Question

When​ Alex's income increased from ​$2,000 to ​$4,000​, he increased his consumption of bagels from 6 to 10 a month and decreased his consumption of donuts from 15 to 9 a month. Calculate​ Alex's income elasticity of demand for bagels and donuts.

Answer 1

Answer:

For Bagels = 1.33

For Donuts = -1.33

Explanation:

Using the midpoint method, Alex's percentage change in income is given by the difference in income divided by the average income:

$\%I =\frac{\ 4,000-\ 2,000}{\frac{\ 4,000+\ 2,000}{2}}\\\%I=66.67\%$

Alex's percentage change in demand for both bagels and donuts is given by the difference in the quantity consumed divided by the average consumption:

$\%B =\frac{10-6}{\frac{10+6}{2}}\\\%B=50.00\%\\\%D =\frac{9-15}{\frac{15+9}{2}}\\\%D=-50.00\%$

Alex's income elasticity of demand for bagels and donuts, respectively, is:

$E_B=\frac{\%I}{\%B}=\frac{66.67\%}{50\%} \\E_B=1.33\\\\E_D=\frac{\%I}{\%D}=\frac{66.67\%}{-50\%} \\E_D=-1.33$

His income elasticity of demand for bagels is 1.33, while for Donuts it is  -1.33.