فهرست مطالب amir hossein montazer-hojat

Environmental pollution is one of the most important problems that most developing countries face today, which in addition to environmental problems has negative economic and social consequences. Studies show that the shadow economy and institutional factors can be influential factors on the quality of the environment in developing countries, and few studies have been conducted on the effect of these factors on environmental pollution at the same time. The shadow economy occupies a large part of the economy of developing countries, which can affect the quality of the environment, and institutional factors can affect the quality of the environment through different channels, such as controlling and influencing the shadow sector. Therefore, the current research has been conducted with the aim of investigating the effective factors of environmental pollution in oil developing countries. Using the panel data model and the generalized least squares method for the period of 2009-2020, the results have shown that the shadow economy and the rule of law directly increase pollution and the interaction effect of the rule of law and the shadow economy has led to a reduction in pollution; Therefore, it can be expected that by controlling the shadow sector, increasing the rule of law will lead to a reduction in pollution. Also, the results have shown that corruption control has directly reduced pollution and the interaction effect of rule of law and corruption control has led to a reduction in pollution. Therefore, controlling corruption and increasing the rule of law at the same time plays an important role in reducing pollution in oil countries. Also, the results confirm the hypothesis of Kuznets for the group of oil developing countries at the beginning of the development path.

Investigating the behavior of the main gas producers due to the increasing importance of this fossil fuel is one of the most significant issues of energy importing and exporting countries. The emergence of the Gas Exporting Countries Forum as the main player in the global gas market gives importance to the analysis of changes in the members’ behavior of this forum including Russia due to the extra capacity in production. In this article, the behavior of Russia in the Gas Exporting Countries  Forum is analyzed by using Markov Switching model and monthly data from 2008 to 2022.  The results showed that the pattern of Russia's behavior in the forum does not fluctuate between competitive and collusion regimes over time. so that Russia's behavior in the first regime has been non-competitive and based on the pattern of "partial market sharing" and the Second regime it's behavior  has been non-competitive  based on the pattern of " Market Sharing and Price Making ".   And Russia's behavior in both regimes has been non-competitive. On tne other hand the results showed that Russia's average stay length in the first regime is 18/19 months and in the second one is 27/15 months.

Fiscal decentralization refers to the transfer of responsibility and authority of revenue and spending decisions from the central government to lower levels. In recent years, with the increase in energy consumption, global warming, carbon emissions, and climate change, the issue of fiscal decentralization and its environmental effects has received attention. Because fiscal decentralization has an important effect on promoting clean energy sources, reducing energy consumption and reducing carbon emissions. In the present study, Hybrid intelligent models have been used to developed to predict and analyze the effect of fiscal decentralization from two dimensions of expenditure and revenue on energy consumption and its environmental environment by combining particle swarm optimization algorithms, genetics and neural network. Controlled optimization algorithms enhance all prediction steps. For this purpose, seasonal data was used during the period 1996-2022. According to the research results, resilient backpropagation neural network in predicting revenue decentralization and Scaled conjugate gradient backpropagation neural network has a high power in predicting expenditure decentralization in the country. Also, the value of R statistic, which indicates the goodness of fit of the model, has the highest value for the revenue decentralization variable compared to the expenditure decentralization, and this indicates the better performance of the revenue decentralization model than the expenditure decentralization. The results of the combination optimizer model (GPA) and the neural simulation model (GAPSO) in predicting the decentralization of expenditure and revenue showed that the decentralization of revenue had the best performance compared to the model of decentralization of expenditure. 

