GrowlWolfGirl

demand是the quantities a buyer is willing and able to buy at different price.
而quantity demanded是particular price

我吾系好明咩意思,可吾可以俾幾個例子我?
我想分清佢！！thx!

samwong001

Demand is similar to "demand curve"
Quantity demanded is similar to "a point on demand curve"

you may think about the difference between "change in demand" and "change in quantity demanded"
change in demand : shift the whole demand curve
change in quantity demanded : movement along the demand curve (change in price-quantity pair)

yingjaiv0v

Demand = quantity demanded at every price level
i.e the whole curve

Quantity demanded = the quantity of goods you are willing to buy at a give price
i.e one point on the demand curve

An increase or decrease in the price of the good DOES NOT affect the demand for it,
as it only affects the quantity of goods willing to buy at that price (only ONE point),
e.g at $20, Qd = 10 while at $22, Qd =8

A change in demand have to be caused by other factors,
as it implies a change in quantity demanded at every price level,
but not only ONE.

phamton1984

DEMAND 係指在不同價格下 相對需求的改變
而QD 是指在指定價位時的 相對需求
所以 DEMAND 是整條線
而QD是指線上的其中一點