## Demand and Supply

Read this chapter and attempt the "Try It" exercises. Also, complete the concept problems and the numerical problems at the end of the chapter. This chapter will help you gain familiarity and competencies with regard to basic demand and supply concepts. At a minimum, you should be able to list the factors that shift the demand curve and those that shift the supply curve. Make sure to carefully study the difference between demand and quantity demanded (and the difference between supply and quantity supplied).

### 3.3 Demand, Supply, and Equilibrium

#### KEY TAKEAWAYS

• The equilibrium price is the price at which the quantity demanded equals the quantity supplied. It is determined by the intersection of the demand and supply curves.
• A surplus exists if the quantity of a good or service supplied exceeds the quantity demanded at the current price; it causes downward pressure on price. A shortage exists if the quantity of a good or service demanded exceeds the quantity supplied at the current price; it causes upward pressure on price.
• An increase in demand, all other things unchanged, will cause the equilibrium price to rise; quantity supplied will increase. A decrease in demand will cause the equilibrium price to fall; quantity supplied will decrease.
• An increase in supply, all other things unchanged, will cause the equilibrium price to fall; quantity demanded will increase. A decrease in supply will cause the equilibrium price to rise; quantity demanded will decrease.
• To determine what happens to equilibrium price and equilibrium quantity when both the supply and demand curves shift, you must know in which direction each of the curves shifts and the extent to which each curve shifts.
• The circular flow model provides an overview of demand and supply in product and factor markets and suggests how these markets are linked to one another.