فهرست مطالب سامان فلاحی

One of the most attractive fields of research in applied macroeconomics is identifying the role of different shocks in business cycles. After the recent financial crisis (2007-2008), more attention has been drawn to the financial sector to explain economic fluctuations. In this study, we examine the role of financial shocks (loan supply shock, housing price shock, and stock market shock) alongside the real and monetary shocks (aggregate supply, aggregate demand, monetary policy, and investment shocks) in Iran’s business cycles. We use the sign restrictions VAR model in order to identify different shocks structurally. Two models have been estimated using the Bayesian method and seasonal data over the time period 1370:1- 1395:4 (1991:2-2017:1). The findings indicate that the financial shocks, especially the loan supply shock, are of great importance in explaining the fluctuations of the real economy. In addition, our results show that the role of financial shock is more significant in explaining the recent recession of Iran’s economy.

Always, the problem of liquidity shortage recognized as an impeding factor for economic development in Iran’s economy. In most of the monitoring reports of business environment, the lack of access to the finance and high rate of borrowed resources is the top problem for firms. On the one hand, the firms demand to facilitate access to bank loan finance and lower interest cost. On the other hand, the evidence of past decades implies that this policy is a temporary remedy and can’t settle the problem of liquidity shortage for firms. This subject has been one of the most important challenges in Iran’s economic policy-making area. This research seeks to recognize the main causes of the tough financial situation in Iran’ economy. The most important causes of the tough financial situation from supply side of the credit market include the low share of non-government sector debt in the total asset of the banking system, the high non-performing loan ratio, the concentrated and disproportionate allocation of loans. In addition, the crucial causes of the tough financial situation from the demand side of the credit market are the dependence of capital structure on external funds and the firm’s high need for the working capital loan.

The banking sector has vital role in flow of funds in the Iran’s economy and any defect and inefficiency in this sector can lead to serious distortion in other sectors. On the other hand, banking activities face intrinsically different kinds of risk, and the credit risk is recognized as the most important one. The main goal of this study is to identify and explain the internal factors influencing the bank’s credit risk. Non-performing loans to total loans ratio is used as indicator of credit risk. The empirical evidences have been generated based on a panel data analysis in a sample of 17 Iranian banks during 1385 to 1393 period. The findings imply that the internal factors have a significant role in explaining the non-performing loans of banks.

The credit portfolio management and the optimal credit portfolio selection are identified as one of the most effective factors in banks’ credit risk. Two main strategies in this regard include diversification versus concentration. In this study, at first, the status of diversification of Iran’s banking sector is analyzed, then the relationship between diversification of the credit portfolio and credit risk is considered. It should be noted that in order to measure credit portfolio diversification two set of naive indexes and benchmark (distance) indexes is used. The empirical evidences have obtained through a panel data analysis in a sample of 16 Iranian banks during 2006 to 2011 time period. The findings indicate that increase in credit portfolio diversification lead to increment in bank’s credit risk and this relationship is independent of the type of bank ownership.

Introduction & Study of bone quality before treatment is very important. The aims of this study were to assess bone quality with density values obtained by cone-beam computed tomography (CBCT) and to determine the correlations between bone density and primary stability of dental implants. In this experimental in vitro study 32 implants were inserted into fresh sheep bone. The bone densities of implant recipient sites were determined by CBCT. The maximum insertion torque value of each implant was recorded and stability was measured by Osstell. Spearman’s correlation coefficient was used to evaluate the correlations among the variables. The mean density value، insertion torque، and Osstell value were 1481. 78? 166. 614، 74. 69? 16. 33 and 73. 78? 4. 025 N/cm2 respectively. Statistically no significant correlations were found among the variables. The bone quality evaluated by CBCT showed no correlation with the primary stability of the implants.

One method to increase the performance and efficient use of hospital resources is using tools of economic analysis such as production function. The aim of this study was the estimation of production function among public hospitals of Kermanshah University of Medical Sciences during 2001- 11 using Cub Douglas production function.

The data about the dependent variable (number of hospitalized patients) and explanatory variables (numbers of active beds، nurses، doctors and other staffs) for six public hospitals during 2001- 11 were collected using information form. The Data was analyzed employing Eviews software version 6.

The production elasticity and the marginal production for all inputs were positive. The marginal production of active beds، doctors، nurses and other staffs were 76. 7، 73. 7، 19. 3 and 6. 7 respectively. The results also showed that the return to scale was increasing and the total input coefficient was equal to 1. 45.

The maximum of elasticity and marginal production belonged to the active beds. This implies that the hospitals administrators in response to change demands can use active beds more than others inputs. Besides، the marginal production of other staffs was less than other studies، so incentive policies for effective and efficient use in hospital resources will be essential.

The experience of large budget deficit in either developed or developing countries during the past decades have gradually led to the importance of assessing the fiscal stability and sustainability in economic literature. The fiscal stability lead to the feasibility of expenditure on public goods needed for economic infrastructures that provide long-run economic growth. In contrast, the fiscal instability of government results in variability in the necessary public expenditure that weakens long-run growth. In that case, notice to effective factors in government’s fiscal stability is necessary. Since the adaptation of VAT is one of the most remarkable events in the evolution of tax system in the past decade, in this study the effect of VAT share in total government revenue on fiscal stability will be examined. The volatility of budget deficit is used as an indicator for fiscal instability of government. The sample in this study includes 108 countries during the period 1990 to 2010. The empirical evidences obtained through a static and dynamic panel data analysis imply that the increase in share of VAT in total government revenue cause reduction in the volatility of budget deficit.

Corruption affects government finance and inflation tax level in different ways. According to the Optimal Government Finance Theory (Phelps, 1973; Helpman and Sadka, 1979), government as a rational agent uses different revenue sources to the extent that the total distortion effect of its financing is minimized. To achieve this, the marginal cost of inflation tax should be equal to the marginal cost of direct and indirect taxes. We expect that for an economy with high levels of corruption, ceteris paribus, the marginal cost of direct and indirect taxes is relatively high compared to the marginal cost of the inflation tax. A sample of 110 countries has been used to extract the empirical results. The main results have been obtained through using the Control of Corruption Index (CCI) for the period 1996- 2009. The empirical findings support our hypothesis. A higher level of corruption results in higher inflation tax. In order to check the robustness of our results, the main hypothesis has been examined by using Corruption Perception Index (CPI) for the period 2001- 2009. The results are the same. Moreover, the findings show that the effect of corruption on inflation tax is greater in developing countries.

In public sector economics, government intervention in the economy is generally justified on the existence of market failure. Government intervention means providing public goods. Financing public goods means taxation. Based on the theory of public choice in which citizens take part in elections to vote on the amount of public goods and taxes, we develop a model that analyzes the effect of democracy and corruption on the desire of taxpayers to pay taxes via the information that they convey about the quantity and quality of public goods in the utility function. Our theoretical analysis contends that desire to pay taxes is lower when corruption is higher or democracy is lower. Furthermore, it contends that the effect of corruption is stronger. Our empirical findings, based on a panel data analysis for 117 countries on the time period 1996-2010, support our theoretical analysis. Especially, we find that corruption is more important in the public desire to pay taxes.