The purpose of this article is to investigate the effect of corruption on financial inclusion in Iran and selected member countries of the Organization of Islamic Cooperation during the period 2005-2020. For this purpose, three variables have been used to measure financial inclusion and three separate models were estimated. The results of model estimation using the System Generalized Method of Moments (SGMM) showed that at a significant level of 5%, lagged financial inclusion, the level of per capita GDP and education have a positive and significant effect on financial inclusion. Also, the impact of corruption on financial inclusion is negative and significant. At a significance level of 5%, the expansion of Internet users and mobile subscribers has a positive and significant effect on financial inclusion. The high share of women in the total population has a significant and negative effect on financial inclusion. Based on the results, it is suggested that policymakers reduce the level of corruption and increase financial inclusion by reducing wide monopolies, eliminating the rent, improving the quality of regulations and creating widespread transparency.

This study investigated the effect of firm-specific uncertainty on research & development investment; and the role of product market competition in this regard. The statistical research population includes 156 firms listed in Tehran Securities and Exchange from March 2015 to March 2022. It is used the multivariate regression models applying the dynamic panel data technique to test the hypotheses. Controlling for the endogeneity problem, it use the two-step system Generalized Method of Moments estimator to estimate the models. The findings showed that firm-specific uncertainty has a negative and significant effect on research & development investment; so, firms reduce research & development investment when firm-specific uncertainty increases, which is consistent with the real option theory. Therefore, considering the irreversible nature of R&D investment, firms reduce research & development investment under high uncertainty. On the other hand, product market competition has a positive and significant effect on research & development investment. In addition, product market competition significantly modulates the negative impact of firm-specific uncertainty on research & development investment, so leads to weakening the intensity of negative relationship between research & development investment and firm-specific uncertainty. These results are consistent with the theory of strategic growth options. According to this view, in a competitive environment under high uncertainty, firms face more pressure to survive in the market and invest heavily in research and development projects in order to gain a competitive advantage over competing firms; so, competition reduces the effect of uncertainty on research and development investment.

In this research, in order to investigate the effect of the piezoelectric patch which is used as a sensor or actuator in rotating flexible structures such as a helicopter blade, the free vibrations of the rotating rectangular sheet with and without the piezoelectric patch have been presented. First-order shear deformation theory is considered for plate displacement and piezoelectric field. Considering the effect of Coriolis acceleration, centrifugal acceleration and centrifugal in-plane forces, the equations of motion are derived from Hamilton's principle and the electromechanical couple equation is obtained from Maxwell's equation. For piezoelectric, two electrical conditions, open circuit and closed circuit, which are used in sensors and actuators, respectively, have been considered. The equations are discretized with the help of the numerical method of generalized differential squares and the matrices of inertia mass, eccentricity, Coriolis and stiffness matrix are obtained. Natural frequency values for beam and rotating plate have been compared in Abaqus software. Also, the values obtained from the numerical solution in MATLAB have been verified with articles and ABAQUS, which have high accuracy. The effect of parameters such as hub radius, rotation speed, sheet thickness, aspect ratio, piezoelectric patch thickness and applied voltage on the natural frequency of the system has also been investigated.

The purpose of this article is to investigate the effect of corporate governance system monitoring tools on the financial risk of companies listed on the Tehran Stock Exchange. The statistical sample of the study included 127 companies during the period 2011 to 2018. In this study, three variables of credit risk, illiquidity risk and market risk were used as financial risk and the variables of ownership concentration, institutional ownership, board independence and board size were used as monitoring tools of the corporate governance system. Data were analyzed using unit root tests, kao and generalized method of moments using Eviews software. The results showed that institutional ownership has a significant effect on financial risks and reduces credit risk and illiquidity risk while increases market risk. The results also showed that the concentration of ownership, independency and size of the board had no significant effect on financial risks.Keywords: Credit Risk and Illiquidity Risk, Market Risk, Corporate Governance

