جستجوی مقالات مرتبط با کلیدواژه "رابطه غیرخطی" در نشریات گروه "اقتصاد"

The relationship between credit and economic growth is one of the issues discussed by economists and recent studies have shown that the relationship between credit and economic growth can be nonlinear. The aim of this study was to investigate the nonlinear Granger causality between the credit variable (which is the most important criterion for financial development) and the economic growth variable. For this purpose, Granger causality in the form of MSVAR model and seasonal data in the period 1383: 1 to 1398: 4 have been used. The results show a nonlinear relationship between economic growth and validity and MSVAR model has better explanatory power than its linear competitor (VAR model). According to this study, in regime one (which corresponds to periods of positive economic growth and high credit growth), causality exists only in terms of economic growth to credit, and in regime two (which corresponds to periods of economic growth and low credit growth) Causality is from credit to economic growth. In other words, in periods of prosperity, an increase in credit cannot significantly boost economic growth, and due to credit constraints in bad economic conditions, an increase in credit can affect economic growth

Empirical literature on the relationship between military spending and unemployment presents heterogeneous and different findings. A group of studies show that military spending can help reduce unemployment, while another group has concluded that military spending exacerbates unemployment. A group also shows that there is no relationship between military spending and unemployment. According to this, Lee (2021) using a theoretical model including supply-side effect, demand-side effect and security effect caused by military spending in the form of a random endogenous model shows that the relationship between military burden and unemployment (employment) is non-linear and U-shaped (U reverse). In this regard, the main goal of this article is the empirical test of this hypothesis in 171 countries of the world during the years 2001-2020. For this purpose, the effect of military burden on the unemployment rate has been modeled by using the theoretical literature and applying the threshold panel method. The results show that the effect of military burden on unemployment is non-linear and in the form of a U-shaped relationship. The threshold level value of military spending is also estimated at 1.61% of GDP. In other words, before the threshold level, the military burden had a negative and significant effect on the unemployment rate; But after crossing this threshold level, the military burden has a positive and significant effect on the unemployment rate, which confirms the hypothesis of Lee (2021).

Based on theoretical foundations and empirical studies in the field of the relationship between natural resources and internal conflict, 4 states can be imagined: a. Positive relationship between natural resources abundance and internal conflict (hypothesis of political resources curse) b. positive relationship between natural resources scarcity and internal conflict (hypothesis of political resources endowment) c. Non-linear relationship between natural resources and internal conflict (combination of state A and B) d. Absence of relationship. Based on this, the main purpose of this article is to investigate the relationship between natural resources types and internal conflict risk in the MENAP region countries during the period of 2000-2019 using the System Generalized Method of Moments (SGMM). For this purpose, the index of the percentage share of total natural resource rent from GDP and eight separate indicators including: the percentage share of oil, natural gas, coal, forest and mining rent from GDP, the percentage share of fuel export and the export of ore and metals from the export of goods and the percentage share of arable land in the total area have been used. The results show that there is a U-shaped relationship between the total rent of natural resources and the internal conflict risk; In other words, countries with a shortage of natural resources as well as countries with an abundance of natural resources have a higher internal conflict risk than other countries. This U-shaped relationship is also confirmed for oil rent and fuel export. Also, coal and forest rent have a meaningless effect and arable land has an inverted U effect on the internal conflict risk in the studied countries. The evaluation of the marginal effect of the total rent of natural resources on the internal conflict risk shows that its value varies from -0.08 to 0.1. According to the other results, per capita income and democracy have a negative and significant effect, and population and religious and racial tensions have a positive and significant effect on the internal conflict risk.

Corruption and economic security are among the most important issues in Iran's economy today. In the economic literature, economic corruption can also facilitate bureaucracy and business. It acts as an oil between the hard gears of an economical machine that can also reduce performance and economic security by increasing transaction costs and risk. Therefore, in this study, the analysis of the nonlinear relationship between economic corruption and economic security in Iran, during the period of 1357 - 1397, thresholds are performed using the regression method. This research is applied in terms of purpose and descriptive correlation in terms of type and method of research. The results of estimating the research model show that the threshold for corruption is 0.45. Hansen's linear test results with the Bootstrap method also confirm the threshold significance. The implication of this threshold is that in a government with less than 0.45 corruption, increasing the size of corruption has a significant and negative effect on economic security. But in a regime with greater corruption, corruption has a positive effect on economic security. In other words, the non-linear relationship between economic corruption and economic security in the country is confirmed and indicates a long-term relationship between corruption control and economic security in Iran.

