نشریه مطالعات اقتصاد اسلامی
سال هشتم شماره 1 (پیاپی 15، پاییز و زمستان 1394)

Islamic tax system is the most efficient system and cannot be replaced by other systems. Islamic taxes are state taxes. Islamic scholars and jurisprudents have confirmed this matter. It is incumbent upon the Islamic government to collect Islamic taxes. Islamic taxes must enter directly into State National Treasury and must be spent on government current spending. Dichotomy in the tax system induces increasing tax burden and tax evasion.Rates of this system must be extended to all producs and incomes, and can be adjusted according to the conditions and situations. Islamic taxes are direct taxes. This system is based on development and prosperity. This system has effects like reducing tax evasion, increased efficiency, increased total welfare, reducing costs and non-productive activities and bringing balance. Integrating of tax system based on the principles of the Islamic system is a great need and can lead to a kind of revolution in economic system.

Reviewing the Imamiah Fiqh bases in the issue of Bay Al-Dayn, this paper tries to discuss the possibility of securitizing the debts that the Iranian government and banks owe the central bank. In addition, it tries to find out the principals that should be paid attention to in designation and usage of the Bay Al-Dayn Sukuk to conduct monetary policies. Using the content analysis and Ijtehad approach, the results show that because of the fact that there is a united ownership between government, Public banks and central bank (in other words, the Public banks and central bank are part of the government and not an independent entity), the debts that the government itself or the Public banks owe the central bank cannot be securitized. However, it is not the case when it comes to the debts of private banks to the central bank and hence they can be securitized using Bay Al-Dayn. Therefore, the first and second market for these kinds of securities are both permissible. Based on the research findings, it can be claimed that the Bay Al-Dayn Sukuk is a very suitable instrument to securitize the private banks debts to the central bank. The rationale behind this is that the structure of the Bay Al-Dayn Sukuk is very simple, costless and it does not need any transform of physical tangible goods between Sukuk stakeholders. Nevertheless, because of the limitations this instrument has, it could not be used to securitize the debts that government itself or the Public banks owe the central bank.

Although economics among the branches of social sciences, takes the most benefits from applying mathematical tools for the problems of explanation and prediction, so far has experienced lots of limitations.So in this paper we tried not only to study the historical and theoretical foundations of mathematics in conventional economics, but also to discuss the advantages and limitations of mathematical methods in economic researches. Then, in addition to the introduction of the theoretical principles of applying mathematics in islamic economics, its advantages and limitations were mentioned. Finally, efforts have been made to explain the right interaction of these two fields, providing an optimal model of the application of mathematics in Islamic economics.Results show that islamic economic is able to achieve an efficient pattern of the mathematics -based research, if some special principles such as laying away excesses in the use of mathematical methods, not aiming at formalisms, using new branches of mathematics and also other methods of scientific studies in the mathematical method be considered.

The efficient use of oil and gas resources is one of the most important issues in sustainable development and economic growth of countries, which is supported by Islam as well. More than half a century, in countries facing surplus foreign currency through the use of underground resources such as oil and gas, a fund has been established called the “National Wealth Fund”. In Iran an institution like the National Wealth Fund was established in 2010 called the “National Development Fund".Since the concepts of “development” and “justice” are interrelated, economic justice is one of the most important issues that the National Development Fund faces, because sustainable development does not take place unless the intra-generational and intergenerational justice is established in the society.In this study, according to the importance of justice, the role of National Development Fund in the realization of economic justice has been analyzed. In order to clarify the issue, the criteria of realization of economic justice are collected and the quadripartite principles for the realization of justice are assumed. As in order to take advantage of the experiences of other countries, the structure and function of the national wealth fund in Alaska have been studied.The results indicate that: first, provisions of the statute of the Fund should be changed significantly in order to achieve economic justice; second, the company of “National Development Fund” should be established for the professional management of resources and increasing the diversity in the economic performance.

Usury- free banking is the first step of Islamic banking and it is necessary to fully realize the Islamic banking components such as justice. The main purpose of Export Development Bank of Iran is to develop non- oil exports. Because of the importance of this purpose, we present an assessment criteria of justice in this bank; based on theoretical basis of justice we investigate one index. In our survey about the economic justice the observation of Hagh-Al- Mal is necessary, therefore based on this principle the identification of export advantages of different areas of the country and the policy of the bank for supporting are some important factor for sustainability and development of different areas. As a case we studied Esfahan province and by telephone and questionnaire among the bank customers of Esfahan branch we evaluate these factors. We collected the data based on the experience and knowledge of export practitioners. Then by structural equation and LISREL software we determined the impact of each economic sector on export advantages.

Methodology is one of the most important realms in every discipline such that it is regarded as the consolidation of that science. Methodology, however, cannot be separated from epistemology. Unfortunately, methodology doesnt have gain its proper position in Islamic Economics. Most of methods used in Islamic Economics are those of conventional economics without any innovation. Explaining methodology realm, in this paper, we discuss the relation between methodology and epistemology, and between object and subject as well as the relationship among experiment, reason and value. Emphasizing Shahid Sadr and Shahid Motahari opinions, we review the method on exploring Islamic economics theories. Then, we introduce justice as a basis for methodology and epistemology in Islamic human sciences including Islamic economics. Our attempt is to propose an innovative framework for methodology based on Islamic account of Justice which is named "Haq-based Harmony".