1. Know the difference! Changes in demand/supply versus changes in “quantity demanded”/ “quantity supplied”

2. Changes in “quantity demanded” Demand Schedule Price of chocolate bars ($) Quantity demanded of chocolate bars (per week) 52 44 36 28 110 Chocolate bars 1 2 3 4 5 Price 246810 Quantity D (Demand) A change in price always causes a change in “quantity demanded.”

3. Changes in demand Demand Schedule Initial price of chocolate bars ($) Initial quantity demanded of chocolate bars (per week) Price of chocolate bars after ∆ in income($) Quantity demanded of chocolate bars (per week) after ∆ in income($) 5254 4446 3638 28210 1 112

4. Changes in demand Chocolate bars 1 2 3 4 5 Price 246810 D (Demand) A change one of the non-price determinants always causes a change in demand. D1 (Demand)

5. Know the lingo! When you write, “change in quantity demanded,” make sure you are referring to the result of a price change. When you write, “change (or shift) in demand,” make sure you are referring to the result of a change in a non-price determinant!

6. Supply works the same way! When you write, “change in quantity supplied,” make sure you are referring to the result of a price change. When you write, “change (or shift) in supply,” make sure you are referring to the result of a change in a non-price determinant!

7. End.