South Pars_North, The existence of the Dome gas field and the common membership of Qatar with Iran have given importance to analyzing Qatar's asymmetric behavior productively in the world gas market. Qatar's position in the world gas market and its excessive capacity in gas production provide an opportunity for an increase and decrease in the production of natural gas with changes in variables such as other members of the gas exporting countries production, shale gas production, world natural gas demand, world natural gas price, and the crude oil world price don't change to stabilize a systematic and aligned market. This paper investigated Qatar gas productive behavior using seasonal data from 2001 to 2021 and the autoregressive distributing (ARDL) method. The results showed that during changes (increase and decrease) in the mentioned variables, as the most important variables affecting the formation of changes in the supply and demand of world gas, Qatar Gas's productive behavior in the direction of aligned market stability will not change. And in the global gas market, Qatar shows similar behavior to Saudi Arabia in the worldwide oil market. Also, empirical results showed that in the long term, there is a significant relationship between Iran and Qatar gas production. By increasing Iran's natural gas production by one percent, Qatar's natural gas production will increase by less than one percent

Health is one of the issues with a great significance for all members of a society. People always try to protect themselves from harmful effects of pollution; hence, the averting behavior on their part. The present study has tried to estimate the net potable water pollution averting expenditures for citizens of Ahvaz.   

A multinomial logit model was estimated where the water quality parameters (color, odor and taste) were introduced in order to account for both direct desirability and health retention-induced desirability at the same time. In this study, averting behaviors included buying mineral water bottles, commercial treated water containers, and mounting a domestic water treatment system. The respondents’ socioeconomic features were controlled. Awareness of the status quo or a person’s prior experience with tap water pollution was introduced as the perceived risk variable.  

The results showed that the individuals’ willingness to [pay for tap water replacements were 1350, 1105, and 382 thousand Rials for mineral water, commercial treated water containers, and home water treatment systems, respectively. Additionally, it was found that expenses made for mineral and home- treated waters overestimated the averting costs. Figures obtained for annual net averting expenditures were 1890, 1548, and 534 billion Rials for mineral water, commercial treated water, and home- treated water, respectively. Summing up those three figures, the overall net averting expenditures were 3972 billion Rials which indicated the imposition of a huge cost on the society. 

The obtained figure can be used as a basis in cost-benefit analysis of water treatment plant improvement projects in Ahvaz, as well as payment of environmental subsidies.

Changes in the information contained in the financial statements of companies is one of the most important sources of information for decision making for users of financial statements. The greater the range of changes in the items in the financial statements, the higher the information risk or entropy of the financial statements. When the entropy of financial statements is high, users of financial statements become confused and financial analysts are not easily able to estimate the future of the companies; therefore, the entropy of financial statements is considered as a degree of uncertainty in order to predict the future status of the companies. Investing in the stocks of those companies that have high entropy has a high risk, and due to the high risk and the possibility of bankruptcy, it is possible that the principal and profit of capital are lost. For this reason, when investors intend to invest in such companies, are exposed to information risk, And this makes investors adjust their expected rate of return. Failure to meet the expectations of investors will cause them to flee the stock market; This has a significant effect on the cost of capital and the actual return on shares of companies, Therefore, the purpose of this study was to investigate the effect of entropy of financial statements on stock returns and the moderating role of abnormal audit fees on the relationship between entropy of financial statements and stock returns.

The current research is applied in terms of purpose and regression correlation analysis in terms of method. The data required for this research have been collected from the website of Tehran Stock Exchange, databases and references to basic financial statements and the Notes to the financial statements of the surveyed companies. To achieve the purpose of the research, 94 companies listed on the Tehran Stock Exchange during the period 2013 to 2020 were examined. Combined data analysis and multivariate linear regression were used to test the research hypotheses. Also, we used Microsoft Excel version 16 and Eviews version 9 to analyze the data and extract research results.

The research findings show that the entropy of financial statements (general entropy, Shannon continuous entropy and Renny continuous entropy) has a negative and significant relationship with stock returns. In other words, with increasing entropy of financial statements, stock returns decrease. Also, the research findings indicate that the abnormal audit fees moderate the relationship between entropy of financial statements and the indicators used for it (general entropy, Shannon continuous entropy and Renny continuous entropy) with stock returns. In other words, an abnormal audit fee reduces the severity of the relationship between the entropy of the financial statements and the indicators used for it (general entropy, Shannon continuous entropy and Renny continuous entropy) with stock returns.

