According to the news, the number of car producers in Casio Country is increasing rapidly. The newspaper reports that "Casio has more car brands now than the United States. But while car sales have climbed 42 percent in the first three quarters of this year, automakers have increased their output even faster, causing fierce competition and a slow erosion in prices." At the same time, Casio consumers' incomes have risen. Assume that cars are a normal good.

a) Use a diagram of the supply and demand curves for cars in Casio to explain what has happened in the Casio car market.

b) Below is a diagram of luxury car market in Casio. As a result of fast growing in the sales of car, Casio began to levy a tax on sales of luxury cars. For simplicity, assume that the tax is an excise tax of $6,000 per car and is paid by the supplier. Under the tax, what is the price paid by consumers? What is the price received by producers? How much tax is paid by the consumers and producers? What is the government tax revenue from the excise tax?