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1、SOLUTIONS TO TEXT PROBLEMS:Quick Quizzes1.The price elasticity of demand is a measure of how much the quantity demanded of a good responds to a change in the price of that good, computed as the percentage change in quantity demanded divided by the percentage change in price.The relationship between
2、total revenue and the price elasticity of demand is: (1) when demand is inelastic (a price elasticity less than 1), a price increase raises total revenue, and a price decrease reduces total revenue; (2) when demand is elastic (a price elasticity greater than 1), a price increase reduces total revenu
3、e, and a price decrease raises total revenue; and (3) when demand is unit elastic (a price elasticity equal to 1), a change in price does not affect total revenue.2.The price elasticity of supply is a measure of how much the quantity supplied of a good responds to a change in the price of that good,
4、 computed as the percentage change in quantity supplied divided by the percentage change in price.The price elasticity of supply might be different in the long run than in the short run because over short periods of time, firms cannot easily change the size of their factories to make more or less of
5、 a good. Thus, in the short run, the quantity supplied is not very responsive to the price. However, over longer periods, firms can build new factories, expand existing factories, or close old ones, or they can enter or exit a market. So, in the long run, the quantity supplied can respond substantia
6、lly to the price. 3.A drought that destroys half of all farm crops could be good for farmers (at least those unaffected by the drought) if the demand for the crops is inelastic. The shift to the left of the supply curve leads to a price increase that raises total revenue because the price elasticity
7、 is less than one.Even though a drought could be good for farmers, they would not destroy their crops in the absence of a drought because no one farmer would have an incentive to destroy his crops, since he takes the market price as given. Only if all farmers destroyed their crops together, for exam
8、ple through a government program, would this plan work to make farmers better off.Questions for Review1.The price elasticity of demand measures how much the quantity demanded responds to a change in price. The income elasticity of demand measures how much the quantity demanded responds to changes in
9、 consumer income.2.The determinants of the price elasticity of demand include how available close substitutes are, whether the good is a necessity or a luxury, how broadly defined the market is, and the time horizon. Luxury goods have greater price elasticities than necessities, goods with close sub
10、stitutes have greater elasticities, goods in more narrowly defined markets have greater elasticities, and the elasticity of demand is higher the longer the time horizon.3.An elasticity greater than one means that demand is elastic. When the elasticity is greater than one, the percentage change in qu
11、antity demanded exceeds the percentage change in price. When the elasticity equals zero, demand is perfectly inelastic. There is no change in quantity demanded when there is a change in price.4.Figure 1 presents a supply-and-demand diagram, showing equilibrium price, equilibrium quantity, and the to
12、tal revenue received by producers. Total revenue equals the equilibrium price times the equilibrium quantity, which is the area of the rectangle shown in the figure.Figure 15.If demand is elastic, an increase in price reduces total revenue. With elastic demand, the quantity demanded falls by a great
13、er percentage than the percentage increase in price. As a result, total revenue declines.6.A good with an income elasticity less than zero is called an inferior good because as income rises, the quantity demanded declines.7.The price elasticity of supply is calculated as the percentage change in qua
14、ntity supplied divided by the percentage change in price. It measures how much the quantity supplied responds to changes in the price. 8.The price elasticity of supply of Picasso paintings is zero, since no matter how high price rises, no more can ever be produced.9.The price elasticity of supply is
15、 usually larger in the long run than it is in the short run. Over short periods of time, firms cannot easily change the size of their factories to make more or less of a good, so the quantity supplied is not very responsive to price. Over longer periods, firms can build new factories or close old on
16、es, so the quantity supplied is more responsive to price.10.OPEC was unable to maintain a high price through the 1980s because the elasticity of supply and demand was more elastic in the long run. When the price of oil rose, producers of oil outside of OPEC increased oil exploration and built new extraction capacity. Consumers responded with greater conservation efforts. As
