نشریه اقتصاد محاسباتی
سال یکم شماره 2 (بهار 1401)

In this article, we try to examine how to eliminate poverty and inequality throughthe negative income tax system. In this study, the rate of poverty and inequality iscalculated through Kakwani poverty indicators and Gini coefficient inequality index,respectively. Negative income tax rate (0.5) for the income distance to the povertyline, is considered and the statistical sample of the study includes the cost andincome of 12961 urban households in Iran in 2018. The results of this study showthat the plan to impose a negative income tax (0.5) will reduce the povertycalculated based on the Kakovani index from 0.54 to 0.24 which shows a decreaseof about 0.55%. The Gini coefficient decreases from 0.38 before the policy to 0.17,which means a 55% reduction in inequality. On the other hand, to completelyeradicate poverty in Iran, according to the data of 2018, there must impose anincreased tax rate of 60% on the income surplus of non-poor people up to thepoverty line.

The main purpose of this article is to investigate the return of scale indicators,technological changes and productivity growth rate on the cost in Shazand CityWater and Wastewater Company. For this purpose, based on repetitive seeminglyunrelated Regression, translog cost function form was used to estimate water supplycost function. Cost function parameters were estimated from seasonal time seriesdata over time period 2008 to 2018. The company used four factors of production,labor, capital, raw materials and other services in the production process. The resultsshowed that there is a diminishing return to scale and a lack of economies of scale,which means that there is no natural monopoly in the company. Technologyprogress and productivity growth indicator indicates that cost reduction as a result oftechnology progress and productivity growth over the study period.

The aim of this study was to investigate the role of Islamic financial instruments inthe occurrence of business cycles in the Iranian economy. In this regard, theemphasis has been on Islamic participation bonds offered by the Central Bank. Forthis purpose, statistical data from the period 1992-2020 and structural vectorautoregression model (SVAR) were used. The results of this study showed that theimpetus from the supply of participation bonds as a tool for monetary policy and anIslamic financial instrument has led to the fact that the amount of business cycles inthe Iranian economy is not moderated. In fact, the results showed that the variablesof budget deficit, exchange relationship and price were the most important variablesaffecting business cycles in the Iranian economy. The results showed thatparticipation bonds could not act as an anti-cyclical policy tool in the Iranianeconomy. Considering the results of how Islamic financial instruments affectbusiness cycles in the Iranian economy, it is necessary to recognize the impact ofgovernment budget deficit and its financing.

Adequacy (efficiency) of investment is one of the most important issues in financial management. How to use the company's resources, especially internal funds, is an important decision in the conflict between shareholders and managers. By choosing the right combination of assets and liabilities, managers try to achieve the goal of maximizing the value of the company's stock. In this study, the effect of liquidity and financial leverage of the company on over-investment as well as the effect of firm size and company life cycle in this regard has been investigated. This study is an applied research in terms of purpose and a correlational study using generalized method of moments (GMM) in terms of nature. To test the research questions using systematic elimination method, a sample of 174 companies among the firms listed in the Tehran Stock Exchange during the period of 6 years in (2014-19) selected. The results showed that financial leverage has an adverse effect on over-investment and the effect of cash retention on over-investment is positive. Firm size and life cycle also affect the relationship between financial leverage and cash retention over-investment.

In this paper, the asymmetric effect of exchange rate fluctuations on the stock return in the Iranian stock market was investigated. Using a graph model, exchange rate fluctuations are measured and then, stock return is estimated by considering these fluctuations for the period between 1979 and 2021. The results of this study indicated that exchange rate fluctuations have a significantly positive effect on the stock return. In addition, this study tested the effect of fluctuations between the foreign exchange market and the stock market. Due to the low degree of simultaneous fluctuations between these two markets, investors can reduce their investment risk by allocating their capital between currency and stocks.

The relationship between causation of energy use and economic growth is one of the important issues of energy economy, which has been studied extensively. However, previous studies in Iran have ignored the nonlinear behavior of these two variables, which can be as a result of structural failures. In this research, the self-monitoring regression model of time parameters with probability fluctuations (TVP-VAR) is used to determine the inter-annual dynamics between the real GDP of Iran (oil, non-oil), electricity consumption, and greenhouse gas emissions in 1972-2014. The results show that the TVP-VAR model is used to study the dynamic relationship between power consumption, real GDP, and greenhouse emissions. In addition, analyzing the successive responses of GDP time, energy consumption, and greenhouse gas emissions to structural shocks suggests that these responses depend on the severity of GDP structural fluctuations, power consumption, and greenhouse gas emissions. In fact, the existence of a one-way non-linear relationship has led to economic growth as a result of energy use. This finding means that decision-makers should consider the fluctuations of real GDP, electric shock, greenhouse gas emissions, and the relationship between time-varying patterns of Real GDP, consumption electricity and emissions of greenhouse gases when deciding on energy policies.

Every year, natural and unnatural crises and catastrophes, including floods, earthquakes, hurricanes, fires, and pandemics, such as the new corona virus (Quaid-19), affect different parts of the world. The factor that facilitates crisis management in these disasters is the existence of an integrated chain of all components and humanitarian services, which is known as the humanitarian supply chain. The aim of this study is to identify the factors affecting the resilience of the humanitarian supply chain in the Corona pandemic in Iran. The present study is an applied goal and a descriptive-survey data collection. In terms of cross-sectional time and in terms of research variables is combined. Factors affecting humanitarian supply chain resilience in the Corona pandemic were determined through literature review and expert opinion. After identifying and confirming the factors, the weight of each of these factors was calculated using the fuzzy SWARA technique. Analysis of these factors showed that factors such as government support formulation and policy and strategy planning and capacity have the highest weight compared to the other factors.