Demand. Demand is the quantity of a commodity a consumer is willing and able to buy.
-
Upload
blanche-lynch -
Category
Documents
-
view
217 -
download
2
Transcript of Demand. Demand is the quantity of a commodity a consumer is willing and able to buy.
DemandDemand
Demand is the quantity of a Demand is the quantity of a commodity a consumer is commodity a consumer is willingwilling
and and ableable to buy. to buy.
The law of demandThe law of demand
As the As the priceprice increases, the increases, the quantityquantity demanded decreases, demanded decreases, ceteris paribusceteris paribus..
This also works in the opposite direction This also works in the opposite direction e.g. Price down quantity upe.g. Price down quantity up
Ceteris paribusCeteris paribus means everything means everything else is held constant and only price is else is held constant and only price is allowed to change. We know in reality you allowed to change. We know in reality you can’t do this but just pretend.can’t do this but just pretend.
Demand SchedulesDemand Schedules
This is a table that shows the quantity of a This is a table that shows the quantity of a good or service a consumer is willing and good or service a consumer is willing and able to buy at each priceable to buy at each price
TITLETITLE: Lillie’s Demand for chips : Lillie’s Demand for chips per weekper week
LabelLabel: Price ($): Price ($) LabelLabel: Quantity: Quantity
11 55
22 33
33 22
44 11
Lilly's Demand for Chips
0
1
2
3
4
5
6
1 2 3 4
Quantity
Pri
ce (
$)
TALLTALL
TitleTitle
AxisAxis
LabelsLabels
LineLine
TALL helps us remember the key points to TALL helps us remember the key points to draw an accurate line graph.draw an accurate line graph.
Change in the Change in the QuantityQuantity Demanded Demanded
PricePrice is the only thing that will change the is the only thing that will change the quantity demanded.quantity demanded.
A change in price moves you along the Demand A change in price moves you along the Demand curve.curve.
An increase in price causes a decrease in the An increase in price causes a decrease in the QuantityQuantity demanded demanded
An decrease in price causes an increase in An decrease in price causes an increase in QuantityQuantity demanded demanded
Price and quantity move in Price and quantity move in opposite directionsopposite directions
LAW OF DEMANDLAW OF DEMAND
P
$
QD
As price decreases then quantity demanded increases or as price increases quantity
demanded decreases, ceteris paribus.
Do this nowDo this now
1.Construct a demand schedule based on the information above. Remember your labels2.Identify the quantity Rena would demand at the current price of $1.00. 3.Explain why Rena’s quantity demanded of peanut slabs falls as the price rises
D
D
Movement along the demand Movement along the demand curvecurve
We use the term quantity demanded when we are describing a change in price. This is illustrated by a movement along the demand curve.
Go to workbooks page 28. Read the box up the top and begin exercises below.
Price increases to 1.25
Show these effects
Locate new quantities and prices
Draw in arrowsLabel.
Q1
p1
Q2
p2
Market DemandMarket Demand
Is the total demand that all individual Is the total demand that all individual consumers in that market are willing and consumers in that market are willing and able to buy at various prices at a particular able to buy at various prices at a particular point in timepoint in time
How much the whole market will buyHow much the whole market will buy
Market Demand Schedules and Market Demand Schedules and CurvesCurves
Found (derived) by adding horizontally, all the Found (derived) by adding horizontally, all the individual consumers demand schedules and individual consumers demand schedules and curves. curves.
Demand Schedule for Cans of Soft Drink (weekly)
Price ($) Rebecca Quantity
Hilary Quantity
Maree Quantity
Market Quantity
.50.50 77 44 66
1.001.00 44 33 33
1.501.50 22 11 22
7+4+6 =17
4+3+3=10
2+1+2=5
Text Book page 24Text Book page 24
Questions 1-5Questions 1-5