Transcript Equilibrium

Equilibrium
Market Demand
► This
is the total demand of all individual
consumers in a market at a given time for
all prices.
► It is found by horizontally adding all
individual demand schedules or curves
P
2
+
1
2
P
2
2
=
1
D
1
P
Q
D
1
2 Q
D
1
2
4
Q
Market Supply
► This
is the total Supply of all individual
producers in a market at a given time for
all prices.
► It is found by horizontally adding all
individual supply schedules or curves
P
P
2
S
1
+
P
S
2
=
2
Q
S
1
1
1
2
1
2 Q
2
4
Q
Where Demand and Supply Meet
► Equilibrium
is the point where Demand and
Supply cross
► Market equilibrium determines the price
► At this price quantity supplied exactly equals
quantity demanded so everyone prepared to
buy at that price gets what they want and
everyone prepared to sell at that price does.
Market Equilibrium
Market equilibrium occurs at
the price where the quantity
demanded equals the
quantity supplied. This
occurs at Pe. At this price
both quantity demanded and
quantity supplied is Qe.
Equilibrium is a state of
balance. There are no
shortages or surpluses.
P
s
Pe
d
Q
Qe
Excess Supply (Surplus)
s
P
P*
d
0
Qd
Qs
Q
At price p* quantity demanded
(Qd) is less than quantity
supplied (Qs). There is an
oversupply or a glut. (of Qs Qd) The market is in
disequilibrium and is not stable.
Market forces ( excess supply)
will tend to force prices down.
► This
is not a stable price
► The producer will want to sell their excess
stock so they will drop the price
► Consumers will react to lower prices by
buying more (move along the curve)
► This will continue until equilibrium is
regained where supply equals demand
Excess Demand (Shortage)
At price P* quantity
demanded is greater than
quantity supplied. There are
shortages (of Qd - Qs). At
this price there is not enough
quantity supplied to satisfy
the quantity demanded. The
excess demand tends to push
prices up.
S
P
P*
D
0
Qs
Qd
Q
Excess Demand
► This
is not a stable price
► The Consumers want to buy more of the
goods so they are prepared to pay higher
prices (move along the curve)
► Producers will react to higher prices by
supplying more (move along the curve)
► This will continue until equilibrium is
regained where supply equals demand
► When
Market reactions to
Disequilibrium
the market is not in equilibrium we call this a
disequilibrium.
► When
the market is in a disequilibrium, there will be
pressure on the market.
► These
pressures are from the needs of consumers for
goods and services (demand) and the need of
producers to sell their goods and services (supply)
► These
pressures are known as
market forces or ‘the invisible hand’.