Are monopolies realistic?

• A true monopoly is rare
  • Defining a market is incredibly difficult
  • Markets with only a single supplier are rare
• Here are a few examples of monopolies
  • AT&T was the only long-distance telecommunications service prior to 1984
  • Cycloserine is the only drug on the market to treat drug-resistant tuberculosis
  • EWEB is the only electricity provider in Eugene
  • Many cities only have a single cable provider