Demand
The quantity of a good or service consumers are both able and willing to buy at a given price in a particular period of time. The higher the price of a product the lower the demand and vice versa.
Law of demand
States that the quantity demanded of a product will fall if the price increases and vice versa.
What are the assumptions underlying the law of demand?
Income effect
Substitution effect
Law of diminishing marginal utility
Income effect
As the price of a product falls, consumers real income increases. They are able to buy more product at a lower price
Substitution effect
As the price of a good or service falls, more customers are able to buy the product, so choose this over rival or substitute products that they might have previously bought.
The law of diminishing marginal utility
As individuals consume more of a particular good or service, the satisfaction gained from the additional unit of consumption declines, so customers will only purchase more at lower prices
Market
Any place where transactions take place between a buyer and a seller
Market demand curve
Refers to the sum of all individual demand for a product at each price level
Non-price determinants of demand
Income
Tastes and preferences
Future price expectations
Price of related goods
Number of consumers
Normal goods
Products that consumers buy more of when their real incomes rise
Inferior goods
Products that the demand falls when consumers real income rise. For example, used cars
Complementary goods
Products that are jointly demanded. For example, milk and cereal
Substitutes
Products that are competitive in demand because they can be used in place of one another.
Contraction
An increase in price along the demand curve
Expansion
A fall in price along the demand curve