Ch.2 Summary

Overview

Theory of Demand and Supply

This interactive guide explores the foundational concepts of market economics. Use the sidebar to simulate market behaviors.

Demand

Desire backed by purchasing power and willingness to buy.

Supply

Quantities sellers are willing/able to provide at given prices.

Equilibrium

Point where Market Demand = Market Supply (\(Q_d = Q_s\)).

Law of Demand

Inverse relationship between Price and Quantity Demanded.

Law of Supply

Positive relationship between Price and Quantity Supplied.

Shortage

\(Q_d > Q_s\). Occurs when Price < Equilibrium.

Surplus

\(Q_s > Q_d\). Occurs when Price > Equilibrium.

Demand Explorer

Simulate movements and shifts.

1. Law of Demand (Movement)

Change price to see movement along the curve.

Price: Birr 3, Quantity: 9 kg

2. Demand Shifters (Shift of Curve)

Non-price factors shift the entire curve.

Base demand curve (D0).

3. Elasticity Calculator

\( E_d = \frac{Q_1 - Q_0}{Q_0 + Q_1} \div \frac{P_1 - P_0}{P_0 + P_1} \)

Supply Explorer

Theory of Supply Visualization.

1. Law of Supply (Movement)

Higher prices incentivize sellers to supply more.

Price: Birr 20, Quantity: 80 kg

2. Supply Shifters (Shift of Curve)

Base supply curve (S0).

Market Equilibrium Simulator

Where Demand meets Supply.

1. Finding Equilibrium

Example: \( Q_d = 100 - 2P \) and \( Q_s = 2P - 20 \).

Move the slider to create Surplus or Shortage.

2. Equilibrium Shifts

What happens to Price and Quantity when curves move?

Original Equilibrium (E0): P=30, Q=40

New Equilibrium (E1): P=30, Q=40

Select a shift to see impact.