Answer:
A profit-maximizing firm facing economies of scale that is subject to average cost pricing regulation will produce _too little_ from the standpoint of economic efficiency and _not earn_ economic profits.
Step-by-step explanation:
Economies of Scale is the cost advantage that a firm experienced when it increases the level of production output, thereby lowering the cost per unit output. The effect of this is to reduce the average costs of production. This advantage occur due to inverse relationship between per-unit fixed cost and the quantity produced. Firms exploit this advantage to expand their scale of production.
Therefore a profit maximizing firm that is face with economies of scale and subject to average cost pricing regulation will tend to produce less when the cost of production is greater than the revenue, by so doing they earn no economy profit.