Elasticity along a Linear Demand
Curve
Price
D = -
perfectly
elastic
a/b = 14.3
P
D = -b
Q
where b = 20
elastic: D < -1
11.44
D = -4
a/(2b) = 7.15
inelastic: 0 > D >
-1
perfectly
inelastic
unitary elastic: D = -1
3.3
D = -0.3
0
a/5 = 57.2
a/2 = 143
220
D
Elasticity along a Linear Demand
Curve
Price
D = -
perfectly
elastic
a/b = 14.3
P
D = -b
Q
where b = 20
elastic: D < -1
11.44
D = -4
a/(2b) = 7.15
inelastic: 0 > D >
-1
perfectly
inelastic
unitary elastic: D = -1
3.3
D = -0.3
0
a/5 = 57.2
a/2 = 143
220
D