Supply, Demand and Equilibrium Flashcards
Define demand
The quantity of a good or service that consumers are willing and able to purchase at any given price
Why is demand downward sloping
For consumers, price and quantity have an inverse relationship: as price increases, fewer units are demanded:
The income effect
The substitution effect
Diminishing marginal utility
What is the income effect (demand)
When prices go up your income is worth less- your income has less purchasing power
The substitution effect (demand)
If hobnobs ⬆️ by 50p, you buy digestives- the OC of 1 good, in terms of what you could have bought in the sub, goes up- so if p ⬆️, the good more expensive relative to the sub
What is diminishing marginal utility (group level) (demand)
Group level: Each new consumer brought into the market gains less utility from consuming a good than the last 1 did, so to attract new consumers, ⬇️ price so they would be willing to pay
What is diminishing marginal utility (individual level) (demand)
The more an individual consumes of a gd, the less utility gained from extra unit consumed so the less you’ll pay for it- so p must fall.
For both: the D curve represents a consumers willingness to pay, which depends on utility
What are Movements along the demand curve
Caused by a change in P and represents a change in qd
Contraction ⬅️ (less qd)
Extension ➡️ (more qd)
What is a shift in the demand curve
Signifies ⬆️ in the qd at any given p
At all p more of the good is sold than before
What is a shift in demand caused by
Anything other than price, e.g. seasonal, or a good marketing campaign
What are movements in the demand curve caused by?
What most commonly causes the change in price is a shift in supply, or could be gov policy e.g. a min price
Shift in demand caused by:
Complements changed in price
If P of the complement ⬇️ then demand for other good ⬆️
e.g. cereal and milk
Shift in demand caused by:
Change in price of sub
If p sub ⬆️ then demand for other good shifts out
Shift in demand caused by:
Derived demand
E.g. cows and cattle feed- if D for beef goes up,then need more cattle feed
Shift in demand caused by:
Changes in income
If income increases, nearly everything shifts out, apart from like spam
Shift in demand caused by:
Changes in population
Ageing population means more demand for stuff like care homes