Question

How are price and output determined under perfect competition?

Answer 1

Under perfect competition, price and output are determined by the interaction of market demand and supply at the industry level, as firms are price takers and cannot influence the market price individually.

Price Determination:

1. The industry demand curve and supply curve jointly determine the market equilibrium price.
2. The equilibrium price is where the quantity demanded equals the quantity supplied i.e., the point where the demand and supply curves intersect.
3. Individual firms accept this market price as given because products are homogeneous and there are many sellers; no single firm can influence the price.
4. If the price is above equilibrium, excess supply leads sellers to lower the price; if below equilibrium, excess demand pushes the price up until the equilibrium is restored.

Output Determination for the Firm:

1. The firm faces a perfectly elastic (horizontal) demand curve at the market price, meaning it can sell any quantity at that price.
2. To maximize profit, the firm produces the quantity where its marginal cost (MC) equals the market price (which equals marginal revenue MR in perfect competition).
3. In short-run equilibrium, the firm may earn supernormal profits, normal profits, or incur losses, but produces so long as price covers average variable costs.
4. In the long run, firms enter or exit the market, leading to a situation where price equals the minimum point of the long-run average cost (LAC) curve, and firms earn normal profits only.