Answer:
Substitution Bias
Step-by-step explanation:
CPI stands for Consumer Price Index which defines a measure of average prices consumer products.
Now if the prices among the category of consumer products vary not so relatively to one another then it s a bit difficult to measure CPI accurately.
The substitution bias can create an issue in consumer Price Index that when costumers go for the subsititure option, due to infaltion a customer can buy a cheaper product rather than sticking to same old product or choice