Samantha goes to the grocery store to make her monthly purchase of ginger ale. As she enters the soft drink section, she notices that the price of ginger ale has increased 15 percent, so she decides to buy some peppermint tea instead. To which problem in the construction of the CPI is this situation most relevant?

The Consumer Price Index (CPI) is a measure that examines the weighted average of prices of a basket of consumer goods and services, such as transportation, food, and medical care. It is calculated by taking price changes for each item in the predetermined basket of goods and averaging them.

The substitution bias is a weakness in the Consumer Price Index that overstates inflation because it does not account for the substitution effect, when consumers choose to substitute one good for another after its price becomes cheaper than the good they normally buy.

Samantha decides to buy some peppermint because of the 15% inflation on the price of ginger ale, therefore, this situation is most relevant to SUBSTITUTION BIAS in the construction of CPI.