Part B | How Competitive Markets Work

Prices can coordinate buyers and sellers

Part B reveals how markets solve the coordination problem from Part A. Through the elegant dance of supply and demand, prices emerge to coordinate economic activity and guide society toward efficiency. These aren't just abstract curves—they're the invisible forces that determine what gets produced, who gets what, and how resources flow through the economy. By the end of Part B, you'll understand why competitive markets are one of humanity's greatest innovations for creating prosperity.

Block B1 | Demand

Demand curves show how much consumers are willing to buy at each price.

Episode B1 thumbnail

Episode B1 This video introduces the demand curve as a way of organizing buyers' preferences.

  1. Exercise B1 in class

  2. Vignette B1 recitation

  3. Homework B1 home

    Due Sun Sep 20

Block B2 | Supply

Supply curves show how much producers are willing to sell at each price.

Episode B2 thumbnail

Episode B2 This video introduces the supply curve and how it helps answer Part B's questions.

  1. Exercise B2 in class

  2. Vignette B2 recitation

  3. Homework B2 home

    Due Sun Sep 20

Block B3 | Equilibrium

Markets find the equilibrium price where quantity supplied equals quantity demanded.

Episode B3 thumbnail

Episode B3 This video introduces shortage and surplus and the incentives of buyers and sellers to move prices toward equilibrium.

  1. Simulating a Market optional

  2. Exercise B3 in class

  3. Vignette B3 recitation

  4. Homework B3 home

    Due Sun Sep 27

Block B4 | Efficiency

Competitive markets maximize total surplus, achieving social efficiency.

Episode B4 thumbnail

Episode B4 This video introduces government price controls to show that the market maximizes total surplus in some environments.

  1. Exercise B4 in class

  2. Vignette B4 recitation

  3. Homework B4 home

    Due Sun Sep 27

Block B5 | Elasticity

Elasticity measures how responsive quantity is to changes in price, income, or other factors.

Episode B5 Elasticity measures responsiveness

  1. Exercise B5 in class

  2. Vignette B5 recitation

  3. Homework B5 home

    Due Sun Oct 4

Block B6 | Comparative Statics

Comparative statics analyzes how equilibrium changes when supply or demand conditions shift.

Episode B6 How markets respond to changes

  1. Exercise B6 in class

  2. Vignette B6 recitation

  3. Homework B6 home

    Due Sun Oct 4

Block B7 | Tariffs

International trade improves welfare but also creates winners and losers, which can lead to political pressure for protectionist policies like tariffs.

Episode B7 thumbnail

Episode B7 International Trade

  1. Exercise B7 in class

  2. Vignette B7 recitation

  3. Homework B7 home

    Due Sun Oct 4

Checkpoint B

Checkpoint B covers everything in Part B. If you understand the concepts and do the work in the Vignettes, Homework, and Demo, you're going to be in good shape on the Checkpoint.

Demo B thumbnail

Demo B Walkthrough Attempt Demo B first, then walk through with me.

  1. Demo B home

  2. Checkpoint B in class

    Wed Sep 30

  3. Reattempt TBA