In 2012, the box industry was perfectly competitive. The lowest point on the long- run average cost curve of each of the identical box producers was $4, and this minimum point occurred at an output of 1,000 boxes per month. The market demand curve for boxes was
QD = 140,000 - 10,000P
where P was the price of a box (in dollars per box) and QD was the quantity of boxes demanded per month. The market supply curve for boxes was
QS = 80,000 + 5,000P
where QS was the quantity of boxes supplied per month.
a. What was the equilibrium price of a box? Is this the long- run equilibrium price?
b. How many firms are in this industry when it is in long- run equilibrium?