Question

Difficulty: MediumIndifference Curves and Their Properties

A consumer adjusting their bundle of goods moves along an indifference curve, giving up 44 units of Good YY to obtain 22 additional units of Good XX without changing their total level of satisfaction. What is the Marginal Rate of Substitution of Good XX for Good YY (MRSxyMRS_{xy}) over this range?

  1. 2.02.0Answer
  2. B
    0.50.5
  3. C
    6.06.0
  4. D
    1.01.0

Answer

The Marginal Rate of Substitution (MRSxyMRS_{xy}) is equal to 2.02.0.
The Marginal Rate of Substitution of XX for YY (MRSxyMRS_{xy}) measures the units of Good YY a consumer must sacrifice to gain one additional unit of Good XX while keeping total utility constant. Here, sacrificing 44 units of YY for 22 units of XX gives an average rate of 42=2.0\frac{4}{2} = 2.0.

Step-by-Step Solution

1
Identify the change in quantity of Good YY (ΔY\Delta Y) and Good XX (ΔX\Delta X)
ΔY=4\Delta Y = -4 (reduction of 4 units of YY) and ΔX=+2\Delta X = +2 (gain of 2 units of XX)
The consumer gives up YY in exchange for XX to remain on the same indifference curve.
2
Apply the Marginal Rate of Substitution formula
MRSxy=ΔYΔX=(42)=2.0MRS_{xy} = -\frac{\Delta Y}{\Delta X} = -\left(\frac{-4}{2}\right) = 2.0
The magnitude of the slope of the indifference curve represents the rate at which YY is substituted for XX.

Key Concept

Marginal Rate of Substitution (MRS) along an Indifference Curve
Estimated Time:1m 0s
Rate this question