Market Equilibrium

When the supply and demand curves intersect, the market is in equilibrium.  This is where the quantity demanded and quantity supplied are equal.  The corresponding price is the equilibrium price or market-clearing price, the quantity is the equilibrium quantity.

Market equilibrium is a situation when quantity demanded and quantity supplied are equal and there is no tendency for price or quantity to change

Putting the supply and demand curves from the previous sections together. These two curves will intersect at Price = $6, and Quantity = 20. In this market, the equilibrium price is $6 per unit, and equilibrium quantity is 20 units.
At this price level, market is in equilibrium. Quantity supplied is equal to quantity demanded ( Qs = Qd). 

Market is clear.


SURPLUS AND SHORTAGE :

If the market price is above the equilibrium price, quantity supplied is greater than quantity demanded, creating a surplus.  Market price will fall.

Example: if you are the producer, you have a lot of excess inventory that cannot sell. Will you put them on sale? It is most likely yes. Once you lower the price of your product, your product’s quantity demanded will rise until equilibrium is reached. Therefore, surplus drives price down.

If the market price is below the equilibrium price, quantity supplied is less than quantity demanded, creating a shortage. The market is not clear. It is in shortage. Market price will rise because of this shortage.

Example: if you are the producer, your product is always out of stock. Will you raise the price to make more profit? Most for-profit firms will say yes. Once you raise the price of your product, your product’s quantity demanded will drop until equilibrium is reached.  

Therefore, shortage drives price up.

If a surplus exist, price must fall in order to entice additional quantity demanded and reduce quantity supplied until the surplus is eliminated.  If a shortage exists, price must rise in order to entice additional supply and reduce quantity demanded until the shortage is eliminated.

 EXAMPLE

If the market price (P) is higher than $6 (where Qd = Qs),
for example,  P=8, Qs=30, and Qd=10.
Since  Qs>Qd, there are excess quantity supplied  in the
market, the market is not clear. Market is in surplus.
THE PRICE WILL DROP BECAUSE OF THIS SURPLUS.
If the market price is lower than equilibrium price,  $6,
for example,  P=4, Qs=10, and Qd=30.
Since Qs<Qd, There are excess quanitty demanded in the
market. Market is not clear. Market is in shortage.
THE PRICE WILL RISE DUE TO THIS SHORTAGE.