In the world of economics, the competition between businesses is not always the same or level. Certain fields of industry have very different types of markets than that of others. Where one business could find itself in a field of competition where the playing field is leveled and easy to gain a foothold within, others find themselves in playing fields that are heavily stacked to favor one (or several large) industrial player. The most common forms of market structure that are seen in the economic world are: perfect competition, monopolistic competition, monopoly, and the oligopoly. All of these market structures have defining characteristics that separate them from each other and are all set up in a way that will have a dramatic distinction on how the competition within that market works. The defining characteristics of the market structure will be one of the most important determining factors in how many, as well as, how large the major players An externality occurs whenever the actions of
one party make another party worse or better off, yet the first party neither
bears the costs nor receives the benefits of doing so.