The purpose of this paper is to introduce criteria for investors to improve their company's profitability and performance. In this regard, this study investigates the nonlinear relation hypothesis among firm size and stock returns, with respect to the firms listed on Tehran Stock Exchange during the five-year period between 2008 and 2016. Due to the importance of the relationship between risk and return, asset pricing models were always explained. Capital asset pricing model was introduced as the starting point for asset pricing models. Subsequently, other asset pricing models, including Fama model, French model, arbitrage model, etc., as the most important models were developed by adding and modifying variables. In most of the models, variable size enterprise is one of the most important determinants of returns. On the other hand, with the development of studies and changing circumstances, some factors lose their explanatory power. For example, the result of a study done by Hung, Azad & Fang(2014) showed that most of factors which were tested lost power explaining. Also, some research results show that the form of relationship between risk and returns is possible to change in some conditions. For example, the results of a study done by Apergis & Payne (2014) showed that there is a nonlinear relationship between enterprise size and returns. In this study, two models with two different statistical methods were used to test hypothesis of nonlinear relationship between enterprise size and returns. The first model uses a panel nonlinear cointegration method to confirm or reject hypothesis, and investigates positive and negative effects of enterprise size over returns. Using a panel co-integration method, the second model tests nonlinear relationship, i.e. the inverted-U cure hypothesis, between firm size and stock returns. The results of analysis of data in the first model based on a panel nonlinear cointegration model, provide evidence of asymmetric effects and nonlinear relationship between stock returns and firm size. On the other hand, the results of analysis of data in the second model based on panel data also confirm that there is a nonlinear relationship, i.e., inverted U curve, between firm size and stock returns at the company level.
According to the results mentioned, investors, shareholders and Capital market analysts are recommended to consider firm size as the most important factor to explain returns and pay attention to this issue that there is a nonlinear relationship between firm size and stock returns.

Governmental debts mean income reduction and increase of government expenditures with impression on household disposable income that influence on their consumption. This impact, in some cases has expansion positive effects and in some other cases, reduces consumption, investment and economic growth and other values. The main aim of this paper is to study the linear and non-linear relations between consumption of private sector and government debts in Iran. For this purpose, the period between 1358-1395 years was considered and after confirmation of non-linear relation, government debt threshold was achieved by Smooth Transition Regression method . Results show that in the considered time period, the average government debt to GDP was around 60%, but threshold was estimated 46%. In other words, passing threshold causes by increasing government debts and probability of government inability to debts repayment, consumption of private sector will be reduced indirectly. So Policy makers in Iran cannot leverage government debt as a positive expansion in Iran's economy.

Inflation affects budget deficit on both revenue and expenditur sides. Understanding the effect of inflation on the government's budget deficit could be some what appropriate conditions to control inflation and reduce the deficit. Using of seasonal data over the period of 1991:2-2015:1, this study investigates the effectof inflation on iran's budget deficit. To do so, the research model has been estimated in different percentiles using a quantile regression. The results indicate that, as inflation rises, the budget deficitis decreased. On the other hand Patinkins effect dominants of Tanzis effect. In fact, the result shows that although inflationreduces the real expense and revenues of government, but it is reducing government expense more than government revenues and as a result increasing inflation caused toreducing ofthe budget deficit. Due to the different levels of inflation in iran, there is a non-linear relationship between inflation and budget deficits, because as the results of the research show, in primary percentiles, the effect of inflation on the deficit is more than on intermediate percentiles.with the implementation of resampling (bootstrap) as the results estimation quantile regression of the model was confirmed.

This study investigates the impacts on government spending and its financing resources including tax revenues، oil revenues and government debts on GDP in Iran during 1350 to 1387 period. For this regards، Smooth Transition Regression (STR) model has been employed. The results show that، there is a significant nonlinear relationship among government spending and its financing resources and GDP with respect to inflation as a transition variable. The STR estimation results show that، threshold value of inflation is 14. 8 percent and smoothing parameter is equal to 10. Based on the results، in first regime where inflation is lower than threshold value، government spending، tax revenues، oil revenues، government debts and inflation have positive، negative، negative، positive and positive effects on GDP، respectively. In second regime، where inflation is higher than threshold value، the maintained variables have negative، positive، positive negative and negative effects on GDP. All the estimated coefficients of model are significant. The results of robustness check tests also indicate on enough validity of STR model in order to fit the maintained relationship. These results emphasis on inflation control and necessarily of reduction the government dependence on oil revenues and banking debts.

In this paper an attempt is made to investigate the nonlinear relationship between real interest rate and private investment in certain developing countries، during the period (1970-2007)، by using the dynamic threshold panel model. Results indicate that the real interest rates have positive effect on investment before the threshold point i. e. about 5-6 percent، but by passing over the estimated threshold point، real interest rates have negative effect on private investment. Thus، if real interest rates increase beyond threshold point، their impact on investment will be perse negative.