What is PED
Price elasticity of demand - The responsiveness of demand to a change in the price of the good
The values are always negative but economists write them as positive
What is the equation for PED
What is unitary elastic PED
PED = 1
Quantity demanded changes by the exactly the same percentagae as price
Elastic PED
PED>1
Quantity demanded changes by a larger percentage than price so demadn is relatively responsive to price
Inelastic PED
0<PED<1
Quantity demadned changes by a smaller percentage than price so demand is relatively unresponsive to price
Factors affecting PED
Why is PED Significant
PED and revenue
Elastic - Price and revenue have an inverse relationship. So if price increases then revenue will decrease and vice versa
Inelastic - Direct relationship. If price increases then so does revenue and vice versa
Unitary - Changes in price don’t affect total revenue
YED - equation and definition
The responsiveness of demand to a change in income
Values for YED
YED can take any value
YED<0 - Inferior good, so a rise in income will lead to a fall in demand for the good
0<YED - Normal good, a rise in income will lead to a rise in demand for the good
1<YED - Luxary good, it is a type of normal good
Significance of YED
XED - definition and equation
The responsiveness of demadn for one product (A) to the change in the price of another product (B)
Values for XED
XED can take any value
XED>0 - Subsitutes, an increase in the price of good B will increase demadn for good A. Such as Coke and Pepsi
XED<0 - Complementary goods, an increase in the price of good B will decrease demadn for good A. Such as DVDs and DVD players
XED = 0 - Unrelated goods, a change in price of good B has no impact on good A
The larger the integer the stronger the relationship between the two
Significance of XED
Firms need to be aware of their competition and those producing complementary goods. They need to know how price changes by other firms will impact them so they can take appropriate action
PES - definition and equation
The responsiveness of supply to a change in price of the good
Values for PES
PES is always positive
0<PES<1 - Inelastic PES, the quantity supplied changes by a smaller percentage than price so supply is relatively unresponsive to price. The curve will be steep starting on the x axis
1<PES<∞ - Elastic PES, the quantity supplied changes by a larger percentage than price so supply is relatively responsive to price. The curve will be more sloping starting on the y axis
PES = 1 - Unitary PES, quanitty supplied changes by exactly the same percentage as price. This would be shown as a curve which starts in the origin, is steeper than an elastic curve but more sloping than an inelastic curve
S1 - Unitary
S2 - Elastic
S3 - Inelastic
Factors affecting PES