<u>Solution and Explanation:</u>
(a). Firm in perfect competition produces at minimum efficient scale, MEC where average cost AC is minimum. The price is determined by the market supply and demand.
(b) Note that q1 is at the minimum of AC while Q* is to the left of q1. Similarly, P1 is equal to MC while P* is higher than MC. This shows that firms in perfect competition produce more and charge less than the firms in monopolistically competitive market.
(c) All firms in monopolistically competitive market as well as perfectly competitive market earn zero economic profit in the long run. This is because there is a free entry and exit
(d) Demand is steeper for firms in monopolistically competitive market so that demand is elastic. Demand is horizontal for any quantity which means it is perfectly elastic for a firm in competitive market.