One of the firms’ tools to provide a low-risk image is adopting a persistent dividend policy. However, it should be noted that due to financial constraints, many firms are unable to implement this policy in the long run. This research investigates the role of earnings quality in adopting a persistent dividend policy in 148 firms listed in Tehran Stock Exchange (TSE) (includes 1628 observations) during 2007-2017. To measure earnings quality, I use five proxies and to investigate their role in adopting a persistent dividend policy, I employ partial adjustment model and dividends adjustment speed concept. To estimate the models, I apply the Generalized Method of Moments (GMM) with system estimator. The research results show that compared with other firms, firms with lower total accruals, lower discretionary accruals, higher accruals quality, smoother earnings and higher overall earnings quality, are more able to conduct a persistent dividends policy. The research results using differenced-GMM estimator confirm the research primary results. These findings are consistent with the predictions of the signaling theory.

Inflation constitutes a significant economic challenge for both citizens and policymakers. A crucial step towards mitigating inflationary pressures and enhancing purchasing power lies in identifying the underlying causes and mechanisms. This study investigates the impact of various factors on inflation dynamics in the Iranian economy, including adaptive and rational expectations, liquidity growth, demand shocks, exchange rate shocks, and government budget deficits. By examining these factors within the framework of established inflation theories, the study aims to inform more effective inflation control and management policies. Employing the Generalized Method of Moments (GMM) and utilizing time series data spanning 1973-2022, the study finds that exchange rate shocks, liquidity growth, and government budget deficits exert the most significant influence on inflation rates in the Iranian economy. Based on these findings, policy recommendations include: reforming foreign exchange policies, adjusting the exchange rate system, controlling liquidity growth, restructuring government finances, and implementing appropriate contractionary monetary and fiscal policies.

governments worldwide are actively optimizing budget efficiency. This research aims to examine the relationship between government budget deficits and economic growth, emphasizing developed and developing countries, particularly the D8 group, during the period from 2010 to 2021, using the System Generalized Method of Moments (SYS-GMM). The results show that in developed and developing countries, especially the D8 group, the negative coefficient of the budget deficit on economic growth can be attributed to concerns such as the effect of congestion, high interest rates, or a decrease in trust in the economy due to financial imbalances and support for the neoclassical approach. In addition, there is an almost one-to-one positive effect between past economic growth and the current level of economic growth. However, this research helps to understand the sustainable impact of budget deficits on current economic conditions in developed and developing countries. Regarding the findings, policymakers should consider adopting contraptions that promote sustainable economic growth while exercising caution in budget deficit management.

Today, the economy and sports industry are concerned as one of the most important economic sectors in all countries, especially developing countries. Sporting goods exports has always been one of the topics discussed economic decision-makers in the context of sports economy. Considering the importance of this sector of the economy sports, this study aimed to investigate convergence of exported goods group during 1992-2012 sports industry in Iran. The research method for the price pair is econometric generalized method of moments by using the Beta and Sigma convergence method in order to investigate the convergence of the grouping. Grouping goods including clothing, shoes, balls and sports equipment. The results showed that there is beta convergence in the sport of exported goods, the rate of convergence in this factor 0. 674 is statistically significant and indicates that the speed of convergence. Also, Sigma convergence test results approved the existence of convergence and reducing the deviations groups are through time. This factor is also statistically significant. Considering the results of the beta and sigma convergence can confirm the existence of convergence in exporting sporting goods group acknowledged Iran during the period studied.

Management earnings forecast is one of the most important information resources in capital markets. The literature suggests managerial overconfidence is an effecting factors on the earnings forecasts’ accuracy. Because of users' relying to forecasted information, examination of the bias's effects on forecasts' accuracy is important. By using a new managerial overconfidence assessment model and Generalized Method of Moments (GMM) regression analysis, the paper examines this managerial bias’ s effect on management earnings forecasts’ error in the firms that have listed at Tehran Securities Exchange (TSE) during the period from year 2007 to year 2016. The results show Chief Executive Officers’ overconfidence has a significant positive effect on earnings forecasts’ error, how overconfident Chief Executive Officers overestimate earnings forecasted above than actual earnings. This finding is consistent with recent researches’ ones and suggests information's users should be aware of Chief Executive Officers' overconfidence's negative effects on reliability of managerial forecasted information.