Income Distribution is usually affected by social and economic structures and especially by factors such as inflation, unemployment rates and the government size. In addition, the level of literacy and education are also seen as important factors affecting the Income gap among different groups. The purpose of this article is to study the relationship between educational variables, measured by the literacy level and its dispersion, and Income Distribution in the Iranian economy for the period 1347-1380 (1968-2001). Our findings indicate that as the average level of education increases, Income inequality will decrease; but with increasing the standard deviation of education among citizens, Income equality worsens.

Income tax does have allocative and distributive roles in economy. So, one of the key roles of Income tax is distributive. The major principle of this type of tax is "justice principle". This paper uses a modified version of the Engel, Galetovic and Raddatz model to examine the effects of salary tax on the Income Distribution in Iran.The findings of the paper confirm that the optimal tax rates in Iran are 25.18, 28.28, 12.5, 12.5, 12.5 percent, respectively, over the period of the third five-year development plan. Comparing the actual tax rates with the optimal ones, it is observed that there exists a significant gap between potential and actual tax rates in the country.

In this paper, to evaluate Income and Distributional effects of Personal Income Tax, a hypothetical society is simulated.12 Income sources are defined that each member of society can earn Income from one Income source or more. Then, using FORTRAN programming, the government's tax Income, Income Distribution and average tax rate are calculated, assuming five alternative Scenarios: 0. Base scenario: taxing personal Income at source according to "Direct Income Taxes Act"; 1. taxing the sum of Incomes each individual person earns from different businesses he or she owns and exempt his / her business Income once; 2. taxing the sum of Incomes each person earns from non-exempt sources and exempt his / her business Income once; 3. taxing the sum of Incomes each person earns from exempt and non-exempt sources and exempt his / her business Income once; 4. qualifying third scenario by accepting a 1 billion Rials as exemption. Results of simulation indicate that the government's Income and Income equality is maximized in 3rd scenario.

One of the most important objectives of implementing social security systems is Income reDistribution and poverty alleviation among the members of the society, that is accompanied with other policies to improve Income Distribution.Among different strategies of social security, social insurance has a special priority and covers a large share of the society. Since old age and disability is certain to occur in everyone's normal life, therefore the issue of pensioners' Income is important for both pensioners and the society at large.This paper uses the household budget survey of the Iran Statistic Center to study the households with a pensioner head and to compare this group with urban households, using Distribution measures and indices.The results show that, in average, headcount ratio between households with a pensioner head is less than the urban households.The annual per capita expenditure in former group is higher than the latter one, and are not Income Distribution between pensioners improved in years, but results show a better situation for urban households.