energy economics

i) Using a demand/supply diagram of the world oil market, explain some possible causes of the recent decline in oil prices.

ii) The demand and supply curves for gasoline are given by the following equations where P is the price per gallon and Q is the quantity of gasoline in gallons: Market Demand: Q = 10,000 - 1000P Market Supply: Q = 4000 + 2000P Find the equilibrium price and quantity of gasoline in this market.

iii) Suppose that the government decides that less gasoline should be consumed due to concerns about climate change. The government decides to impose a tax so that the total consumption of gasoline falls by 3000 gallons from its equilibrium quantity. The government has asked you to advise them as to the size of the tax that will be necessary to achieve this goal. Assume that the only thing that changes in this market is the tax. What is the size of the tax?

iiii) Calculate the tax revenue and dead weight loss that will result from the tax that you have calculated. Show the tax revenue and the deadweight loss in the diagram that you have drawn in part (1) of this question.