بدهی های خارجی

One of the economic problems in the developing countries is the debt problem. External debt occurs in the developing countries due to the elimination of the restrictions on the savings gap, the foreign exchange gap, and the fiscal gap in order to form the capital to accelerate the economic growth (Karakoy et al., 2012, p. 491). In contrast, borrowing and rising the external debt could be little in the economic growth of these countries due to theadverse economic effects such as debt overhang problems, crowding out effect, and uncertainty (Karakoy et al., 2012, p. 491). In general, there are three groups of theories regarding how to influence the external debt for the economic growth. The first group of theories relates reasonable debt levels to positive effects on growth; the second relates the high accumulated debt levels to the negative effects on growth (low growth), and the third combines those two effects while arguing that the impact of debt on growth is nonlinear by nature (Oleksandr, 2003). In this regard, the main purpose of this paper is to investigate the non-linear impact of the external debt on the economic growth in 8 Developing (8D) countries group including Indonesia, Iran, Bangladesh, Pakistan, Turkey, Malaysia, Egypt, and Nigeria.
Theoretical frame work
For the purpose of this paper, the researcher adopted the debt overhang theory. The debt overhang theory is based on the premise that if the debt will exceed the country's repayment ability with some probability in the future, the expected debt service is likely to be an increasing function of the country's output level. Thus, some of the returns from investments in the domestic economy are effectively taxed away by the existing foreign creditors while the domestic and new foreign investors are discouraged (Claessens, 1996). Under such circumstances, the debtor country shares only partially in any increase in output and exports because a fraction of that increase will be used to service the external debt. The theory implies that the debt reduction will lead to the increased investment and repayment capacity, thus, the portion of the outstanding debt becomes more likely to be repaid. When this effect is strong, the debtor is said to be on the wrong side of the debt Laffer curve. In this case, the debt Laffer curve is referred to the relationship between the amount of debt repaid and the size of the debt. However, the idea of the debt Laffer curve also implies that there is a limit at which the debt accumulation stimulates growth (Elbadawi et al., 1996). In reference to the debt Laffer curve, Lensink and White (1999) argue that there is a threshold at which more debt is detrimental to grow.
The liquidity constraint is captured as a crowding out effect, by which the requirement for the service debt reduces funds available for the investment and growth. A reduction in the current debt service should, therefore, lead to an increase in the current investment for any given level of future indebtedness (Cohen, 1993). Other channels which can affect the need to service a large amount of external obligations for the higher economic performance include the lack of access to the international financial markets and the stock debt on the general level of uncertainty in the economy (Claessens, 1996). However, debt has to be repaid. Funds borrowed will simply postpone the taxation. Hence, the purpose for which the funds are gained and their relative returns becomes crucial. If the government invests on the infrastructure such investments are capable of leading to the faster growth and the socio-economic development (Mowlaei & Golkhandan, 2014).
In order to determine the reaction of the economic growth to the external debt and other traditional sources of growth, the following logarithmic production function in a Panel Smooth Transition Regression (PSTR) model is used. In this model, countries are denoted by the subscript i and the subscript t denotes the time period (1991-2013). Other variables are defined as follows: GDP: Gross domestic product per capita; ED: The ratio of the total external debt to the gross domestic product; INV: The ratio of the fixed gross capital formation to the gross domestic product; EDU: The ratio of the education expenditure to gross the domestic product; GOV: The ratio of the government final consumption expenditure to the gross domestic product; OPEN: The degree of the economic openness index by the ratio of the sum of exports and imports to the gross domestic product; POP: Population; INF: Inflation rate; r: The number of transfer functions; g: Transfer functions; q: Transmission (threshold) variable; : Slope parameter; c: The vector of threshold parameters.
The linearity test results indicated that there is a strong nonlinear relationship among variables under consideration. Moreover, considering one transition function with one threshold parameter, that represents a two-regime model, is sufficient to specification of nonlinear relationship among variables. The results indicated that the threshold value is 34.12 percent and the estimated slope parameter is 1.83. In order to provide the clearer evidence of the obtained results, two extent regimes were investigated: First regime : Second regime : Based on the above results, in the first regime, the external debt has a little negative impact on the economic growth. Beyond the threshold level, in the second regime, this negative impact increases.
Conclusions & Suggestions: This paper investigates the threshold effects of the external debt on the economic growth in eight developing countries from 1991 to 2013 using Panel Smooth Transition Regression (PSTR) model as one of the most prominent regime-switching models. The linearity test results indicated a strong nonlinear relationship among the variables under consideration. Moreover, considering one transition function with one threshold parameter, that represents a two-regime model, is sufficient to specification of nonlinear relationship among variables. This negative impact increases if it is beyond the threshold value in the second regime. Therefore, not only the external debt has not played an important role in the acceleration of the economic growth in the eight developing countries; but also, its increase is the barrier to economic growth in these countries. The results have important implications for the policymakers of the eight developing countries. It is a major challenge for the governments to formulate a prudent debt management policy to control and maintain the level of indebtedness of their countries at a manageable level before it becomes too late and the country becomes involved in a debt overhang situation or, to a lesser extent, is in default.

