Problem
Canada Post has a monopoly on residential mail delivery. Pfizer Inc. makes Lipitor, a prescription drug that lowers cholesterol. Rogers Communications is the sole provider of cable television service in some parts of Ontario. Are any these firms protected by a barrier to entry? Do any of these firms produce a good or service that has a substitute? Might any of them be able to profit from price discrimination? Explain your answers.
The response should include a reference list. Double-space, using Times New Roman 12 pnt font, one-inch margins, and APA style of writing and citations.