Unless a monopoly is allowed to exist due to a government license or protection from a strong patent, markets have at least a few sellers. When a market has multiple sellers, at least some of which pr...Unless a monopoly is allowed to exist due to a government license or protection from a strong patent, markets have at least a few sellers. When a market has multiple sellers, at least some of which provide a significant portion of sales and recognize (like the monopolist) that their decisions on output volume will have an effect on market price, the arrangement is called an oligopoly.