Those business units that have a higher entropy risk, their balance sheet composition has more changes. The existence of high entropy in financial statements indicates the more information risk, due to the uncertainty and instability of financial statement items in business units. In other words, investors consider the amount of changes in different items of the balance sheet and income statement compared to the previous period in order to get a correct understanding of the management's performance and their success or failure in achieving the desired goals of the business unit.Also creditors when granting loans, by calculating the entropy of financial statements of business units, If the amount is high, they refuse to give a loan due to the high risk and the ambiguity of the return of the principal and the guaranteed interest of the credits, which causes restriction in the External financing by business units. in other words, entropy of financial statements increases the risk of information and consequently discourages investors and creditors in their decisions to invest or lend and leads to a decrease in stock returns. On the other hand, Audit quality is effective on stock returns through increasing the quality of financial statements and information transparency of business units. Also  abnormal audit fee as a measure of audit quality improve the quality and credibility of financial statements as one of the most important sources of information for users of financial statements and lead to reduces the intensity of the relationship between the entropy of financial statements and stock returns and this means that investors and creditors and other users of financial statements consider the auditor's fees to be caused by other factors (other than economic dependencies) and in their opinion, the company's information is a Good support for evaluating the stock price.

Since 2004, dust storm has become a major problem in Khuzestan province, and the need for attention and action to solve this problem has increased. For this reason, the tree planting of the acute centers of fine dust to control this phenomenon was placed on the agenda of the organization of forests, pastures and wetlands of Khuzestan province.

In this study, using cost-benefit analysis, the tree planting plan of acute origins of Khuzestan province was evaluated from an economic perspective. For this purpose, the benefits of the implementation of this policy were considered as a reduction in heart and respiratory diseases, which was compared with the current value of planting and tree planting costs.

The results of this study showed that the criterion of net present value (NPV) is positive and the ratio of benefits to costs (B/C) is greater than one.

according to the obtained results, the implementation of this policy has an economic justification.

Tax evasion is one of the main activities of the informal sector of the economy and is one of the most important issues and problems of the tax system. Given the fundamental role of tax evasion in reducing public government revenues; Awareness of the reasons and factors determining the tax evasion of Iran's economy is important for policymakers and financial officials to control and reduce its growth. Therefore, in the present study, tax evasion during the period 1360-1396 has been estimated using the  new monetary demand function approach and the VECM vector error correction model. Then, using Bayesian econometric approach and using Bayesian model averaging (BMA) method, the factors affecting tax evasion in Iran's economy have been studied. The results of this study show that the trend of tax evasion index has been increasing during the period under review. Also, the variables of tax burden, degree of urbanization, oil revenues, unemployment rate and tax complexity have had the greatest impact on tax evasion.

In financial markets, risk management is tied to the concept of fluctuations and it is impossible to manage it without knowing why fluctuations occur. Fundamental analysis of fluctuations requires the study of very large forces in the market, and this is very difficult due to the lack of sufficient data, uncertainty about exogenous variables and the time required to study them. In this study, an attempt is made to identify the pattern of uncertainty transfer of variables affecting the long-term turbulence of industrial sector returns on the Tehran Stock Exchange. In this regard, the mixed data model (GARCH-MIDAS) and data of various internal and external variables with daily, monthly and seasonal frequencies in the period 2009-2010 have been used. In the stage of selecting variables, different models, variables affecting the turbulence of the efficiency of the industrial sector in the long run were estimated and the variables that had a significant effect on the transmission of fluctuations to the industrial sector were selected. Among the various domestic and foreign variables, uncertainty due to inflation, exchange rate, gold price and oil price have transmitted turbulence to the industrial sector in the stock exchange and in the long run. In addition, the results of the final model show that inflation is the most effective source of instability in the industrial sector in the Tehran Stock Exchange, which indicates that the capital market is more sensitive to domestic variables. According to the final model estimates, inflation, exchange rate and gold price uncertainty in the short and long term have had a positive and significant effect on industry turbulence. It is estimated

