Demand
- Demand is the amount of a good/service that a consumer is willing and able to purchase at a given price in a given time period
- If a consumer is willing to purchase a good, but cannot afford to, it is not effective demand
- If a consumer is willing to purchase a good, but cannot afford to, it is not effective demand
- A demand curve is a graphical representation of the price and quantity demanded (QD) by consumers
- If data were plotted, it would be an actual curve, however economists simplify curves in their sketches into straight lines so as to make analysis easier
- If data were plotted, it would be an actual curve, however economists simplify curves in their sketches into straight lines so as to make analysis easier
Movements Along A Demand Curve
- If price is the only factor that changes (ceteris paribus), there will be a change in the QD
- This change is shown by a movement along the demand curve
A demand curve showing a contraction in quantity demanded (QD) as prices increase and an extension in quantity demanded (QD) as prices decrease
Diagram Analysis
- An increase in price from £10 to £15 leads to a movement up the demand curve from point A to B
- Due to the increase in price, the QD has fallen from 10 to 7 units
- This movement is called a contraction in QD
- A decrease in price from £10 to £5 leads to a movement down the demand curve from point A to point C
- Due to the decrease in price, the QD has increased from 10 to 15 units
- This movement is called an extension in QD
- The law of demand captures this fundamental relationship between price and QD
- It states that there is an inverse relationship between price and QD
- When price rises the QD falls
- When prices fall the QD rises
- It states that there is an inverse relationship between price and QD
- This relationship partly explains why the demand curve is downward sloping