1. What are the four main reasons monopolies arise?

2. How a monopoly chooses price and output?

3. A newspaper article has the headline "Google Says It's Actually Quite Small." According to the article: Google rejects the idea that it's in the search advertising business, an industry in which it holds more than a 70 percent share of revenue. Instead, the company says its competition is all advertising, a category broad enough to include newspaper, radio and highway billboards. Why does Google care whether people think it is large or small? Do highway billboards actually provide competition for Google? Briefly explain. Source: Jeff Horwitz, "Google Says It's Actually Quite Small," Washington Post, June 7, 2009.