Economics 1st Edition by Dean Karlan,Jonathan Morduch

تمرين 7

Suppose that the price of peanut butter rises from $2 to $3 per jar.
a. The quantity of jelly purchased falls from 20 million jars to 15 million jars. What is the cross-price elasticity of demand between peanut butter and jelly? Are they complements or substitutes?
b. The quantity of jelly purchased rises from 15 million jars to 20 million jars. What is the cross-price elasticity of demand between peanut butter and jelly? Are they complements or substitutes?