Analyzing the effects of exogenous policies and shocks on income distribution requires a method that incorporates both aggregate impacts on the economy and the heterogeneity of the effects on households. We used a computable general equilibrium model with heterogeneous households for the study of the effects of reducing energy subsidies on income distribution. This method provides a possibility to simulate the macro and intersectoral effects of exogenous policies, and the heterogeneous effects of policies on households as well. In order to incorporating heterogeneity of households into the computable general equilibrium (CGE) model, we disaggregated household sector in social accounting matrix into 100 rural and 100 urban representative households based on expenditure per capita. Then we estimated the parameters of households demand functions using micro database of household survey data, and then we construct and simulate the CGE model.
In terms of macroeconomic results, the simulations show that energy subsidy reform have decreasing and increasing effects, respectively, on GDP and inflation. In terms of distributional results, one of the advantages of the CGE model with disaggregated households by percentile of expenditure per capita is direct calculation of Gini coefficient. If the policy simulation increases Gini coefficient, then the policy can be thought regressive, and if it reduces Gini coefficient, it can be regarded as progressive. The simulation results show that lowering energy subsidies could have decreasing effect on real consumption of urban and rural households for all income quintiles, such that it reduce consumption of urban household more than rural one, and as we go to higher income percentile this decreasing effect increase with decreasing rate.

Volatility in energy prices is important for both producers and traders. High volatility would also lead to increased demand for storage and thus, to an increase in spot prices and convenience yield. Therefore understanding changes in volatility can help explain changes in other economic variables (Pindyck, 2004b). To accurately measure volatility, it is very important to understand the relationship between energy prices and different goods and services prices, their price determinants, and the underlying factors behind their price fluctuations.
Subsidy Reform Plan of energy is one of the most important sections of economic reform plan which led to change in subsidy payment process in Iran. Based on this plan, government transfer payments for energy that was being done to hold down production costs and thus indirectly control the market price are removed and instead, domestic sale prices of gasoline, gas oil, fuel oil, kerosene and LPG and other oil derivatives, considering the quality of carriers and the associated costs (including transportation, distribution, taxes and legal duties) has been determined such that gradually by the end the fifth five-year Economic, Social and Cultural Development of the Islamic Republic of Iran is not Less than 90 percent of the price of delivery on board (FOB) in the Persian Gulf (Feizpour and Sarkar (2015).
In 2010, with the beginning of economic reform plan, energy carriers price rose drastically. Since energy is one of the main inputs of production in manufacturing sector, this sector, like other production sectors, encountered input price rise. There are some energy carriers which are in the basket of household final consumption and reforming their prices directly would change the consumer price index and part of these carriers have been used as intermediate goods for enterprises that reforming their prices effect on producers price index, and finally changes in producers price index could influence on the increase in the prices of the producing goods of enterprises. The main purpose of this study is to simultaneously estimate price volatility in energy carriers price and price index of goods and consumer.
For this purpose the VAR-BEKK GARCH in two variables is used for investigating of dynamic depencencies between variables fluctuations during the period of April 2002 to March 2016. We followed a multi variable GARCH approach to examine the level of interdependence and the dynamics of volatility between enrgy prices and some goods and services prices to identify and measure volatility spillovers among these variables.
This paper used the BEKK model put forward by Engle and Kroner (1995). The BEKK model is suitable to characterize volatility spillovers across markets because it is flexible enough to account for own- and cross-volatility spillovers and persistence between markets (Wu and Li, 2013). To identify more clearly how the energy price and goods and services price volatilities interact, first consider the bivariate BEKK-GARCH model and choose lag length of VAR. The lag length corresponds to the optimal number as determined by the SBIC. Then testing for return spillovers from one market to the other markets is equivalent to testing the significance covariance of GARCH model.
research results show that any modification or adjustment in prices of energy carriers in addition to its direct impact on the general price level from other ways such as price index of “goods”, “transportation”, “communication”, “entertainment and culture” and “housing” lead to fluctuation and change in total index. Also the results of the spread transmission test from chosen groups on energy carriers price index suggest that the price index of the groups of “education”, “food,tobacco,beverage”, “transportation”, “goods”, “health”, “communication”, “services”, and “clothing” have had the highest transfer of fluctuation in energy carriers price index respectively.

