答案和详解如下： Q1. Assume that Rajesh Singh’s income increased from $20,000 per year to $30,000 per year, and his demand for “store-brand” bread decreased from 80 loaves to 40 loaves per year. Which of the following most accurately describes Singh’s income elasticity for store-brand bread? A) Income elasticity is -0.60 and store-brand bread is an inferior good. B) Income elasticity is -1.67 and store-brand bread is an inferior good. C) Income elasticity is +1.00 and store-brand bread is a complimentary good. Correct answer is B)
Average income is ($20,000 + $30,000) / 2 = $25,000, so the percentage change in income is ($30,000 – $20,000) / $25,000 = 40.00%. The average quantity of bread demanded is (80 + 40) / 2 = 60 loaves, so the percentage change in the quantity of bread demanded is (40 – 80) / 60 = -66.67%. Income elasticity of store-brand bread is -66.67 / 40 = -1.67. Since Singh’s income elasticity of demand is negative, store-brand bread is an inferior good. Q2. The percent change in demand for a good divided by the percent change in the price of an other good is known as the: A) income elasticity of demand. B) price elasticity of demand. C) cross elasticity of demand. Correct answer is C) Q3. If a 10% income increase caused a group of consumers to increase their purchases of television sets from 95 to 105, the group's income elasticity of demand for television sets would be closest to: A) 1.00. B) 0.10. C) 2.00.
Correct answer is A) Income elasticity is the sensitivity of demand to changes in consumer income. Income elasticity = (percent change in quantity demanded) / (percent change in income) = [(105 − 95) / (100)] / 0.10 = 1 Q4. Price elasticity of demand is most accurately defined as the change in: A) quantity demanded in response to a change in market price. B) market price in response to a change in the quantity demanded. C) quantity demanded in response to a change in income. Correct answer is A)
Q5. George’s Appliance
Center sells big screen televisions. On a representative model, when the price was reduced from $2,450 to $2,275, monthly demand increased from 175 to 211 units. What is the price elasticity of demand? A) -1.69. B) -2.53. C) -2.14. Correct answer is B) Price elasticity of demand = % change in quantity demanded / % change in price % change in quantity = (211 − 175) / [(211 + 175)/2] = 0.187 % change in price = (2,275 − 2,450) / [(2,275 + 2,450)/2] = -0.074 Price elasticity of demand = 0.187 / -0.074 = -2.53 | 
发表于 2008-12-31 09:17
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