Explanation : There is no certainty that a monopoly firm will always earn an economic or abnormal profit. Whether a monopoly firm earns an abnormal profit or normal profit or incurs loss depends on (i) its cost and revenue conditions; (ii) threat from potential competitors: and (iii) government policy in respect of monopoly. If a monopoly firm operates at the level of output where MR = MC, its profit depends on the relative levels of AR and AC. Given the level of output, there are three possibilities. (i) if AR > AC, there is abnormal profit for the firm. (ii) if AR = AC, the firm earns only a normal profit, and (iii) if AR < AC, though only a theoretical possibility, the firm makes losses.