Demand, supply and the market Flashcards
What are demand + supply used to do?
analyse the determinants of the price and quantity of an individual good or service
What is an endogenous variable?
where the value is determined WITHIN the model
2 key ones = the price and quantity of a good or service
What is an exogenous variable?
where the value is determined OUTSIDE the model
these are factors that cause a shift in the demand or supply curve
What happens if real income increases?
people have more to spend
If real income INCREASES, what happens to the demand curve?
the demand curve shifts to the right
↑ causes shift to →
↑→ right angle for RIGHT
If real income DECREASES, what happens to the demand curve?
the demand curve shifts to the left
↓ ←
What are complements?
goods that feed off each other
eg car and petrol
you can’t drive a car with out petrol
if price of petrol ↑, less people would buy cars
the demand curve for cars would shift inwards
What movement does ENDOGENOUS factors always cause?
a movement up or down the demand or supply curve
movement ALONG
What movement does EXOGENOUS factors always cause?
the demand or supply curve to shift inwards or outwards
shifting of the demand or supply curve
How do you describe the demand curve?
D for downward sloping
What is on the y axis (vertical axis) of the demand/supply curve?
price
What is on the x axis (horizontal axis) of the demand/supply curve?
quantity
Why is the demand curve downward sloping?
bc if you lower the price of the good, then more of the good is demanded
this is bc when the price is cheaper, existing consumers consume as well as new consumers
What does the demand curve represent?
planned purchases (not what actually happens)
What are key assumptions of the demand curve? (3)
1) no single consumer is able to influence the market price
2) there is an infinite number of consumers and producers in the market
3)all other influences on demand are assumed to be constant apart from the quantity and the price
What does the assumption that no single consumer is able to influence the market price mean?
consumers have to take prices as given, they’re only able to choose the quantity of goods that they’re willing to purchase
How would you describe the supply curve?
Upward sloping
this tells us that as the price of the good increases, the quantity supplied of the good increases
Why is a company likely to supply more if the price of a good increases?
because they have a chance to make a higher profit
What does the supply curve represent?
the willingness to supply of sellers at each possible price
What are the key assumptions of the supply curve?
sellers are price takers
(no single seller is able to influence the market price, sellers are only able to choose quantity)
Is the assumption that sellers are price takers realistic?
no
the real world is more complex than the simplified one that this model suggests
in the real world there are many markets where only a handful of suppliers exert a huge pressure on prices eg single water supply
What is the demand supply model a simplification of?
a complex world
What is achieved at the point of intersection between the demand and supply curve?
market equilibrium
What does the equilibrium point act as?
a centre for gravity for market prices
What do Comparative Statics involve?
comparing the equilibrium price and quantity before and after a change to the market
With Comparative Statics, what do we examine? (2)
1)the comparative statics of a shift in the demand and supply curves
2)how the slope of the demand/supply curve affects the equilibrium price + quantity that emerges after the change to the market
What does a steeper supply curve mean?
higher price rise and smaller increase in quantity
bc price is on y axis
What does a flatter supply curve mean?
lower price rise and bigger increase in quantity
bc quantity is on x axis
What does the extent to which the price and quantity depend on?
the slope of the demand or supply curve
What does a steeper DEMAND curve mean?
bigger price drop and smaller increase in quantity
bc downward sloping
What does a flatter DEMAND curve mean?
smaller price drop and bigger increase in quantity