00:01
Here we're going to be working on calculating elasticity, both price elasticity and income elasticity based upon this demand schedule that's been given to us.
00:11
This is the demand for pizza based upon two different income levels, an income of $20 ,000 and an income of $24 ,000.
00:19
Let's go ahead and start by calculating the price elasticity of demand as the price increases from $8 to $10 for price of pizza, and we're going to do this for each income level that we have here.
00:30
Start with our first one when our income is equal to 20 ,000.
00:34
Let's keep in mind here that what we're doing is calculating, so from 8 to 10, right? so we're going to be using these two quantities or prices and these are our quantities we're going to be using.
00:45
And you can see up top i've also given us the function or the formula that we can use here to calculate it, which makes it pretty straightforward.
00:53
So we can see that our, let's start with our q2.
00:56
So that's going to be our second quantity.
00:58
So we increase to 10.
01:00
So that's our, this is our second one and eight would be our first.
01:04
So the quantity, when the price is 10, is equal to 32.
01:09
And we can subtract that from our q1.
01:12
So when our price is $8, 40 pizzas were demanded, that gets divided by its midpoint.
01:21
So we do that.
01:22
We take 32 plus 40, and then divide it by two.
01:28
So we're calculating our elasticity here using the midpoint method, which is the most accurate way of doing it, to guarantee that we have the same base as we work through.
01:36
But either way, so that gives us our numerator.
01:39
Our denominator then is given by our second price minus our first price.
01:44
So we just said that our second price is $10, minus the first one of $8, and then that also gets divided by its midpoint.
01:52
So we have 10 plus 8 divided by 2 on our denominator.
01:58
We can go ahead and simplify this.
02:00
It'll give us negative 8 over 36 for a numerator divided by 2 over 9 for a denominator.
02:12
Simplifying that even further, we get price elasticity equal to negative 1.
02:21
Now we can go ahead and do the same thing for our second income bracket where our income is equal to $24 ,000.
02:27
So in this case, our numerator is going to be $45 ,000.
02:35
Minus 50 because you can see when our price is equal to 10 we there were 45 pizzas demanded and when our price is equal to 8 there are 50 pizzas demanded dividing that by its midpoint so 45 plus 50 divided by 2 all of this gets divided by our prices so this is actually going to be the same as what we found over in our first income right in here because our prices are still 10 and 8 so that's not going to really.
03:08
So i'm actually just going to go ahead and write on our denominator 2 over 9 because remember that's what we ultimately simplified this to was 2 over 9.
03:17
So that's just to save some space and some time on our end.
03:20
And now we can simplify what we have in our denominator or on our numerator.
03:25
And that ends up being negative 5 all over 47 .5 still over that 2 over 9.
03:34
And that gives us a price elasticity equal to negative 0 .47...