Karoon River is one of the most important rivers in the south and southwest of the country, which plays an influential role in electricity generation, cultivation of various agricultural products, and water consumption in many cities of Khouzestan province. However, despite the great importance of this river, it has suffered from inefficient management and erratic withdrawals, dams without basic studies, and inefficiency in water use in recent years. Today, there is a discussion about transferring water from Karoon springs for drinking to other provinces, which will definitely be non-optimal without considering the actual value of the river water and taking advantage of the market mechanism. All these problems are in the absence of knowledge of the true value of this river as a natural gift. This study tried to extract the indirect benefits of the Karoon River for a small part of its users, i.e., the residents of Ahvaz city, by using the economic value selection modeling method. Obviously, by involving the whole community with the benefits of this river and demonstrating its other benefits, the numbers obtained will be much larger and more accurate. This issue can be the primary goal of future research. 

A modeling technique was selected to extract the value of river characteristics, and the Logit model with random parameters was used in two simple and compound forms. There are three steps for choosing a model. The first step is to identify the non-market characteristics of the Karoon River. Then, the selection sets should be specified in the next step, and finally, the relevant questionnaire should be designed. To this end, it was sought to make the most of the experimental background of the research and select the features in such a way as to ensure the necessary compatibility. This study determined the salient features of natural happiness, biodiversity conservation, ecological function, and educational function of the Karoon River. In the third step, for each of the features, three levels were considered. The first level or base level showed the current quality of the river services. The following two levels provided the average and good river quality services compared to the current situation.Given that this study aims to calculate changes in people's well-being, a monetary option was also posed as the last question. This economic value was calculated based on the entrance cost to national parks in Iran and consulting with experts from the Environmental Protection Organization of Khouzestan Province. The prices used in this study were set at 0, 45,000, and 70,000 Rials, respectively. The required data were collected by completing the questionnaire from households in Ahvaz city in 2015. To design the modeling, five cards were selected. The method of creating the cards was to use the deficit design technique and eliminate unlikely situations in the SPLUS software. Ten different modes were chosen between the four characteristics of the river and the cost of protecting it. Unexpected situations are either a low level of the river feature with a very high conservation cost or a high level of quality with a meager conservation cost. The ten modes obtained in 5 cards had two Z and T scenarios and a basic scenario. To use the opinion of academic experts and improve the quality of the cards, some members of the faculty of environmental economics were interviewed. The cards were accordingly modified and distributed to some (randomly selected) respondents to examine their transparency and comprehensibility. After reviewing the collected cards and collecting the comments of the experts of the Environmental Protection Agency, the cards were finalized. In the present study, the RPL model was used in two simple forms and with action (compound) variables to control the heterogeneity in people's preferences. The collected data were entered into version 12 of the STATA software to estimate the variables and evaluated by the models' maximum correlation method. The results showed that all coefficients (except C3) were statistically significant in the simple model and had the expected sign. The positive sign of the coefficient of river characteristics showed that with the improvement of the river's qualitative aspects, the people's desirability increases. Also, the negative sign of the cost of protection showed that by paying for the protection of the river, people's desirability is reduced. The correlation ratio showed that the null hypothesis of all variables was simultaneously rejected at the level of 1%, and the model was of sufficient validity. 

