Economics Fundamentals — Every choice has a price, even when no money changes hands.
Economics starts from one fact: resources are limited but wants are not. That gap, called scarcity, forces every person, business, and government to make choices.
Opportunity cost: The value of the next best option you give up when you make a choice. Even free time has a cost.
If you spend Saturday studying instead of working an $80 shift, the opportunity cost of studying is that $80, even though no money left your pocket.
Comparative advantage: Producing something at a lower opportunity cost than someone else. It is why trade and specializing benefit both sides.
A sunk cost is money already spent and gone. Good decisions ignore it and focus on future costs and benefits.
15 practice questions with explanations. Free, and no account is needed to start.