M

a) demand curves

a) the distinction between movements along a demand curve and shifts of a demand curve

b) the factors that may cause a shift in the demand curve (the conditions of demand)

demand = the value of a good or service that consumers are willing and able to purchase at a given price and time

on a demand curve

  • y-axis = price

  • x-axis = quantity demanded

  • demand curve = constant and negative gradient

    • consumers would purchase less goods or services at higher prices in order to maximise their utility

a change in only the price

  • causes a change in the quantity demanded

  • and causes the position to move along the demand curve

if the price decreases

  • the quantity demanded increases

  • so there will be an extension in the quantity demanded

if the price increases

  • the quantity demanded decreases

  • so there will be a contraction in the quantity demanded

the conditions of demand = the factors other than price that change the demand

  • a change in the conditions of demand

    • causes the demand curve to shift left if the demand decreases or shift right if the demand increases

    • and does not change the gradient of the demand curve

examples of some conditions of demand

  • a change in the population size

  • a change in real income per capita

  • a change in the price of substitute or complementary goods