TAX is taken into consideration as one of the important factors which playsrole in economic prosperity and societies' development through gaining revenue for governments. Iran's economy has been in inflationary recession condition for years but legal authorities don't pay attention to alter expense figures appeared in Companies financial statements, Whereas, revenue figures recognized carry inflation effect. Therefore, this situation imposes more TAX BURDEN on Companies especially ones Utilizing more various forms of long term assets in their Assets structure. This study investigates the relationship between TAX policy and Companies TAX BURDEN in inflationary conditions. Inventory and PPE level are used to measure TAX Policy effects as independent variables. The ratio of TAX expense to CFO is applied as a measure for TAX BURDEN. The data of Companies listed on TSE during 2002 to 2017 in regard to some consideration, are analyzed using GLS method (Unbalanced Panel). Results show that in Inflationary conditions, TAX BURDEN is increased when Companies acquire more PPE and inventories in the past years. In addition, lower inventory turnover strengths the inflation effect on inventory which cause higher TAX for Companies.

The BURDEN of proof in disputes between TAXpayer and TAX office respecting the income TAX is governed by special legal rules corresponding with the special character of TAX transactions on the basis of general rule of proving in the legal system. On the one hand, general rules of proving and some principles like the no obligation principle constitute the bases of BURDEN of proof rules in the income TAX and on the other hand, special position of TAXpayer and the role of his TAX return in the documenting and evidencing TAX transactions as well as sovereign and formal position of TAX office in assessment of income TAX create special phenomena respecting BURDEN of proof of factual transaction by TAXpayer or TAX office. This research is to analyse and propose a theory on purden of proof in income TAX disputes on the basis of general rules of evidence and special rules and phenomena of TAX law. The research method of this article is based on clarifying, analyzing and legal concluding on the basis of the relevant theorical foundations, general legal principles, special TAX rules, relevant laws and regulations, judicial practices and awards as well as findings of comparative law research. The research is to theorize for initiating the principles, rules for legal questions of BURDEN of proof in the income TAX cases.

Allocation of resources is affected by TAXes. In The demand side, TAXes can reduce demands through changes in disposable income. In the supply side, however, TAXes can have significant impacts on production capacity. An optimum TAX policy is one that minimizes the disturbances to economic decisions, while creates equity in TAX payments. This study first, examines the TAX BURDENs of industrial sector in Iran, and then applies a neoclassical model to calculate TAX BURDENs of large textile industries and compares the results with all large industries. Due to the imperfect market conditions in such industries, the model was based on the "mark up pricing behavior" assumption. The model was estimated using econometrics methods, and the results show that the textile industries are able to impose TAXes to consumers. This situation was later examined under production growth conditions. The results of this investigation showed that the higher rates of TAXes had no significant impact on growth of Production in textile industries. However, it should be noted that this study used only the national TAX payments as defined in TAX laws of the country and does not include other payments.

Underground economy affects important indexes such as formal GDP, unemployment, consumption, production and etc. Therefore it is necessary to identify elements and factors which affect underground economy to restrict it. Surveys and Studies indicate the size of Iran’s underground economy is high and TAXes, quantity and quality of regulations and performance of formal economy are the important factors that affect it. At the first stage, the results of estimated model indicate that the impact of TAX BURDEN on underground economy isn’t statistically significant. But there is a statistically significant positive (negative) relationship between regulation BURDEN (GDP growth rate) and the underground economy. In second stage, aggregate TAX BURDEN variable in primary model breakdown into its components: direct TAX BURDEN and indirect TAX BURDEN. Results of The model indicate impact of direct TAX BURDEN on underground economy isn’t statistically significant, but indirect TAX BURDEN is statistically significant and its relationship with underground economy is positive.In third stage, direct TAX BURDEN breakdown into its components: corporation TAX, personal income TAX, wealth TAX. Also indirect TAX BURDEN breakdown into its components: commercial TAX, excise TAX.The results of the model indicate that the impact of direct TAX BURDEN components on underground economy isn't statistically significant. But among the indirect TAX model the BURDEN components sales TAX has a statistically significant relationship with underground economy, while import TAX has not.

The main aim of this study is estimation of hidden economy and its relationship whit TAX BURDEN in Iran during the period 1966-2011. In the first stage: size of the hidden economy is estimated using Lisrel software concerning multiple indicators - multiple causes approach. The TAX BURDEN, natural sources of income, unemployment rate, trade restriction, per capita income, inflation and size of the government are regarded as the cause variables while the real GDP growth rate and demand for money in circulation are used as the indicator variables. So, the hidden economy is calculated using extra information and calibration; the time series of absolute and relative size of the hidden economy is obtained on in term of the based price in 1997. In the second stage we have estimated the effect of the TAX BURDEN on the size of the hidden economy. The first stage results show that TAX BURDEN, size of the government and trade restrictions, are the main reason generating the hidden economy in Iran while the per capita income does not have any significant effect. The results from the second stage indicate that: increase in TAX BURDEN on imports increases the size of the hidden economy and the growth of the total TAX BURDEN (definition1) decreases the size of the hidden economy. In general, the final effect of the TAX BURDEN on the size of the hidden economy is positive and significant.

By regarding the effects of shadow economy on main economic indicators, it is required to study the affecting factors and introduce approaches to prevent and reduce this phenomenon. In the literature, TAX BURDEN is considered one of the main reasons for shadow economy. TAX levy by government may be led to hide economic activities to avoid TAX payments. According to the studies, the size of shadow economy is so high in Iran and TAX is considered one of the main and effective factors. Therefore, this paper tends to address to the relation of shadow economy and TAXes (by different TAX categories) by the use of Co integration Analysis and ARDL model during 1971-2017. In the first model, total TAX BURDEN has divided into two elements, direct and indirect BURDENs, and then their effects on the shadow economy have been reviewed separately. According to the results, indirect TAX BURDEN has positive effect on shadow economy. In the second model, it has been indicated that real estate TAX, corporate income TAX, wealth TAX, export, import and services TAXes have positive effect on shadow economy’ s size in long term. All different TAX categories (separately) have positive effects on shadow economy’ s size in the short-term.

The aim of this article is to investigate the effect of government effectiveness on reducing TAX evasion in selected countries during the period 2000-2010. By using panel data econometric, TAX evasion as a percent of GDP is used as a dependent variable and TAX BURDEN, TAX morale, government effectiveness, GDP per capita, openness, the share of value added of industry and services in GDP and the ratio of urban population to total population are considered as independent variables. The results from estimated model suggest that the government effectiveness is the most important determinant of TAX evasion in the selected countries. The results also indicate that the effects of GDP per capita, TAX morale, openness and the relative share of industry and services sectors in GDP are negative and significant. TAX BURDEN and urbanization have positive and significant effect on TAX evasion.

Bovine Leukosis Virus (BLV) belongs to the genus Deltaretrovirus ,subfamily Orthoretrovirinae of the family Retroviridae comprising 3 main genes of gag, pol and env and a number of replication regulatory genes such as TAX, Rex, R III, C IV. For determination of genetic relationship of TAX gene of BLV in Iran with those in other countries fragments 927bp corresponding to TAX from four infected samples were amplified in PCR system and sequenced for determining nucleotide sequence and compared with identified nucleotide sequence of this gene in other countries.A comparison made on TAX gene in Iran with other countries demonstrated 3.4 to 7.7% variability in TAX gene, of which the greatest sequence similarity exists between sequences of TAX in Iran with USA (AY700378.1)with 96.6% similarity and the least relationship exists between sequences of this virus in Iran with Australia (AY700379.1) and Japan (AY700381.1) with 92.3% similarity.