effects of shifts in demand and supply curves on equilibrium price and quantity

The Interaction of Demand and Supply

1️⃣ What is Demand?

Demand is the amount of a product that buyers want to buy at different prices. Think of it like a line of students waiting for a new video game. The higher the price, the fewer students are willing to buy it. 📉

2️⃣ What is Supply?

Supply is the amount of a product that sellers are ready to sell at different prices. Imagine a bakery that can bake more cupcakes when the price is higher. The higher the price, the more cupcakes the bakery wants to sell. 📈

3️⃣ Equilibrium: Where Demand Meets Supply

The equilibrium price (\$P^*\$) and quantity (\$Q^*\$) are where the demand curve and supply curve intersect. At this point, the amount buyers want equals the amount sellers want to sell. The market is balanced. ⚖️

4️⃣ How Shifts Affect Equilibrium

  1. Demand increases (shift right): More people want the product at every price. \$P^*\$ rises, \$Q^*\$ rises. 🎉
  2. Demand decreases (shift left): Fewer people want the product at every price. \$P^*\$ falls, \$Q^*\$ falls. 😞
  3. Supply increases (shift right): Sellers can supply more at every price. \$P^*\$ falls, \$Q^*\$ rises. 🏭
  4. Supply decreases (shift left): Sellers can supply less at every price. \$P^*\$ rises, \$Q^*\$ falls. 🏭

5️⃣ Visualising Shifts with a Table

ShiftDemandSupplyEffect on \$P^*\$Effect on \$Q^*\$
Demand ↑RightNo change
Demand ↓LeftNo change
Supply ↑No changeRight
Supply ↓No changeLeft

6️⃣ Quick Quiz

  • What happens to \$P^*\$ if the supply curve shifts to the right? Answer: It falls.
  • Which shift would cause both \$P^*\$ and \$Q^*\$ to rise? Answer: Demand increases.
  • How does a decrease in supply affect the market? Answer: \$P^*\$ rises, \$Q^*\$ falls.

7️⃣ Takeaway

Remember: Shifts change the curves, while movements along the curves are caused by price changes. Understanding these helps you predict how real markets will react to events like a new technology, a change in consumer taste, or a government tax. 🚀