Q. Why cannot both of the commodities be inferior at the same time? What happens if both are inferior?
Answer: Under the classical consumer’s equilibrium model, both commodities can not be inferior at the same time. One of them may be inferior. It is because the consumer is assumed to be rational, who tries to maximize the utility by utilizing the full budget or resource.
For this, the consumer allocates the given resource between the two commodities to maximize utility. So, if both of them are inferior, it does not hold the consumer’s utility maximization by full utilization of resources, and both of the commodities are inferior, then the consumer reduces the quantity of both, which makes some income or resource unutilized or idle. If such an idle resource can be used for the consumption of either one, it increases the utility. It means the consumer always chooses between two of the commodities, which makes the selected commodity normal or superior to the other.