00:01
So here we're talking about elasticity.
00:02
And an elasticity is a response percent over a, say, shock percent, right? so something happens, right? something happens and then something else responds, and elasticity captures how much that thing responds in response to the shock.
00:21
So for a, we have the percentage change in income, y, is equal to 10 percent.
00:27
We have the percentage change in quantity demanded is equal to minus 4%.
00:32
So the elasticity is how much the quantity responds to the income shock.
00:38
So you suddenly get a 10 % raise.
00:40
How do you change your buying habits, right? minus 4%, 10%.
00:45
The income elasticity of demand is minus 0 .4, right? for b, we have a very similar thing.
00:54
We have income now is going from 60 ,000 to 65 ,000...