a) Demand

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 amount of a good or service that consumers are willing and able to purchase at a given price and time

demand curve

a change in only the price causes

• a change in the quantity demanded

• a movement move along the demand curve

price decreases

• quantity demanded increases

• extension in quantity demanded

price increases

• quantity demanded decreases

• contraction in quantity demanded

the conditions of demand = the factors other than price that cause a change in demand

a change in the conditions of demand → a change in demand

if demand decreases → demand curve shifts left

if demand increases → demand curve shifts right

examples of conditions of demand

• a change in the population size

• a change in real consumer income

• a change in the price and availability of substitute and complementary goods