Since 2000, the economic and political deals have been dramatically changed due to the arrival of the euro in to the global currency market. Moreover, the euro currency had an influence on contribution of business trade and other currencies. However, it had a great impact on dollar as worldwide important money. At the moment after 15 years of emergence of euro in to the international finance, it seems that there is passing game between dollar and euro. Nowadays, the investigation of relation between international variables is highly taken in to account due to improvement of international relations particularly in field of economy. The success in international market and adoption of appropriate currency and financial strategy heavily depend on recognition of international environment, variables and influential players. In this regard, the importance of currency issues is considerably high. Throughout last decade, it was observed that in addition to US dollar, the euro have had an extensive presence. This issue led to changing currency policy of countries in which to consider euro against dollar in to their currency basket. The selection of importance ratio of these two powerful money in currency basket may be decisive. It seems that the relation between these two money can be defined not only in business deal but also in form of the game theory. This study is allocated to examine the action and reaction of these two currencies in the international environment. To accomplish this goal, the game theory and statistical model leader - satellite were used. Results indicate that the agreement between euro and dollar has been achieved after one decade struggle in prices. Furthermore, it is concluded that with respect to the proportion of these two currencies in international trade, there is Nash equilibrium in their game. Also, it is worth noting to say that after the crisis and the recent recession in Europe, dollar still plays key role and euro is follower. Other foreign currencies could also achieve satisfactory share of the market.

Foreign or external debt is a tool that governments can use to encourage the investments and economic growth through the development of infrastructures. It plays an important role especially in the developing countries, as most of these countries suffer from the investment shortages and also budget deficits. In addition, in these countries, the savings and export revenues are not enough to finance new investments and import expenditures of the country. In recent years, borrowing has become an important economic problem not only for the developing countries but also for the developed countries as well. In many countries, global crisis and expansionary public policies have caused a rapid increase in the external borrowing.
It is widely known that the wise use of the external debts is necessary to enjoy the benefits of these debts. Otherwise, it will increase the burden on the country in the future and will harm the economy, when the time comes to pay the debts back. In other words, it is necessary to take into account the sustainability and also the efficient allocation of these funds. If the funds that have been raised through debt can be channeled to the investments, they will increase the growth rate of the country and also will make the country capable of paying them back in the future. Otherwise, these funds would reduce the economic growth rate, as a large portion of the government revenues will be used to pay back the debts. Several theories are introduced to link the debt to the growth. Debt overhang hypothesis is one of the theories that anticipates a negative relationship between the external debt and the economic growth. According to this hypothesis, when the external debt increases in a country, investors anticipate that the government will raise the tax rates in the future to gather enough funds to pay the debts back. Therefore, they will invest less, which will reduce the growth rate.
Liquidity constraint hypothesis is another theory that predicts a negative link between the debt and growth. According to this hypothesis, the country will need a large amount of credits in the future to pay the debts back and this will reduce the growth. The accumulation of debt is the third theory that states a negative effect of debt on growth. Based on this theory the government's investment on new technologies, human capital, and financial system will decrease over time. At the same time, a higher debt will increase the uncertainty in the economy which will raise the interest rate and will result in a lower investment.
Considering all these issues, this paper examines the impact of external debt on the economic growth in Iran over the period 1980–2013. To that end, the ARDL approach to co-integration is used. This paper differs from the other papers on this issue in two aspects. First, the effect of the external debts on the economic growth is examined taking into account the presence of different macroeconomic policies. Second, the external debt is divided into bilateral and multilateral debts and their effect on the growth is examined separately.
The impact of external debt on growth is analyzed allowing external debt to interact with the macroeconomic policy index. In addition, the ratio of the external debt to the GDP, the ratio of debt service to the export, and the ratio of multilateral external debt to total external debt also included in the model to examine their effect on the economic growth in Iran.
The results show that external debt has a negative impact on growth, but this adverse effect can be reduced or even reversed in the presence of sound macroeconomic policy. Moreover, the bilateral component of the total external debt is the part that retards the economic growth.

One of the important issues that has attracted economists’ attention, is the increase of competitive power of export commodities through the currency undervaluation in order to achieve the optimal economic growth. Given that the exchange rate system in Iran is a managed floating exchange rate regime, and despite the market forces effect in determining the national currency value, it is expected that the monetary authorities intervene in the foreign exchange market to adjust the national currency value.
Exchange rate is one of the most volatile economic variables in Iran in the past two decades. In the recent years, Iran has repeatedly experienced the exchange rates increases. According to the Central Bank of Iran, in the last 25 years, Iran’s economy has experienced two exchange rate shocks; the first one from 1993 to 1999 and the second one from 2010 to 2011. From 2014 to the end of 2016, the growth rate of the dollar has declined compared to beginning of the period. But, in the early months of 2017, the economy has again experienced a rise in the exchange rates growth and the depreciation of national currency.
