The only way a consumer can optimize at a corner of her budget is if at least one of the goods is not essential.

Question

Quizplus · Accepted Answer

If all goods in the budget are essential, the consumer cannot optimize only at a corner of the budget constraint. This is because she needs to allocate some amount of her budget to purchase every essential good. However, if at least one good is not essential, the consumer can choose to allocate zero budget to that good and optimize at the corner of her budget constraint where only the essential goods are being consumed.

The Only Way a Consumer Can Optimize at a Corner