Tax , as the most initial and most important public revenue , principally plays an important role in providing public expenses and for this purpose, it enjoys an extraordinarily higher place for all states in the world.In this way in Tax laws that are currently enforced in all states including Iran, special rights and powers have been granted to Tax organization in order to allow it to carry out fully well it’s tasks and liabilities in this enterprise. These rights and powers are called as ‘Tax authority exercise’ Nevertheless, today emphases are more laid on the motivated involvement and co-operations from Tax payers than exercising any authorities and rights of these kinds. the example of which is already followed by Iranian Tax law outhorities.Farther consideration of the case as mentioned above show that Tax is counted as one unique manifestation of a state’s sovereignty and is best mixed with its authoritative continued existence.

To develop and survive in the modern competitive environment, all governmental/non-governmental organizations do need effective system of performance assessment enabling them to measure the efficiency and effectiveness of their organizational programs and processes, and resources. Efficient organizations do not suffice to gathering and analyzing data, but rather, they try to make use of data for achieving to their intended missions and strategies. In other words, instead of resorting to performance assessment, they involve themselves in performance management. According to what was said, Zanjan province Tax affairs Office, as one of the most impartment administrative divisions of in Zanjan Tax affairs(INZTA),is required to change itself with other divisions of INZTA and to change itself in accordance with the stakeholders expectations thorough administrating pre-determined strategies and assessing its overall performance. This research explains applying Balanced scorecard for functional evaluation in Zanjan province Tax administration. After gathering indicators a mount with mentioned methods, it is indicated that Zanjan Tax administration has not developed balanced while major efficiency of current strategies is through increasing Tax income.

Governments always are trying to enforce new Tax laws and ways to find a solution for deficiency in Tax revenue. The success of any Tax system is highly dependent on the performance of the Tax organization. From 1384 the discussion about calculating a separate Tax on oil company was introduced. The calculation of Tax effort rate had been fluctuated with respect to this change. Thus providing a model that can minimize these fluctuations is required. Recently, new techniques are used to evaluate the performance of the organizations of which data envelopment analysis is the most innovative one. In this study, Tax administration has used basic DEA models and the Gini index and receivable income was selected as output and current costs were selected as input. Research period is from 84 to 90. The results indicate that Tax organization's performance without oil company Tax is in the most efficient level in the years 87 and 90, and it is locally efficient in 86 and 88. Furthermore when calculating Tax organization's performance with respect to Tax on the oil Company in the year 87, it worked in the most efficient size but it is efficient locally in the years 86, 88. The results show that in these seven years the relative calculated efficiency by DEA has very little sensitivity to calculation of Tax on Oil Company or lack of it on organization's receivable income.

The type of company (service, manufacturing and commercial) submitting Tax return transcripts within the specified time in the six Tehran’ s Tax affairs districts (north, south, east, west, center and large Tax payers) influences the rates of intention-to-pay Tax and the present study tries identifying the companies’ function in terms of changes in four (economic, structural, behavioral and regulatory) factors influencing Tax payment. As a qualitative-quantitative research, interviews were seminally made with the corresponding experts and elites and factors influencing the intention-to-pay Tax, including the four abovementioned factors, were explored. A questionnaire was next designed by the researcher in two parts, general and specialized, containing 108 items. The instrument validity was investigated based on face and content validity tests. The study population included legal Tax payers (companies) in the six Tax paying districts in Tehran in 2016 and 382 companies were selected based on Morgan’ s table and relative stratified random sampling. After collecting the data, internal consistency test was conducted using Cronbach’ s alpha method. Kruskal-Wallis test and Mann-Whitney U-test was applied as a follow-up test to analyze the data. The results indicated that there is only a significant difference in terms of economic factor between the Tax payers, in separate by company type, and that there is also a significant difference between service, manufacturing and commercial companies (P<0. 05).