Some economists believe that the currency undervaluation will increase exports and reduce imports, and consequently will boost the economic growth. But, most experts believe that currency undervaluation damages Iran's economy by increasing foreign exchange revenues and consequently an increase in the size of the government and also by reducing the purchasing power of the people and high inflation level. Indeed, the currency undervaluation, on the one hand, impacts the basket of assets by reducing the purchasing power of money, and on the other hand affects the demand for import and export. Therefore, due to “imported” inflation, the economic growth will be reduced. China and other East Asian countries, such as the South Korea and Japan, experiences indicate an increase in economic growth through the currency undervaluation. Indeed, for a decade, some economists have refreshed the idea that an active exchange rate undervaluation strategy can efficiently stimulate growth. The revival of this idea has since triggered an intense debate opposing advocators of this claim. Therefore, it is possible that the relationship between currency undervaluation and the economic growth is nonlinear. More specifically, we provide answer to the following question: is there any nonlinear relationship between undervaluation of the Rial and the economic growth of Iran?
The main objective of the present study is to investigate the impact of the currency undervaluation on economic growth in Iran using annual data during the period from 1968 to 2014 in a nonlinear model framework. We calculated the Index of currency undervaluation using CPI of Iran and the United States, then we have adjusted the index according to Balasa-Samuelson effect. In order to answer the above mentioned question and to investigate the nonlinear impact of currency undervaluation on economic growth, we used a smooth transition autoregressive model which is estimated via Newton-Raphson algorithm and conditional maximum likelihood function. The results show that there is an asymmetric behavior of economic growth around a threshold level and different levels of currency undervaluation. In the linear regime (low level of undervaluation), a positive relationship exists between physical capital, size of government, human capital variables and economic growth. In the nonlinear regime (high levels of undervaluation) the relation between mentioned variables and growth is negative. All of our results are consistent with the economic theories. According to the results and in order to achieve the desired economic growth and to avoid the negative effects of national currency undervaluation, this study suggests that monetary authorities avoid to lower excessively the Rial value against other currencies.

Discussion related to improving energy efficiency associated with a problem called rebound effects or Backfire effects, these effects occurs when improving energy efficiency increases energy demand (direct and indirect) in different sectors of production and consumption. This effect occurs when improving technology, resulting in increased energy efficiency. This increasing efficiency have a side effect; become cheaper energy services, that is real price of energy services reduced. With suppose the demand curve downward, service demand increases and part of the expected energy for saving, is consumed. Therefore, the predicted energy saving from improving technology, by increasing the demand for energy services somewhat decreased. The potential importance of the rebound effects are derived at macro level, that the effect somewhat reduces benefits of improving efficiency and perhaps affect effectiveness of such policies. Review of empirical studies on rebound effects suggests that these effects according to time and place and effect of different environmental variables can be large or small, however, this effect has been identified and proven. In addition, variety calculation and extraction of different numbers in the field reduces the range reliability. One of the ways calibrate this effect for policy makers, expansion scope publication of empirical studies in this field and used of various computational methods.
The main objective in this study provide models that based on theirs can estimated rebound effects of improving efficiency of gasoline and diesel fuel consumption in road transportation sector of Iranian provinces. For this purpose, three definitions for estimating the direct rebound effect is expressed. Because Iran is faced with extreme limitations of data such as vehicle efficiency and demand for useful work, in this study, to obtain direct rebound effect, has been used own price elasticity of energy demand. In addition to determine exact effect of fuel prices on consumption, has been used of two types of fuel common in the road transport, gasoline and diesel fuel in two separate models with two-stage GMM for data of 30 provinces (except the Alborz Province) during the period 2004-2014. Moreover, is used of per capita income, substitution commodity price, population and number of vehicles in the models.
First to the existence of spurious regression in models, it is necessary to be investigate stationary variables used in the model and also cointegration between variables. Evaluation calculated statistics and their acceptance probability indicates that gasoline and diesel fuel consumption and Gasoline-fueled vehicles in the level are stationary, but other variables by once differencing became stationary. Also results of Kao cointegration test indicates cointegration between variables. So long-run equilibrium relationship between variables and absence of spurious regression model, in both models will be verified. The results of an accurate diagnosis of models; Sargan test results confirmed validity of instrumental variables. Arellano and Bond test results indicates presence of first order autocorrelation and rejected second order autocorrelation in error sentences of first difference and thus there is no bias in estimation models. Wald test results indicates validity and significance of all estimated coefficients. The results show that direct rebound effects from improving of gasoline and diesel fuel consumption efficiency, is 6 and 2 percent, respectively. In other words, 6 and 2 percent of potential savings re-used, and 94 and 98 percent of the remainder is stored.
