1. Law of Demand A. When one good can be used in the place of another good. 2. Law of Supply B. When quantity supplied equals quantity demanded. 3. Equilibrium C. When the quantity demanded of a good or service is greater than the quantity supplied. 4. Substitutes D. When the price goes up, quantity supplied goes up. When the price goes down, quantity supplied goes down. 5. Complements E. When the quantity supplied of a good is greater than the quantity demanded. 6. Shortage F. A price goes up, quantity demanded goes down. When the price goes down, quantity demanded goes up. 7. Surplus G. When a good can be used together with another good