Slide 5 Flashcards
what is price elasticity of demand
the elasticity is the responsiveness of the quantity demanded of a good to a change in its price.
all other influences on buying plans remain the same
what is the equation of price elasticity of demand
delta Q / delta P * avg(P) / avg (Q)
or
percentage change in quantity demanded / percentage change in price
is the price elasticity of demand the same as slope?
no it is not the same as slope. slope is
change in quantity demanded / change in price
true or false: the price elasticity of demand can be negative
true, but we only care about magnitude to highlight elasticity, sign does not matter.
it will always be negative because a positive change in price is always a decrease in demand
what does it mean for a good to have perfectly inelastic demand.
what does the graph look like.
give an example of something that would
if the quantity demanded does not change when the price changes
the demand curve would be a vertical line
Examples
- water
- medicine
what does it mean for a good to have unit elastic demand
it means the percentage change in
the quantity equals the percentage change in price
which means that
the price elasticity of demand = 1
what does it mean for a good to have a perfectly elastic demand
what does the graph look like
what can you infer based off how far the demand curve spans
it will be perfectly elastic if there is an infinitely large demand change when the price barely changes
it looks like a horizontal line when graphed. the graph implies that when the price is X there is an infinite demand and if it deviates from X there is no demand
narrow demand curves implies that the market is more elastic. because there is quicker change for less of a price difference. Vice versa logic for larger spans
define elastic and inelastic and how they differ
if the change is quantity is less than the change in price, we have a price elasticity of demand with a value < 1
if the value is less than 1, we have a inelastic demand
if the change is quantity is more than the change in price, we have a price elasticity of demand with a value > 1
if the value is greater than 1, we have a elastic demand
what are the three factors that can influence the elasticity of demand
- the closeness of substitutes
- the proportion of income spent on the good
- the time elapsed since a price change
true or false: the elasticity of a demand changes along a demand curve
true
how does the elasticity change along a linear demand curve
at the top of the demand curve it is elastic because ε > 1
at the midpoint of the curve it is unit elastic because ε = 1
and at the lower half it is inelastic because ε < 1
what is total revenue
the cost of the good * the amount of goods sold
does an increase in price always result in an increase in total revenue?
no
describe what happens to total revenue if we have an elastic, inelastic and unit elastic demand
If demand is elastic, a price cut increases the quantity sold and total revenue increases
If demand is inelastic, a price cut increases the quantity sold and total revenue decreases
If demand is unit elastic, a price cut increases the quantity sold and total revenue stays the same
what is the total revenue test
it is a method of estimating the price elasticity of demand by looking at how total revenue changes with the change in price
if price cuts and TR increases, elastic
if price cuts and TR decreases, inelastic
if price cuts and TR is same, unit elastic