Self-Check Questions

changes by an infinite amount in response to any change in price at all. Zero elasticity refers to the extreme case in which a percentage change in price, no matter how large, results in zero change in quantity. Constant unitary elasticity in either a supply or demand curve refers to a situation where a price change of one percent results in a quantity change of one percent.

5.3 Elasticity and Pricing

In the market for goods and services, quantity supplied and quantity demanded are often relatively slow to react to changes in price in the short run, but react more substantially in the long run. As a result, demand and supply often (but not always) tend to be relatively inelastic in the short run and relatively elastic in the long run. A tax incidence depends on the relative price elasticity of supply and demand. When supply is more elastic than demand, buyers bear most of the tax burden, and when demand is more elastic than supply, producers bear most of the cost of the tax. Tax revenue is larger the more inelastic the demand and supply are.

5.4 Elasticity in Areas Other Than Price

Elasticity is a general term, that reflects responsiveness. It refers to the change of one variable divided by the percentage change of a related variable that we can apply to many economic connections. For instance, the income elasticity of demand is the percentage change in quantity demanded divided by the percentage change in income. The cross-price elasticity of demand is the percentage change in the quantity demanded of a good divided by the percentage change in the price of another good. Elasticity applies in labor markets and financial capital markets just as it does in markets for goods and services. The wage elasticity of labor supply is the percentage change in the quantity of hours supplied divided by the percentage change in the wage. The elasticity of savings with respect to interest rates is the percentage change in the quantity of savings divided by the percentage change in interest rates.

Self-Check Questions

1 . From the data in Table 5.5 about demand for smart phones, calculate the price elasticity of demand from: point B to point C, point D to point E, and point G to point H. Classify the elasticity at each point as elastic, inelastic, or unit elastic. Points P Q A 60 3,000 B 70 2,800 C 80 2,600 D 90 2,400 E 100 2,200 F 110 2,000 G 120 1,800 H 130 1,600 TABLE 5.5 2 . From the data in Table 5.6 about supply of alarm clocks, calculate the price elasticity of supply from: point J to point K, point L to point M, and point N to point P. Classify the elasticity at each point as elastic, inelastic, or unit elastic. Point Price Quantity Supplied J $8 50 K $9 70 L $10 80 M $11 88 N $12 95 P $13 100 TABLE 5.6 3 . Why is the demand curve with constant unitary elasticity concave? 4 . Why is the supply curve with constant unitary elasticity a straight line? 5 . The federal government decides to require that automobile manufacturers install new anti-pollution equipment that costs $2,000 per car. Under what conditions can carmakers pass almost all of this cost along to car buyers? Under what conditions can carmakers pass very little of this cost along to car buyers? 6 . Suppose you are in charge of sales at a pharmaceutical company, and your firm has a new drug that causes bald men to grow hair. Assume that the company wants to earn as much revenue as possible from this drug. If the elasticity of demand for your company’s product at the current price is 1.4, would you advise the company to raise the price, lower the price, or to keep the price the same? What if the elasticity were 0.6? What if it were 1? Explain your answer. 7 . What would the gasoline price elasticity of supply mean to UPS or FedEx? 8 . The average annual income rises from $25,000 to $38,000, and the quantity of bread consumed in a year by the average person falls from 30 loaves to 22 loaves. What is the income elasticity of bread consumption? Is bread a normal or an inferior good? 9 . Suppose the cross-price elasticity of apples with respect to the price of oranges is 0.4, and the price of oranges falls by 3%. What will happen to the demand for apples?

Review Questions

10 . What is the formula for calculating elasticity? 11 . What is the price elasticity of demand? Can you explain it in your own words? 12 . What is the price elasticity of supply? Can you explain it in your own words? 13 . Describe the general appearance of a demand or a supply curve with zero elasticity. 14 . Describe the general appearance of a demand or a supply curve with infinite elasticity. 15 . If demand is elastic, will shifts in supply have a larger effect on equilibrium quantity or on price? 16 . If demand is inelastic, will shifts in supply have a larger effect on equilibrium price or on quantity? 17 . If supply is elastic, will shifts in demand have a larger effect on equilibrium quantity or on price? 18 . If supply is inelastic, will shifts in demand have a larger effect on equilibrium price or on quantity?