Comparing the correct logarithm for the two simple and compound RPL models, the superiority of the compound model over the simple model was revealed. With the introduction of action variables into the basic model, the logarithm of correlation decreased from -690-38 to -57.685. Also, based on the correlation ratio of the null hypothesis, all coefficients were rejected at the level of 1% at the same time, and the composite model had sufficient validity. Based on the significance of the coefficients and their sign, the action model was superior to the base model. All the river characteristics, including the natural landscape, ecological function, biodiversity, and educational function, were positive. The positive sign of these coefficients showed that if any of the characteristics of the river had improved, the responsiveness to the baseline would increase. Also, all of these variables are statistically significant at 1%, 5%, and 10%. The price variable was significant at the 1% level and had a negative sign indicating that respondents preferred to participate in conservation programs that did not require additional costs. Therefore, the negative sign of the payment coefficient indicated its negative effect on the desirability of the individual. Based on the results, by dividing the coefficient of river characteristics by the cost coefficient in the composite RPL model, the willingness to pay the final fee for each characteristic was extracted. The willingness to pay the final exchange between money and the desired feature is assumed to be stable. In other words, the final rate represents the substitution between river characteristics and cost variables. For example, suppose the river's natural landscape improves from an unacceptable to a less satisfactory state (A2). In that case, each of the river's indirect users is willing to pay an average of 12,7810 Rials per month (equivalent to 153,3720 Rials per year). The greatest desire to pay indirect users is related to ecological performance at a reasonable level. The willingness to pay a good level of 212270 Rials per month was achieved for this river feature.To calculate the annual social benefits of the Karun River, the numbers obtained for marginal willingness to pay for all features were generalized to the total population enjoying them. The number thus obtained was a deduction of the annual social benefits of the Karoon River gained from its quality and non-market services. Therefore, multiplying the population of Ahvaz city (1450,000 people) by the combined marginal willingness to pay for all features at a reasonable level, the annual social benefits resulting from the indirect use of the Karoon River were calculated to be 1249 billion Rials. But the annual social benefits do not reflect the capital value of the river, as these benefits will continue each year and continuously for an extended period of time. Hence the numbers obtained were reduced for a long period. The real interest rate of agriculture and natural resources (20%) was used without social discount rates. The capital value of the indirect use benefits of the river was equal to 19825 billion Rials. Of course, the numbers obtained are only from the valuation of the benefits of the indirect use of the river. Obviously, suppose in future studies, other advantages of the river, both used (direct and potential) and non-used, are calculated and added to the number obtained from this study. In that case, the value of the capital of Karoon River will be more obvious. 

The results of this study can be used as a baseline study in environmental policymaking. Among them, the results of this study can be used in the economic-environmental assessment of projects that will be implemented in the riverbed or connected with it in the future. Failure to conduct such evaluations will lead to inefficient allocation of river resources and will have detrimental environmental effects such as dust.The issue of river water allocation should also be considered according to its economic value. Any allocation between water bodies by the government would be a non-optimal allocation, and the mechanism of inter-provincial water markets should be used in this regard. The results of this study can be considered a basis for determining the price of water in this market because the obtained figures reflect the willingness of people to pay for the benefits of the Karoon River. Of course, pricing and valuation methods are very diverse, and this research does not claim to be superior to other processes in the literature.This study aims to estimate the value of the indirect benefits of the Karoon River for the residents of Ahvaz city.

