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The crude oil is both a commodity and a financial asset. As there are many factors affecting the crude oil spot and futures markets, the analysis of the relationship between major factors of these markets is complicated. The main objective of this paper is to investigate the relationship between the price of crude oil in spot and futures market and identify the effect of the crude oil inventory and the interest-adjusted basis risk on these price changes. The monthly data of WTI spot and futures prices, WTI crude oil inventory and interest-adjusted basis risk are from EIA (Energy Information Administration) database. The data period is from January 1986 to December 2010. Due to the unpredictable volatilities and uncertainties in variables, the GARCH error process models are used. Empirical results show that there is a positive, strong and significant relationship between the spot crude oil price changes and futures prices. Additionally, the basis risk changes can affect the spot and futures crude oil prices up to three lags. Also, crude oil inventory changes have a negative effect on the spot crude oil price changes with one lag.

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  Today the quantitative assessment of economic and social impacts of petroleum products supply constraints is one of the main policy issues in Iran. This issue arises from the fact that importing gasoline, gasoil and liquefied petroleum gas (LPG) is restricted by international sanctions. In this paper, we showed that a demand driven Social Accounting Matrix (SAM) is not a suitable tool for answering the above question. So, a modified SAM, known as mixed supply driven SAM is suggested. For this purpose the energy SAM of 2006 is used.

  The overall results reveal that: 1) Petroleum products supply constraints have the most impacts on crude oil and natural gas, retail and wholesale, chemical and agricultural sectors.2) Operating surplus has the most reduction among the other production factors. Results also showed that the fall of urban income as a consequence of supply constraints is more than rural labor either relatively or absolutely.