(1) Shifts versus Movements along the Supply curve

Understanding Supply Curves

Supply Curve Definition: Represents the relationship between the market price and the quantity supplied, assuming ceteris paribus (all else held constant).
Axes of the Supply Curve:
- Vertical Axis: Price of the good.
- Horizontal Axis: Quantity supplied.

Movements Along the Supply Curve

Occur due to changes in price.
- Example:
  - Price increases from $6 to $8:
    - Quantity supplied increases from 6 to 10 units (movement along the curve).
    - This is termed an increase in the quantity supplied.
  - Price decreases from $8 to $6:
    - Quantity supplied decreases from 10 to 6 units (movement along the curve).
    - This is termed a decrease in the quantity supplied.

Shifting the Supply Curve

Shifts occur due to changes other than price that affect supply.
- Decrease in Supply:
  - Represented as a leftward shift (e.g., from S to S1).
  - At every price, the quantity supplied is now less:
    - Example: At $8, supply drops from 10 to 6 units.
  - Terminology Note: Use "decrease in supply" instead of "decrease in quantity supplied" when discussing shifts.
  - Causes may include:
    - Increased costs of production (e.g., capital/labor costs).
    - Firm exit from the industry.
    - Shock events (e.g., natural disasters).
Increase in Supply:
- Represented as a rightward shift (e.g., from S to S2).
- At every price, the quantity supplied is now more:
  - Example: At $8, supply rises from 10 to 14 units.
- Causes may include:
  - Technological advancements improving efficiency.
  - Decrease in production input costs (capital/labor).
  - Entry of new firms in the market.

Summary of Key Concepts

Movements along the supply curve are driven by price changes (increase/decrease in the quantity supplied).
Shifts in the supply curve are driven by non-price factors affecting overall supply (increase/decrease in supply).
Understanding these dynamics is crucial for analyzing market behavior.