What characteristics make a market into an oligopoly?

Average cost of a can of pop? Something which may be used to create goods or services? What are the advantages of the voluntary sector in the local community? What are the rules and regulation in bowling? What is the size of the US deficit? Will the IRS take money for the 2008 stimulus check received on 2009 tax return? How do you make priorities and what influences your decisions? What will the stock market do tomorrow? What would happen to secondary consumers and producers if primary consumers were removed from an ecosystem? What were the main aims of forming COMESA and what are its benefits? What are advantages of idolatry? What happens to a market in equilibrium when there is an increase in supply? What does The theory of laissez-faire capitalism advocates? What is a 2009 e pluribus unum penny with a cabin on it worth? When people use resources to produce products or provide services that meet certant wants and needs what are they creating? What is Phim Yen Vi known for? What is the meaning of the term offshoring in business? How is opportunity cost rate used in time value analysis? If several firms decide together to set the market price below their costs for the short term to drive competitors out of business what are they participating in? How was Hamilton's economic philosophy similar to his political philosophy?