SFU Beedie courses only. See the course list →
Business TutorBusiness Tutor
← Everything for ECON 103
ECON 103

What changes the market price?

Move supply and demand to see how prices, quantities, shortages and surpluses respond. Learn to separate shifts from movements, then solve 10 questions with worked answers.

Buyers and demand · Step 1 of 12

Price changes the quantity buyers want

Move along demand
Price ($ per pouch)
QQ₀P₀PABD
Pouches (quantity)
D. Marked point A. Marked point B.
D: demand
A: 15 pouches at $30B: 18 pouches at $24
In invented Willow Bay, buyers use glowleaf pouches to carry craft pieces. Demand is P = 60 − 2 × Q, where P is dollars per pouch and Q is pouches. Other things equal, a higher own price reduces quantity demanded: this is the law of demand.
Try it: Move price and follow the point along the same demand curve.
Pouch price$30
Price
$30
Buyers want
15
Change type
Along demand
Qd = (a − P) ÷ b.
Qd = (60 − 30) ÷ 2 = 15 pouches.
At the reference price of $24: (60 − 24) ÷ 2 = 18 pouches.
The curve stays fixed; the selected price changes quantity demanded.
Check yourself
Only the pouch’s own price rises. What changes?

Exam coming up and shifts versus movements still trip you up?

Bring your problem sets. We work through them together until every type feels routine.

FAQ

Questions, answered.

Still unsure about something? Message us and you will hear back within a day.

See all questions
  • In person, we meet at the SFU Burnaby campus or in a private meeting room near Brentwood in Burnaby. Online sessions run on Zoom. You choose when you book.