Suppose that the market for haircuts in a community is a perfectly competitive constant-cost industry and that the market is initially in long-run equilibrium. Subsequently, an increase in population increases the demand for haircuts. In the long run, we expect that: Question 7 options: a) firms will leave the market, driving the price of haircuts up and the profits of individual firms up. b) more firms will enter the market, driving the price of haircuts up and the profits of individual firms back down to zero. c) firms will leave the market, driving the price of haircuts up and the profits of individual firms back down to zero. d) more firms will enter the market, driving the price of haircuts down and the profits of individual firms back down to zero.

In the case when the demand is increased, the price of haircuts would also increased and due to this the firm could earn positive economic profit. And for earning the economic profit in a positive way, the no of firm should be rised that increased the supply so automatically the prices are decreasing

Therefore the above option should be the answer