Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Walt considers x and y to be perfect substitutes. They originally cost $10 and $

ID: 1190604 • Letter: W

Question

Walt considers x and y to be perfect substitutes. They originally cost $10 and $9 respectively. His income is $720. One day the price of x drops to $8.

a.

The income effect increases the quantity of y by 90.

b.

The substitution effect increases the quantity of y by 80.

c.

The substitution effect increases the quantity of x by 90.

d.

The income effect increases the quantity of x by 80.

e.

None of the above.

a.

The income effect increases the quantity of y by 90.

b.

The substitution effect increases the quantity of y by 80.

c.

The substitution effect increases the quantity of x by 90.

d.

The income effect increases the quantity of x by 80.

e.

None of the above.

Explanation / Answer

Given

Px= $10, Py= $9

Income = $720

As x and y are perfect substitutes, decrease in price of any of the goods will make walt to shift from high price to low price good

As cost of y is less, he purchases 720/9 = 80 units of good y

After the price of x drops to 8

Px= 8, Py= 9

Walt shifts to good x, as they are perfect substitutes and purchases x

units of x = 720/8

= 90

Therefore, option c is correcr, as substitution effect increases quantity of x by 90