مجله دانش و توسعه
پیاپی 33 (زمستان 1389)

In present paper, first the concept of informal economy and its place in the economic literature has been described. Then the causes and factors involved in providing the informal sector was examined and the volume of informal economy was estimated. Second, the effect of inflation on informal economy was surveyed. To estimate the volume of informal sector, Residual discrepancy method was used and the volume of informal economy in urban areas in Iran economy from 1982/83 to 2008/09 was calculated. The results show the increasing trend of informal sector volume, during the imposed Iraq-Iran war. In addition, after the imposed war some fluctuation in the hidden economy has been detected. In the final part, after studying existing stationary of the used variables, the effect of inflation rate (in special groups) on the informal sector was examined by using OLS method. The results show that urban informal sector increase, if only inflation rate in the goods group grow up.

Since 2001 the adoption of Iran accounting standards has become obligatory. This study by using a sample of companies listed in Tehran stock exchange (TSE) compares the value relevance of ten selected accounting variables in two periods, before mandatory adaption of accounting standards (1996-1998) and after that (2005-2007). In this study the researchers have tried to control the effect of economic situations and omitted variables on the results of research. Therefore, two economic variables, inflation (CPI) and growth of gross domestic product (GGDP) are added to regression models of hypothesis. Also, hypotheses are tested by pooled method. Results show that, a relation between some accounting variables and stock return in both periods (before and after adoption of standards). The result of test of hypothesis of the third group indicates that there is significant decrease in adjusted R-Square of regression models in post-standards comparing with pre-standards period about five variables of total assets and its changes, operating income and its changes, book value of equity and in a model involving all variables of study, but decrease of predictive ability of net income, cash flows from operation and their changes and changes of book value of equity isn’t significant.

This study is performed in order to Study the effect of technical- Vocational Training on trainee productivity in Industrial Sector of Khorasan and preferring suitable solutions in this field. So labor productivity model was estimated for Khorasan industry in period 1985 to 2004. In this model, effects of different variables were investigated on productivity of labor, variables such as: relation of capital on labor, real wages of labor and also technical- Vocational Training and technology. Results of model estimation show that coefficient of technical- Vocational Training budget variable is 0.026. This coefficient is significant in 15 percent level and positive form of it shows that there is a direct relation between this variable and labor productivity. It means that increasing this variable cause to increase labor productivity. Elasticity of technical- Vocational Training budget is 0.363; it means that increasing about 10 percent in this variable cause to increase labor productivity in Industrial Sector of Khorasan about 3.63 percent.

Privatization is a process in which the ownership of governmental economic enterprises is transferred to private sector. According to other countries’ experiences and discussed economic theories over the past decades, privatization has improved the performance of companies and economic enterprises. In this study, financial ratios of companies were used as their performance indicators. This paper studies the function of companies that were assigned to private sector in Iran, before and after assignment. Results show that performance indicators of companies that transferred to private sector through stock exchange did not improve during the two following years after that.

Supply security of Energy is one of the main challenges of industrialized countries in recent decades. Also, it has been noted that in recent years other countries like new emergence Asian countries and Latin American countries, have understood the role and importance of energy. However, oil and gas have more importance for numerous reasons such as convenience availability, high thermal value and relative cheapness of this energy resources compare to others. In this paper, with a view of the geographical distribution of reserves and consumption of crude oil and natural gas in various regions of the world, using descriptive - analytical reasons, the reasons of political economy of oil and gas formation in the Persian Gulf region are discussed. However, after mentioning the most important reasons for the formation of political economy of oil and gas in this region, the main strategies of industrialized countries to maintain security of energy supply and combat the consequences of the geographical distribution of oil and gas reserves will be explained. The results suggest that after the oil shocks of 70’s, the main strategy for industrialized countries to maintain security of energy supply is using of diversification of supply oil and gas origins.

This study seek to examine performance of Feltham - Ohlsen (1995)valuation model at the Tehran Stock Exchange and is trying to identify relation between intrinsic company value and return. This model is trying to determine the intrinsic value of company using their book value. Statistical community of this study includes all TSE accepted companies and Statistical sample is including 37 TSE accepted companies from 3 different industry (Food and beverage industry other than sugar, Food industry and pharmaceutical products, Automotive Industry) and data for these firms are analyzed interval 1377 to 1386 using Time series-Cross sectional (panel data) regression model. Results show that the model above boldly dose’nt able to determine the intrinsic value of companies. But evidence shows that the companies that have more intrinsic value, earn more profits. According to the results of performance of this model can not completely rejected, but now using of this model in Tehran Stock Exchange is not recommended.

So far, the financial experts could not calculate independent earnings to have a necessary quality. In this case, they can reach a range of earnings, which show a more correct form of quality of earnings, of course with performing the suitable equitabilities. Therefore, the concept of quality of earnings is not a fixed defining. However, it is a relative concept that depends to its relation to points of view and attitudes. In this research quality of earnings is based a set of fundamental financial variables which has been discerned useful by financial analysts in the security evaluation. They believe that these financial variables would be used by investors in the evaluation of quality of earnings. The earnings response coefficient measure unexpected return of the market in response to the unexpected components of the reported earnings by the company that has distributed the securities. In other word, earnings response coefficient is the sensitivity of market in account to declaration of earnings. The purpose of this research is to study the effect of quality of earnings on earnings response coefficient. The results show that earnings response coefficient do not have meaningful differences in the companies that have different earnings quality (high, medium and low quality). In other words, investors in Tehran Stock Exchange do not consider the quality of earnings of companies at the time of response to the earnings changes.

