Of this form, the suppliers are made use to vender, the made use consumers to buy and it offers if it equals to the demand for one determined price. In few words this is the base of all the Economic Theory. Let us examine the example of the Bar Tavern that produces its proper chope? the Mimus. It imagines that you are one () drinking () of chope of the Skol, but the Tavern is charging a special price of R$ 1,50 for caneco of Mimus. The owner of the bar possesss ten (10) barrels in supply, but it finds that he had himself that to charge the price habitual of 2,80 R$ caneco, perhaps alone obtained to vender one two barrels. You like Skol, but for R$ 1,50 she decides to try the mark cheapest. Here, in this bar, ' ' hand invisvel' ' of the economy it is in action, therefore to the certain price, it has a demand for the ten barrels. Structures of Market In a competitive market exist forces that act moving offer, the demand and the proper prices.

Therefore, how much bigger it will be the competition in one determined market, more sensible it is the market price, in relation to the changes in it offers and the demand. Therefore, we will see below, three types of market structures: pure qMonoplio: it is characterized for to have only one salesman of definitive product (or service) without similars in the market. Example: company LIGHT in the city of the R.J withholds the monopoly of the supply of the electric energy and the TELEMAR, withholds the monopoly of the exploration of the fixed service of telephony in the State of the qOligoplio RIO DE JANEIRO: It is characterized for having one few suppliers of one determined product (or service), for which few substitutes or similars exist. If the sector will be competitive, the monopoly is beneficial for the consumer. (Example: the sector of mobile telephony in Brazil, where exists only four suppliers? Living creature, Clearly, TIM and Oi? he is beneficial for the consumers, therefore the sector of mobile telephony is in frank growth. But, if the sector will not be competitive, the consumers does not have no benefit. (Example: the sector of airlines, where the four participants? Varig, Tam, Goal and BRA? they do not compete between itself e, consequently, the consumers do not have no advantage. qConcorrncia: It is characterized for to have many competitors vendendo one definitive product (or service) with many similars, which can easily be substituted. E, in this in case that, the competition favors the consumers, with products of quality and lesser prices each time. (Example: the Extract sector of Tomatoes, Xampus, Mass, Biscuits, etc.) Therefore, when the Manager will be thinking about the specific conditions of the market of one determined branch or about the individual behavior of the consumers, is in this aspect of the Macroeconomic Theory who it must be intent, a time that the industries produce the amounts that take care of to the demand, to a price of balance based on the structure of the competitive market.