In 1980s many countries to finance their spending,used internal resources, especially bank credits. Government spending financing by non-bank was used in low level, because capital markets had not formed or were not strong in most countries and also financial assets were not available. After World War II and the effectiveness of US aid to Europe, several articles were written about the impact foreign aid. Some theories believe that foreign aid such as loans, block grants can provide economic growth, but increased lending to developing countries in the 1970s and followed debt crisis in 1982 quesioned the impact of external debt on economic growth.
According to International Debt Statistics published by the International Bank for Reconstruction and Development in 2015, total external debt of developing countries is about 5506 billion dollars, which Iran's share is 7647 million dollars . According to the report, China is the largest debtor among developing countries so that the external debt of this country is about 874 billion dollars. China's external debt in 2013 has increased more than 6 times than 2000.
One of the main challenges which most developing countries facing, is ways of financing the budget deficit and its impact on economic growth in these countries. Choosing financing instruments, especially liabilities are important for rapid economic development and being aware of the impact of these policies on macroeconomic variables is very important. How to finance the budget deficit is the key to financial sector reform. The purpose of this study was to estimate the effects of external debt, budget deficits and exports on economic growth in developing countries. For this purpose,panel data for the period 2003-2013 and GMM estimation method have been used.
Theoretical frame work: In general, there are three views to the use of external resources. The first view is theories that consider external sources important for growth and economic development. This view suggests that developing countries are known poor economies in terms of low savings and capital and low investment. In fact, developing countries because of low saving rate can not finance expenditures related to depreciation and replacement of capital goods. As a result, for such countries, external resources are critical to reach ideal economic growth. The second view includes theories that foreign aid is not essential for growth and development. Bauer and Yamey (1989) believe: "For developing countries, foreign aid is not necessary or sufficient for liberation from poverty, but it is possible to grow and develop without foreign aid if necessary conditions are provided and economic and social projects are done. Also if these conditions are not provide, economic development is not possible, even with the presence of foreign aid and foreign resources will be wasted ".The third view includes those views which know foreign unsufficient condition for economic growth, but believe that proper management of external debt, provides the possibility economic growth and development. The management includes allocated loans to the production of export goods and prevents the losses of received aid and so on (Gharabaghi, 1993).
Theoretical models about growth and foreign aid includes two gap patterns, Griffin theory, model three gaps and overhang hypothesis. Before the two-gap model, growth patterns often proposed based on the savings gap, But Chenery & Bruno (1962) showed savings gap is not the only limiting factor. Griffin (1970) by statistical analysis revealed that only 25 percent of the external debt is allocated to growth activities. In the other words , 75% foreign loans taken for consumption expenditures. One of the main criticisms about the two gap pattern was that received foreign loans apart from the savings and exchange gap may be due fiscal gap and budget deficit reduction. So third limitation was introduced for the growth, was the limitation of public financing gap. Bacha (1990) suggests that the economy could fill three gaps savings, foreign exchange and Budget deficit by external sources and enter the growth path. One of the main channels which external debt impact on economic growth through it, is Debt overhang (Krugman, 1988; Sachs, 1989). Large debt burden is an obstacle to investment, because investors expect return on investment reduce due to foreign creditors.
In this study, the model Jayaraman & Liu (2009) is used: That, RGDP represents real production as a numerical index, ED real external debt (GDP%), EXP real exports of goods and services (GDP%), BD real budget deficit (GDP%) and ε random error term. consumer price index (CPI) is used for real nominal variables. In this study the generalized method of moment's (GMM) is used to estimate the model. GMM estimator is developed by Arellano & Bond (1991) and Arellano & Bover (1995). Gmm estimation method used the two sets of cross-sectional data and time series data. The method can solve the endogeneity problems between explanatory variables. In this method, dependent variable is added to the equation with a lag as an explanatory variable (Abrishami et al., 2006). To solve the correlation between the lagged dependent variable and the error term, lag variables are used as instruments in GMM. Also consistent estimators of GMM, depends on the validity of the instruments used. To test this, the use of statistics proposed by Arellano & Bond (1991) and Arellano & Bover (1995), which is called Sargan test and validate the instruments used to measure (Yavari, et al.2010).
Based on the results, the total external debt and budget deficits have negative impact on economic growth so that one percent increase in the total external debt reduced economic growth by 0.7%. Also increase one percent in the budget deficit reduced economic growth 0.035%. While exports have a positive impact on economic growth so that one percent increases in exports increase economic growth 0.21%.
In the second model, short-term external debt has positive effects, but long-term external debt has a negative impact on economic growth. So that a one percent increase in short-term external debt, increases economic growth 0.032% and with an increase in long-term external debt, reduces economic growth of 0.12%. Budget deficit has a negative impact on economic growth, while exports had a positive effect, as a one percent increase in budget deficit, reduced economic growth 0.005% and a one percent increase in exports increased 0.24%.
Also estimated results for the two groups of countries: countries with upper-middle per capita income and lower-middle and lower-income countries , have been reflected. According to estimates, total external debt in both countries has a negative impact. While short-term external debt has positive impact on economic growth, but long-term external debt has negative impact on economic growth. Budget deficit and exports in countries with low and lower-middle income have positive impact on economic growth, while the upper-middle income countries have negative effects.
Conclusions & Suggestions: The results show that, long-term external debt and budget deficit have significant negative effects on economic growth in developing countries. However, exports and short-term external debt have positive impact on economic growth in developing countries. While the external debt is divided into 2 groups: short-term and long-term external debt, the results show that short-term external debt have positive impact on economic growth but long -term external debt have negative impact on economic growth. However, the budget deficit is a negative impact on economic growth but exports have positive impact n economic growth. According to the results, measures to reduce long-term external debt should be taken in developing countries and prevent the adoption of long-term debt or long-term debt become short-term debt. Also, due to the positive impact of exports on economic

