John Maynard Keynes (a famous British economist) said, “In the long run we are all dead.” An important message in this chapter is, to paraphrase Keynes, “In the long run, all profits in a monopolistically competitive market are dead.” Why do firms in a monopolistically competitive industry earn zero profits in the long run? Why might those same firms earn profits in the short run? Why does a monopolist earn profits in both the long run and the short run?