Chapter Five
When demand is unit elastic, price elasticity of demand equals
1, and total revenue does not change when price changes
If the price elasticity of demand for a good is 2.0, then a 10 percent increase in price results in a
20 percent decrease in the quantity demanded
Determinants of the Price Elasticity of Demand
Availability of close substitutes necessities versus luxuries definiton of the market time horizon
If the demand is inelastic, then an increase in price causes
an increase in total revenue
When demand is elastic, a decrease in price will cause
an increase in total revenue
When demand is inelastic, an increase in price will cause
an increase in total revenue
A good will have a more inelastic demand, the
broader the definition of the market
Demand is said to be price elastic if
buyers respond substantially to changes in the price of the good
Demand is said to have unit elasticity if the price elasticity of demand is
equal to one
Demand is elastic if the price elasticity of demand is
greater than one
The flatter the demand curve that passes through a given point, the
greater the price elasticity of demand
If a increase in income results in a decrease in the quantity demanded of a good, then for that good, the
income elasticity of demand is negative
Demand is inelastic if the price elasticity of demand is
less than one
Goods with many close substitutes tend to have
more elastic demands
If two goods are complements, their cross-price elasticity will be
negative
Economists compute the price elasticity of demand as the
percentage change in quantity demanded divided by the percent change in price
IF the quantity supplied is the same regardless of price, then supply is
perfectly inelastic
If two goods are substitutes, their cross-price elasticity will be
positive
Assume that a 4 percent increase in income results in a 2 percent increase in the quantity demanded of a good. The income elasticity of a demand for the good is
positive, and the good is a normal good
When demand is elastic (a price elasticity greater than 1)
price and total revenue move in opposite directions
When demand is inelastic (a price elasticity less than 1)
price and total revenue move in the same direction
The price elasticity of demand measures how much
quantity demanded responds to a change in price
Suppose that corn farmers want to increase their total revenue. Knowing that the demand for corn in inelastic, corn farmers should
reduce the number of acre on which they plant corn
If the quantity supplied responds only slightly to changes in price, then
supply i said to be inelastic
For a good that is a luxury, demand
tends to be elastic
For a good that is a necessity, demand
tends to be inelastic
At points with a low price and high quantity,
the demand curve is inelastic
Income elasticity of demand measures how
the quantity demanded changes as consumer income changes
Demand is said to be inelastic if
the quantity demanded changes only slightly when the price of the good changes
Cross-price elasticity of demand measures how
the quantity demanded of one good changes in response to a change in the price of another good
A key determinant of the price elasticity of supply is the
time horizon
If demand is unit elastic (a price elasticity exactly equal to 1)
total revenue remains constant when the price changes
When demand is perfectly inelastic, the demand curve will be
vertical, because buyers purchase the same amount as before whenever the price rises or falls