Green plans are among natural blessings which have many functions toward air quality improvement. On the one hand, plants moderate the air pollutants by photosynthesis; and on the other, beautify the cities. Many other functions have been found for the trees, of course, including the absorption of sound, water and soil pollutions. For this reason, in many nations, the creation of a green belt for inside and outside the cities has been set forth as a serious requirement but in the implementation of such projects, it is a must to select the species to be planted. The authors’ studies indicate that so far, no investigation has been done toward the selection of tree species across the city of Ahwaz [Iran]. This is a city with a hot, arid climate where the temperature rises to 57 degrees Celsius in the summer; and suffers from many environmental problems such as particulates and industrial pollutions. But the landscape planners in the city of Ahwaz are confused and occasionally, the expenses for planting trees are made with little efficiency. The selection of the best air pollution-reducing tree species may help policy makers toward optimal allocation of their limited resources. On the other hand, the budget allocated to the Organization for Landscapes and Parks of Ahwaz City Hall is not proportional to the economic benefits of the real interests of urban landscape. Achieving economic benefits of the best pollution-absorbing tree species may be used as a scientific criterion for optimal allocation of funds to this organization. Also, using the results of this study, the citizens’ awareness of the importance of trees is improved which could result in a more friendly treatment of landscape on their part and prevent the cutting of trees for banal reasons.
So far, many studies have been performed in various nations toward valuation and appreciation of natural and environmental resources such as parks, forests, lagoons, etc. (Juutien et al., 2011; Jenkins et al., 2010; Westerberg et al., 2010; Setlhogile et al., 2011; Cui et al., 2012; Newell and Swallow, 2013). However, to the authors’ experience, no studies have been done so far appreciating a tree species which might have the most attractive ability in absorbing air pollutants concerning the city of Ahwaz. Additionally, in most studies, the figures obtained for the tendency toward final payment have not been generalized to the overall community benefitting from the advantages; and therefore, the value of natural resources have not been calculated as a natural capital. Moreover, the contribution of natural resource functions value in the provincial, regional, or national gross production has not been considered; which is a very important factor in funds allocation and also in the movement toward national green accounting and environmental evaluation of projects.
The methods applied in this study is the choice modeling method, which assumes the individuals to have a rational behavior so that by choice, they would maximize their desirability considering the budget constraint. Therefore, it is assumed that any respondent has a random desirability function (Ben-Akiva, 1985). A random desirability function consists of a specific, observable component and a random one (Montazer-hojjat and Mansoori, 2016). A random parameter logit model would be suitable to explain such conditions:Where um is the desirability of the nth individual, a binary variable; P, the protection cost for tree species or their improvement across the city; Ai, selected quality features of the tree such as air and sound pollution absorption, providing a delightful natural landscape, and educational services; Aisocij, an action variable of socio-economic characteristics of respondents and quality features of the intended tree species. Obviously, the socioeconomic characteristics of individuals are fixed at the time of their selection among the options and therefore, they appear in the model in action form with the features of tree species. After estimating the above model, the tendency toward final payment is obtained through dividing the estimated coefficient for each feature (i) by the estimated price coefficient (1):However, an important stage of this study has been the selection method for the best air-and-sound pollution-absorbent tree species as well as the field survey method applied in this section. For this purpose, three species with the highest frequency across the city of Ahwaz, Concarpus Erectus, Albiza Lebbeck, and Eucalyptus Globulus, were selected based on the data provided by the Parks and Landscapes Organization. To select the superior species in terms of air and sound pollution absorption, the Air Pollution Tolerance Index (APTI) was applied. This index is calculated using four parameters, namely, total chlorophyll, leaf extract pH, relative water content, and acid ascorbic concentration) (Pathak et al., 2011). To perform laboratory process and calculate the APTI, the sampling process from the leaves of selected trees was performed in five highly trafficked areas, namely, north (Kianpars), south (Golestan), east (Zeytoon Kargari), west (Kamploo), and downtown Ahwaz (Amaniyeh), randomly.
Leaves from three selected species were collected in three different time frames during June 2015; and for each species in each area, three plants were sampled randomly as replicas. Coevality of the trees, given the commensuteness in diameter and length of their trunks was also taken into account. Leaves collected in frozen environment (zero degrees Celsius) were directly transported to the laboratory.
Later, relative moisture and pH of leaf extract were measured. In order to measure other parameters, collected leaves were stored in zero degree Celsius conditions so that their properties would not change. Ultimately, the figures obtained from the experiments were fed into SPSS21 software for analysis.
Discussion of Results and The results obtained from the measurement of five parameters, i.e. pH, RWC, ASC, CHL, and APTI, for three selected tree species, led to the selection of Albiza Lebbeck as the superior species in terms of air and sound pollution tolerance/absorption. The benefits of this species were also calculated for city residents. Tendency to final payment for four functions of this species was obtained dividing estimated coefficient for each feature by the price coefficient. They include tendency to final payment for natural landscape (Rials 1,418,128.4); reduced air pollution (Rials 1,692,708.9); reduced sound pollution (Rials 1,770,981); and educational performance (Rials 1,653,938.4). Additionally, the annual value of benefits and capital value of this species were calculated to be Rials 1,167 and 1,852 B, respectively.
Using the figures obtained for annual value of social benefits of Albiza Lebbbeck species, the municipality of Ahwaz will be able to direct the budget of the Parks and Landscapes Organization toward higher efficiency; and to determine its budget based on every citizen’s landscape quota and the figures obtained by this study. Additionally, the municipality may use those numbers to determine the tendency of residents to pay renovation and building license charges; and to update previous numbers.
Given the results of this study and the enormous capability of Albiza Lebbeck in absorbing and metabolizing the pollutants, it is recommended that planting this species be included in agenda in highly trafficked areas of the city of Ahwaz such as the downtown, along city roads, industrial zones, factories, and other areas where there is a possibility of air pollution. Also, by using the results of this study and the obtained figures, it is possible to improve social awareness on real value of this species’ functions, enhancing their sense of responsibility to protect it, and to prevent their unnecessary cutting. Also, the results of this study can be used as a basis to fine the breaching citizens for cutting the trees. Another use for the results of this study is in the field of economic-environmental evaluation of urban projects. The figures obtained by this study can be used to evaluate the projects which might require cutting the trees. Thereby, environmental costs will be included in calculations; and the justification for some projects might even be questioned.