In this study, according to the scope of particular time and place that selected and it can be argued that price policies not could well be caused change in fuel demand. Because if the highly fuel cost per kilometer, in this case removal of fuel subsidies, is a more effective method in reduction fuel demand. But now that distance traveled by vehicle not be sensitive fuel cost per kilometer, Fuel economy standards, is not a more effective method in reduction fuel demand. And it is recommended to evaluate environmental performance standards, be used of clean alternative fuels and increase investment in fleet renewal. Because in this case efficiency obtained, efficiency will be stable.

In all countries, banks have been played a major role in financing and providing financial services in the economy by granting loans and accepting deposits. Therefore the bank’s efficiency is One of the most important issues in an economy that has to paid much attention. In some cases, mergers are common methods to increase the efficiency financial institutions and it is one of the ways of restructuring banking and financial institutions as well.
The purpose of this paper is to study of impact of x-efficiency in cost reduction in the post merger of banks in Iran. Studies show that economies of scale and x -efficiency are the main reasons for reducing the costs of mergers. The studies show that variations in X-efficiency dominate scale, product mix, and branching efficiencies.
In this paper Melat Bank and Tejarat Bank with the most assets in between Iranian bank was selected and mergers was simulated.
We estimate a translog cost function across the sample, then use this function to simulate mergers between pairs of banks by comparing the sum of predicted costs for a given pair of banks with the predicted cost of the merged entity. it is assumed that the hypothetical merged bank is simply the aggregation of the two individual banks thus the total asset and loans are consolidated where input prices are taken as the mean of the input prices for the two individual banks.
The x-effeciency is estimated in hypothetical mergers by using balance sheet data banks that were merged hypothetically in the periods 1382-1393and by using the Translog cost function and SUR metod, the impact of x-efficiency and omitting branches were studied on reducing costs in banks that were merged hypothetically and was compared changing costs through x -efficiency and omitting branches.
Data included: three outputs and three inputs .the output contains a variety of loans to commercial and industrial and other loans, such as loans granted to agriculture, export and services sector and investments , inputs included the price of physical capital and interest paid on deposits , price of labor and average assets.
we assumed that the degree of X-inefficiency of the merged banks would equal the asset –weighted mean degree of X-inefficiency of the unmerged banks and the mean residual of the two banks was added to the predicted cost of the combination, and this sum was compared with the sum of actual costs (predicted plus residual) of the two unmerged banks.
To distinguish the relative impact of branching, and X-efficiency,these simulations were run under alternative assumptions about the number of branches closed following a merger therefore was omitted ,zero, 10,20 ,50 and 100% of the smaller bank’s branches.
The simulation technique provides a forward-looking picture of what the market could reasonably believe about the potential cost effects of mergers, based on ex ante financial information. Such analysis is useful in predicting patterns of mergers, to the extent that future consolidation will be influenced largely by cost considerations. The simulation technique can also be applied to a much larger sample than ex post merger studies alone; this is important not only for enhancing precision, but also as a way of addressing the concern that many unmerged banks (that may merge in the future) may differ systematically from banks that have recently merged.
The results show hypothetical merger between the two banks, due x- efficiency reduced costs but the omitting branches can not reduce the cost of the merged bank, In other words, the merger of the two banks, by the x-efficiency reduce costs of the merged bank.

Misuse of water, a reduction in average rainfall and Climate Change has been decliningthe country's water resources in spite of fluctuations in different years. In addition, the ministry of energy despite the high costs involved in the extraction and distribution of water to different sectors, including agriculture, always receives very low and similar rates from all provincial farmers and they do not pay any money for removal of wells. In recent years, the discussion of "virtual water" and water content products in the form of "green water", "blue water" and "gray water" attracted the attention of many researchers of water.
Now cropping pattern is determined by the goal of maximizing the area under cultivation. The water content products are various in different regions with different agricultural products. In addition, the process of global warming has caused the country's water resources in spite of fluctuations to decline in different years continues. Therefore, farmers should determine the production rate of crops in different areas by goals such as water efficiency. They should aim to maximize water efficiency and should be replace it as an alternative to maximize the acreage or maximize their performance. The question of this study is determination of economic value of virtual water according to water content and water efficiency products?