The budget deficit policy is one of the fiscal policy instruments for eliminating the shortage of government revenues and achieving targeted economic growth in many countries. In recent years, for various economic problems in Iran, governments get some parts of the budget deficit from different sources. Foreign borrowing is one of the sources of deficit financing and the ways of using it may have positive and negative effects on economic growth. In this paper the empirical relationship between budget deficit and economic growth of Iran in the period 1980-2011 is analyzed in long and short run applying Johansen and Juselius co-integration method and vector error correction model (VECM). Results suggest that the impact of external debt on economic growth is negative and significant in the long run and short run. Thus, the optimal foreign borrowing and the other sources of deficit financing should be used for increasing employment and the high efficiency projects and the ability to pay foreign and domestic debts are necessary for achieving the targeted growth.

Nowadays, achieving high growth rate is seen as a major purpose for any economic system. The budget deficit policy in developing countries is considered as an important element in policy-making, and the effect of this variable on economic growth is particularly important. In this paper the empirical relationship between budget deficit and economic growth of Iran in the period 1980-2011 is analyzed in long and short run applying Johansen and Juselius co-integration method and vector error correction model (VECM). Results suggest that the impact of ratio of budget deficit to GDP on economic growth is negative and significant in the long run, and positive and significant in the short run; but in such a way that the negative effects in long-run are much stronger than the positive effects in short run. The results also show that in long-run, external debt has a negative significant effect on economic growth while public sector investment has a positive significant effect. However, in short run these two variables do not demonstrate any significant effect on economic growth.

Concentrating on the international conditions of Iran economy in recent years, exhibits extensive economic sanctions as well as variations in crude oil prices. It shows the effect of unanticipated factors under above condition on official foreign reserves. In order to achieve macroeconomic targets, we study the feasibility of optimal policy for foreign reserves combinations.Using Mean-Variance approach, we try to simulate official foreign reserves in Iranian economy within the period of 1999-2007.The results show that the average share of the U.S Dollar and Pound were more than its optimum share, while the average shares of the Euro and Yen were less than their optimum shares.