Problem: In 2008, 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 box (in dollars per box0 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.
1) What was the equilibrium price of a box? Is this the long-run equilibrium price?
2) How many firms are in this industry when it is in long-run equilibrium?