Our review sample includes a selection of the provinces that have the status of "severe water shortage", "water shortage", "water stress" or "tolerable" are based on the classification of the water balance of the ministry of energy. Thus, the five provinces of Ilam, Bushehr, West Azarbaijan, Esfahan and Semnan were selected for this study. Products are divided into five groups of crops (cereals, pulses, industrial crops, vegetables and cucurbits), and among them 12 are selected products whose information has been registered in the Ministry of Agriculture Jahad. To evaluate the aim of this study, a pattern of fuzzy linear programming (FLP) is used. The results show that: (1) The economic value of blue water (total surface and groundwater) of West Azerbaijan, Bushehr, Isfahan, Semnan, Iran Ilam provinces according to maximizing water productivity are 14615, 40608, 7240, 4673 and 39274 Rials per cubic meter of blue water, respectively. (2) The economic value of gray water (water from sewage treatment) for West Azerbaijan 7220 and for Isfahan is 8330 Rials per cubic meter of gray water. In general, the provinces have more bad water situation, the economic value of water content of their products is higher. (3) water productivity of 12 crop were increased in selected provinces. So that, it increased in Semnan province of 0.14 to 8.13, 0.02 to 0.04 Isfahan, West Azarbaijan province from 0.12 to 0.29, Ilam province from 0.34 to 5.29 and in Bushehr province from 0.62 to 3.53.
Due to the results of the research, recommendations for decision-making and policy-makers in relevant fields provided. (1) policy agricultural production in order to conserve water resources shall be directed to give priority to crops that while increasing water productivity of agricultural products is in line with the virtual water content. (2) According to the results of the economic value of water content is different crops in different provinces. So the government for the proper distribution of water in agriculture in different provinces with different prices. (3) According to different economic values ​​for the water content of crops, the price of finished agricultural products are blue in the provinces where the situation is different, be different. It seems to be in determining the final price of agricultural products and guarantees, the value lies in their virtual water content of the reform.

Some subjects such as economic growth, optimum distribution of national income and also economic justice have been considered by the economics and economic policies in Iran. In this regard, there are a variety of ideas about the interaction effects of distribution of incomes and eeconomic growth. According of the foundations of theoretical, there is a U reverse relation between distribution of national income and economic growth. This curve in known as Simon Kuznets hypothesis in economic literature of growth. Some different result have been obtained about the relation between economic growth and income inequality based on several studies in Iran and out of Iran. According to doing the law enforcement targeted subsidies in Iran during recent years, one of the most important goal of this plan was to improve distribution of national income among the poor layers of social.
In this regard, this study aims to evaluate the relationship between economic growth and income distribution during 1350-1389 in Iran. For this purpose, Gini index for income distribution measurement and autoregressive logistical approach or methodology smooth transition logistic smooth transition auto regression (LSTAR) is used as the econometric approach. In this method, the relation between variables is changed nonlinearly. So, first the problem is modeled nonlinear. According to the number of observations that are less than 100 observations, Schwarz- Bayesian criterion is used to in order to finding the optimum amount of lag. Based on this criterion, the optimum amount for both dependent and independent variable is 1. Based on result about estimation the model and rejection two hypothesizes and and, the model of LSTAR1 is selected. Next results show that gross domestic product (GDP) growth has a negative and significant effect on Gini index as a criterion for measurement income distribution both in linear and nonlinear cases in the period under review. Non-linear relationship between these two variables shows that the optimal level of the Economic Growth involves maximizing Gini coefficient in Iran. On the other hand, more increasing in Gini index means shows more unequally in income distribution. Therefore adoption and deploying polities for increasing growth economic will cause decreasing Gini index and more equally income distribution in Irani economic. This result also show that, the hypothesis of Kuznets about existing a nonlinear relation between economic growth and income distribution cannot be rejected.
In order to evaluate the nonlinear estimated model some tests were used such as ARCH- LM test, lack of autocorrelation, and stability of parameters. This evaluation was done by using the JMULTI software. The results of evaluation confirm that there is no error relevant to existing autocorrelation in none of lags. This result show that there is no autocorrelation in variable lag of the gross domestic product (GDP) growth in Iran economic.
Additional analysis show that there is no other nonlinear variable in the estimated model and so, the null hypothesis about suitable specification of the model cannot be rejected. Also in order to evaluate the dissimilarity of variance between disturbances of the estimated phrases, the Auto Regressive Conditional Heteroskedasticity Lagrange Multiplier (ARCH-LM) test was done. The result of analysis in this section presents that the hypothesis of absence of dissimilarity of variance between disturbances of the estimated phrases, cannot be rejected. Additional analysis confirm that equality of the coefficient in linear and nonlinear model is rejected. Finally the Jarque-Bera test confirm that the disturbance phrases have a normal distribution.
The basic results of this study have a good compatibility with foundations of theoretical and also the result of studies of Uge Panizza (1999), Rafael Gomez & David K. Foot (2003). Angles – castro, Gerardo (2006), and Ben – David Nissim (2007).