Audit fee is one of the main subjects occupying both the employer’s and auditor’s minds. They must discuss the issue clearly. A variety of factors can affect audit fee, such as the amount of cash holding by firms that is one of efficient factors on agency costs. In this paper, we examine auditor’s response to determine audit fee under considering the amount of cash holding by firms. For this purpose, the required data for this research is collected from eighty companies listed in Tehran Stock Exchange for a period of six years between 2009 and 2015. The Statistical method for hypothesis testing is multivariate regression that examines the relation between cash holding and audit fee. The results of the research show that by making other factor constants, there is a positive relation between cash holding and audit fee. This relation reflects that auditor’s response to different levels of cash holdings as one of agency costs.
response to determination of audit fee under considering the amount of cash holding by firms. For this purpose, the required data for this research is collected from eighty companies listed in Tehran Stock Exchange for a period of six years between 2009 and 2015. Statistical methods for hypothesis testing is multivariate regression that examine the relation between cash holding and audit fee. The results of research show that by stabilizing other factors, there is a positive relation between cash holding and audit fee. This relation reflects that auditors response to different levels of cash holdings which is one of agency costs.

One of the important aspects of the management of wetlands in possession of various aspects of their economic value, which indicates the importance of natural resources for the residents of a region or country. In general, wetlands benefits are divided into two categories of use and non-use. This study sought nonuse value of the wetland through modeling preferences and willingness to pay is calculated and put at the disposal of policy makers and society. In this regard, using the choice experiment, the nonuse value of Shadegan wetlands was estimated. Therefore, the design and implementation of the choice experiment and completing 120 questionnaires in Ahvaz and Abadan, combined with a random coefficient logit model estimate values for wetland features include biodiversity, ecological function, educational services and natural scenary were estimated. The values obtained were extended to the whole society the enjoyment of these blessings. The results showed that all variables of the model (including wetland features and price) statistically significant at 95 percent and have expected signs. The estimated marginal willingness to pay for nonuse benefits suggest that the value of the improve the quality of each wetland features for people who wish to visit wetlands in the future is not significant. Calculations showed that the value of wetland benefits is equal to 4,303,395,852,380,952 Rials. So, by adding this value to the province's gross domestic product, the share of the wetland benefits is more than 2 percent. The numbers showed the importance of wetlands for society as well as the susceptibility of the conditions to comply with its conservation policies.

Wetlands surrounding communities have enormous benefits of this natural capital. Economic valuation study of society’s preferences for any change in the status of wetlands, can be direct or indirect interests them money and provide useful information to the planners. Bamdezh wetland is one of four large wetland with an area of ​​4000 hectares in Khuzestan province in southwestern Iran is located. In this study, using market prices for direct use value of wetland have been calculated for 2015. The interests of agriculture, horticulture, animal husbandry and fishing respectively. Also, using the model of the willingness to pay for nonmarket characteristics of wetlands, including the natural landscape, ecological function and biodiversity has been estimated. The values ​​obtained for the willingness to pay was extended to the whole of society and thus the annual value of use and nonuse values were obtained. Finally, in the absence of social interest rate and using the real interest rate in agriculture and natural resources, all the annual values​​ obtained were converted to the total value. This number was 47289 billion, equivalent to 1.9 billion dollars, which represents positive values ​​and preferences of society to protect its wetlands. So any protection program by policy makers and managers will be actively supported by the population if the level of public awareness about the values improves. The results of this study as a basic reference can be studied in this context.