Any illegal attempt to not pay TAXes, such as not giving the necessary information about TAXable income and benefits to the authorities, is called TAX EVASION, and determining the level of TAX EVASION and having a better understanding of its reasons will help in the process of finding mechanisms to prevent it or reduce its intensity. the purpose of this study is to prioritize effective factors on TAX EVASION. For this purpose, by collecting the necessary information through library method and then distribution of questionnaire in two stages, the collected data were analyzed using Fuzzy Analytic Hierarchy Process method. the statistical population studied in this study is senior managers, staff managers and active experts who have a working relationship in different units and departments of the TAX administration, among which 20 were selected as samples. To determine the importance and ranking of the main factors of the main factors and effective sub-factors on TAX EVASION, Group Fuzzy Analytic Hierarchy Process (GFAHP) has been used. The results of the prioritization of research variables have shown that the the most important main factor for TAX EVASION is the determined executive factor and the main economic-environmental and legal factors in the next priorities.

The imposition of more economic sanctions on the state and the reduction of oil incomes in recent years have directed attention towards TAX and collection of more TAX revenues; therefore, the recognition of the determinants of TAX EVASION is necessary. The decision of TAXpayers for TAX compliance or EVASION is a function of multiple variables. The “ culture” variable is a determinant of the TAX payer’ s behavior for paying or evading the payment of the TAX; and accordingly, the present work is to analyze the link/s existing between organizational culture and TAX EVASION. In terms of purpose, the present study is applied, methodologically, it is descriptive (survey), and concerning the relations between its variables, it is correlational. The companies admitted to Tehran Stock Exchange make the statistical society of this research, and eventually, 110 companies meeting some specific criteria were chosen in this regard. The data collection tool included Hofstede’ s Standard Questionnaire (1980) on the cultural organization and Craw Standard Questionnaire for TAX EVASION (1994) devised based on Likert five-value scale. Once the reliability and validity of the questionnaire were confirmed, it was handed to the top heads of the related companies and the required data were collected. The research data were analyzed using structural equations modelling. The results of the study suggest that organizational culture has a significant impact on TAX EVASION. Uncertainty avoidance and big power distance lead to the increase of TAX EVASION, nonetheless, democracy lowers TAX EVASION.

Purpose: In this study, the motivational action and planning opportunity in TAX EVASION of companies with financial constraints are investigated and also a new model is presented to identify companies with TAX EVASION. Method: The data in this study are measured through 16 models. The research period is 10 years from 2009 to 2019 for companies listed on the Tehran Stock Exchange. Data were collected through the website of the Tehran Stock Exchange, corporate financial statements and new mortgage software. R software was also used to analyze the data and fit them into 9 research hypotheses. Results: In general, this study showed that the financial crisis in companies will cause TAX EVASION in the next period. The research results also indicate that there is no opportunity for TAX planning in companies that are in financial crisis. Conclusion: The results showed that there is no significant relationship between financial constraints and TAX planning opportunity with corporate TAX EVASION; Companies in financial crisis will have more TAX EVASION in the next period; Companies that have a financial crisis and have more TAX EVASION in the next period do not have more TAX planning opportunities; There is a significant relationship between financial constraints and corporate TAX EVASION. Contributions: Knowledge enhancement of these results is considered from two dimensions. In the first dimension, attention to the economic crisis created for Iran due to international sanctions and a special look at TAX revenues and other non-oil revenues as the first revenue of the country in the budget of 1400; And the second dimension refers to the specialized issue related to TAX EVASION of some companies. The results of this study also help TAX auditors to identify companies that are evading TAXes due to financial constraints.

TAXes make up the bulk of any government revenue and provide a sustainable source of revenue. In recent years, the main focus of the TAX reform program, in almost all countries of the world, has been on VAT. But a major problem in the effective implementation of VAT, which is a nascent TAX base in countries, is the phenomenon of TAX EVASION. Therefore, one of the most basic steps in preventing TAX EVASION in the field of VAT is to accurately identify TAX interactions between TAXpayers and the TAX organization based on existing variables and laws. Therefore, in this study, for the first time, the phenomenon of TAX EVASION in the field of VAT is modeled using the game theory tool and based on the Korchen model in the field of income TAX, and is analyzed based on the interactions between TAXpayers and the TAX organization. The results obtained by mathematical analysis of the developed models indicate that with the integration of VAT audit and Income TAX audit, the rate of TAX EVASION in the field of VAT will be reduced.

To avoid TAX EVASION and hit the country's economy, VAT is needed in the country. At present, VAT is levied in 135 countries, and this type of TAX is currently being implemented in poor countries, rich countries, countries of the Middle East, and the countries of the fringe country. In order to organize TAXes and collect TAXes, it is imperative to implement the VAT in a principled way. The assessment of VAT in accordance with Article 85, the experience of different countries, the manner of implementation and the facilities needed to implement it, operational strategies to prevent the introduction of damage to vulnerable sectors, were discussed and discussed. TAX EVASION is currently taking place in the country, so it is necessary to arrange TAXes, receive TAXes reasonably and enforce VAT. Whatever the votes of the deputies on the value added TAX, according to Rule 85, they are ratified and converted into law. In most countries, most of government revenue sources are TAXed. The share of TAXes differs from total public revenues among countries, and depends on the level of development and economic structure. Meanwhile, TAX EVASION and TAX EVASION in countries have caused TAX revenues of countries to be lower than estimated, and all countries are using their efforts to reduce these two phenomena or by reforming the TAX system, Make a climb.

This study investigates the ability of TAX EVASION prediction of listed companies in Tehran Stock Exchange (TSE) by Decision Tree Algorithms. Statistical population of this study is all companies listed in TSE from 2005 to 2016. Statistical sample includes 1081 year-company. Data was analyzed by One-Way ANOVA and Decision Tree Algorithms. In this regard, research data test was done by using SPSS and Weka softwares. The research results showed that the best performances are respectively as what follows here: Random Forest, REPTree, J48, LMT, Decision Stump, and Random Tree. In addition, the One-Way ANOVA showed that differences in the efficiency of Decision Tree Algorithms are statistically significant.