Discuss how economic profits for firms in a perfectly competitive industry tend to vanish in the long run? You can explain with the help of graphs. Can a competitive firm increase economic profit using advertisement as a profit maximization strategy in the long run. Discuss how economic profits for firms in a perfectly competitive industry tend to vanish in the long run? You can explain with the help of graphs. Can a competitive firm increase economic profit using advertisement as a profit maximization strategy in the long run. Question 1 What is the profit maximizing level of output and price?.