The country's Tax system consists of various components, the analysis and analysis of each of which will lead to the promotion and increase of the efficiency of the Tax system. The process of collecting Taxes in the country has generally started from finding a unit and the process of reviewing, identifying and determining Taxes, and finally, by paying or protesting against the relevant Taxes, the Tax process has been completed, which ultimately leads to fraudulent government Tax collection. In this direction, there are several problems and challenges facing the Tax system from the beginning of the process to the end, and counting these problems and solving them will improve the Tax system. The method used in this study is field. The statistical population of this study includes people working in the Tax organization, the Society of Certified Public Accountants and university professors, and the statistical sample used in this study was 157 people.. The research findings showed that; Risk management in the Tax administration is affected by the risks of Tax laws, Tax litigation, Tax collection, human resources, information technology, administrative health, risk - based auditing, noncompliance, Tax incentives, Tax evasion, Tax audit quality, The quality of the Tax audit, databases, knowledge and Skills, power, relationships, and the risk of outsourcing Tax processes are at stake.

organizational Commitment has been defined as the extent that an individual accepts, internalizes, and views his or her role based on organizational values and goals. The three components –affective commitment, continuance commitment, and normative commitment– form the basis of a new conceptualization of organizational commitment. Job stress has become one of the most serious health issues in the modern world, as it occurs in any job and is even more present than decades ago. The purpose of this research was to study the relationship between job stress and organizational commitment in Mazandaran Tax organization's employees. Statistical population of this research included all employees (full time) of Tax organization of Mazandaran (N=243) and statistical sample was equal to (n=149). The results indicated a positive significant relationship between job stress and organizational commitment, affective commitment and normative commitment, but there was not a significant relationship between job stress and continuance commitment.

Since in most countries, companies take measures to evade Taxes and deceive the government, Tax collection has always been one of the main problems of governments. The main goal of this research is to provide a model to prevent Tax evasion from the perspective of the employees of the country's Tax affairs organization. For this purpose, using the theoretical foundations of the research, factors affecting Tax evasion have been extracted, which have 5 main dimensions (economic factors, social factors, legal factors, internal organizational factors, and cultural and political factors) and 20 sub-criteria. These factors have been collected from twenty Tax experts and experts using the fuzzy Delphi method. The obtained results indicate some of the most important factors of Tax evasion, which are, respectively: weakness in clarifying the Tax law and contradictions in the legal provisions of Taxes, lack of efficient promotion of Tax culture, political trust, corruption of government members, and administrative bureaucracy. and the inefficient Tax structure, considering the Tax system to be fair to the Taxpayers, the lack of Tax belief among the people and the Taxpayers' lack of trust in the government, economic crises, the absence or weakness of effective supervision and follow-up in the process of Tax recognition and collection, the expansion of jobs Fraud and underground activities, the ineffectiveness of the Tax incentive and punishment system and mechanism, the weakness, extension and complexity of the laws and regulations related to Taxes. Finally, a model was designed to prevent Tax evasion from the perspective of the employees of the country's Tax affairs organization.

Todays, the importance of Taxes as the main source of government revenue has been approved by economic policymakers and therefore, designing an optimal Tax system to achieve this subject is essential. Governments are looking for ways to receive their target Taxes from Taxpayers at the lowest possible cost and at the declaration Tax. Taxpayers, on the other hand, seek to postponed their Taxes as much as possible and make the most of the effects of inflation. This paper models the game between Taxpayers and Tax affairs organization. The results show that the Nash equilibrium in the designed game occurs where Taxpayers declare their declared Tax less than the diagnostic Tax and careful handling by Tax affairs organization. In the next step, the equilibrium is somewhere that Taxpayers continued their protest until the step of the Court of Justice (the dominant strategy) and Tax affairs organization agrees with them (the dominant strategy). Finally, the optimal fine rate for the Tax affairs organization was determined until Taxpayers do not continue their protest to buy time and devalue the amount paid and agree at the initial stage 238.

According to the definition, efficiency is the ratio of outputs of an organization to its inputs for which there are parametric and non-parametric ways of calculation. In non-parametric method which forms the base of calculations in this research, efficiency is evaluated through a series of mathematical optimizations. In this research Tax organization of each province is considered as a decision maker unit which posesses several inputs and outputs. In order to compare the efficiency of different provinces of the country, they are divided into two groups on the basis of their stages of development and their shares in total Tax payments. Efficiency of Tax organizations of provinces is measured by using Data Envelopment Analysis procedure (DEA), and the results show that in a period of 2005-2006, there has been an Average efficiency of 73% for developed provinces and 89.5% for less developed provinces. Regarding the figures related to the efficiency of provinces, we consider the difference between efficiency of provinces and efficiency of 100%, as their shortcoming in Tax capacity achievement. In other words, efficiency of provinces shows that they are from legal potential capacity of Tax collection. So, legal Tax potential of provinces are calculated on the basis of above mentioned figures.