The Environmental Kuznets Curve (EKC) hypothesis posits an inverted U relationship between environmental pollutants and per capita income. Recent researches have examined this hypothesis for different pollutants in different countries. However, so far a few number of EKC studies have been carried out in Iran. This might be due to the lack of reliable environmental data in this field. The aim of the present study is to investigate the relationship between environmental pollutants and economic growth in Iran. Therefore, during 4 years (2002-2006) the relationship between per capita income and per capita pollutant emission for three atmospheric pollutants (CO, SO2 and NOX) was examined by using panel data and Iran's provincial data. The results show that the two pollutants CO and NOX are N-shaped and for SO2 a U-shaped was found.

This paper proposes a structural model for the analysis of correlation between knowledge economy index and sustainable development across the world. An analytical model is devised for investigation of the role of the major factors in the process of development. The proposed structural model is calibrated using statistical data from the World Bank, and the United Nations for national economies across the world. Findings of the study indicate a significant correlation between the knowledge economy index(KEI),and the sustainable development standard (SDS) in a large sample of world economies. According to findings of the model, we could also significantly validate the relevance of Kuznet's Environmental Curve. In conclusion, it is argued that advancement of a knowledge based economy, requires an evolutionary improvement of economic environment in the course of globalization.

Education satisfies the human primary need for knowledge. It is a mean helping to meet other fundamental needs and it facilitates continuance and expedition of community overall development. Education provides required skillful labor for modern and traditional devisions and it increases the labor' skills and its production capacities. It is not olny a mean to improve current generation's income but also it helps to enhance future income distribution and other opportunities. Theory of human resources assumes that the individuals’ personal income is a function of their education and experience. So, inequality in income distribution can be traced in educational inequality. Schooling is a dynamic process enabling labor’s skill, capability, and return. Thus, it increases the personal and community income.The current study, based on theory of human resources considering income variations as a function of education and experience level, assumes that the income level is determined by two variables of education and experience. Justifying variations in individual’s personal income with respect to above theory, this research used two logarithmic and semi-logarithmic models to analyze data gathered from four types of educational systems with a sample size of 3000. Cross sectional data estimated by Eviews 5 software package applying OLS method. The following hypotheses tested and approved along with investigating their consistency with theory of human resources:Personal Income has a direct relationship with schooling.Personal Income has a direct relationship with Experience.Men's personal Income is greater than women's income in the same conditions of education and experience.Return of Education in educational sectors is larger than noneducational sectors.

Relative nullity is one of the sanctions against violating the rules of establishing the contract and is regarded as a known legal entity in the law of France. It is a situation that the legislator has considered in case of violating the rules supporting given party or parties. Hence, he gave them authority to decide about the contract themselves and as far as the beneficial party does not have any protests to the contract, the contract is correct and has its legal effects. However, if the annulment of the contract (on the due date) is assigned to the court at the request of the beneficial party; the contract, except in exceptional cases, has to be annulled from the very beginning to terminate its legal effects. Such a concept does not exist in the traditional law of Iran and we just come to see it in some texts, which are taken from western law. Owing to this fact, the said concept is unfamiliar and ambiguous in the law of Iran and exact understanding of this concept requires an independent and detailed discussion. This important task is not possible except through considering its origin. For this reason, in the present paper, we seek to clarify the definition and meaning of this entity via comparing it with similar concepts and providing the conditions for gaining an exact and deep understanding of it.

In recent years, sustainable development has been accounted as one of the most important policy goals at the global level. Many empirical studies have been carried out to determine the relationship between economic growth and environmental quality. The model so-called Environmental Kuznets Curve (EKC) was in most of empirical studies.The aim of this study is to estimate a Modified EKC (MEKC) in which development and sustain was used instead of economic growth and environment. In the present study, negative value of adjusted net saving was used as non-sustainability indicator and human development index was used as development indicator. The statistical population is 20 oil-exporting countries and the period of estimation is 1990-2006. The Panel Data method was used in order to estimate the model. Variables such as natural resource abundant, manufacturing and institutional qualities such as Rule of Law and Government Effectiveness were used as control variable to specify the model. The results show an inverse U-shaped relation between human development and non-sustainability of resources in this group of countries.

Study of price trend in Iran, showed that general level of prices is rising continually during time. An inflation situation has effect on most economic variables. Therefore investigation of effective factors and variables on inflation is important. Exchange rate and Gap in product are factors which affect inflation. In this paper the impact of exchange rate shocks and GAP on inflation in Iran’s economy with use of Hoderik Prescott filter and Kalman filter for analyzing exchange rate shocks and GAP during the time 1998:1-2007:4 in Johanson Cointegration test and VECM Model has studied. Main results indicated that, positive exchange rate shock has a negative effect and negative exchange rate shocks has a positive effect on inflation in the long run and sustainability in inflation in long run is less depended to exchange rate rather than short run. Also the Gap in gross domestic product and liquidity has a positive effect on inflation. So taking suitable exchange rate policy could be one way for controlling inflation.

In Present paper, housing has been considered as a multidimensional and heterogeneous item. Its characteristics has been considered as key elements in determination of unit price of each building unit. The aim of the Present paper is to determine the degree of importance which each charactericstics of housing has for users. There fore, hedonic price function of urbun housing in Khoramabad estimated. The result showed that area of land, social security of rigonal, skeleton, building facet, lane or street width, distance from city center, parking have positive and significant influence and age of building, number of room have negative and significant influence on housing price in Khoramabad. The results also showed that social security, in the preferences of the users, lane or street width are ranked as first to third priorities. distance from city center, skeleton and building facet are intermediate priorities. The number of room, parking and age of building are in bottom of list of priorities for users.