نا متقارن بودن عكس العمل تقاضا براي نفت نسبت به تغييرات درآمد و قيمت نفت: مقايسه چين و كشورهاي توسعه يافته طي سالهاي 2008-1970

Asymmetric Impact of Changes in Oil Prices and Income on Demand for Oil: China and OECD Countries (1970-2008)

In this paper we are concerned with testing the so called imperfect reversibility of demand for oil response to changes in oil prices and the GDP in China and OECD countries. We examine three important issues: demand asymmetric effect on oil price developments; the asymmetric effects of demand on the developments of GDP; and the different speed of demand adjustment to changes in oil prices and income. Our main conclusion are as follows: (1) China and OECD countries respond much more to increase in oil prices than to the decrease of it; ignoring this asymmetric price response will bias downward the estimated response to income changes; (2) demandʹs responses to GDP per-capita changes in China and OECD countries are not necessarily asymmetric; ignoring this imperfect reversibility of demand response to income changes will bias the estimated response to income changes; (3) the speed of demand adjustment to income changes is faster than the adjustment to oil price developments; ignoring this difference will bias upward the estimated response to income changes. Using proper specified equations for oil demand, the short and long-run response of demand for oil to income growth are figured out 0.67 and 0.72 in China and 0.49 and 0.49 in OECD countries respectively. The short to long-run price elasticity of demand for oil are -0.085 and -0.55 for China and -0.075 and -0.2 for OECD countries respectively. Therefore, income and price elasticity of demand for oil are higher in China compared to OECD countries. Speed of demand adjustment to income and (oil) price changes; on the other hand, are higher in OECD countries than China. We find almost no lag for a response of oil demand to income change in OECD countries while for China the demand adjustment to income changes is estimated 93%. Speeds of demand adjustment to price changes are 0.39 and 0.15 for OECD and China respectively.