جايگاه حمل و نقل و تاثير آن بر ديگر بخش‏هاي اقتصاد كشور:يك تحليل داده-ستانده

Transport Position and Its Effect on the Other Economic Sectors in Iran: An Input-Output Analysis

اين مقاله در پي تعيين موقعيت بخش حمل و نقل در اقتصاد ايران و تاثير آن بر ديگر بخش‏هاي اقتصادي كشور است. براي تعيين ميزان تاثيرگذاري اين بخش در توليدات ديگر بخش‏هاي اقتصادي و مقايسه آن با اين بخش‏ها، از پيوندهاي پيشين كل (خالص و ناخالص) استفاده مي‏گردد. ميزان تحرك آفريني توسعه فعاليت‏هاي حمل و نقل در بخش‏هاي مختلف اقتصادي با استفاده از شاخص ارتباط پسين كل (خالص و ناخالص) اندازه‏گيري مي‏شود. منابع آماري تحقيق از جدول داده- ستانده سال 1380 مركز آمار ايران كه آخرين جدول آماري كشور است تامين مي‏گردد. به دليل اين كه 8/45% از خدمات حمل و نقل به مصرف نهايي مي‏رسد، موقعيت اين بخش، به لحاظ زمينه سازي براي توليدات بخش‏هاي توليدي از متوسط بخش‏هاي اقتصادي اندكي بالاتر و به لحاظ تحرك آفريني در بخش‏هاي توليدي، از متوسط بخش‏هاي اقتصادي اندكي پايين‏تر است. از نظر رتبه بندي، رتبه حمل و نقل در بين 40 بخش توليدي كشور در همه اين شاخص‏ها از 19 تا 22 در نوسان مي‏باشد

This paper investigates the possibility of both linear and nonlinear effects of energy consumption on economic growth in Iran, using data for the period of 1959–2007 based on threshold regression. Some previous studies support the view that energy consumption may promote economic growth. However, the conclusion drawn from this study suggests that such relationship exists only where there is a low level of energy consumption in Iran. The evidence shows that, there are two break points (corresponding with three regimes) in economic growth function. For the low energy consumption regime (where per capita energy consumption is less than 5 barrels) we find that energy consumption has an important positive influence on economic growth with coefficient 0.09, which is not the case with the high or middle regime. In middle regime with per capita energy consumption between 5 and 8 barrels, the marginal effect of energy use on economic growth gets to 0.015. For the regime corresponding to per capita energy consumption above the threshold 8 barrels, the marginal effect of energy use is reduced to about zero. We show that a threshold regression provides a better empirical model rather than the standard linear model and policy-makers should seek to capture economic structures associated with different stages of economic growth.