As we have said before that (Costa) cannot raise the value of the price of products because this is very difficult and may lose consumers in the present of competitors, and the best solution to compete in the possible economic profits can be zero, that Costa (sell) at a lower price, And here the demand will increase and the profit level will. Be good in the expected economic conditions Thus, the short-term cost system can be used during the period of competitive advantage in price or during the decline of profits for companies in the market to zero, and during this period (Costa) will be able to raise the selling rate without any losses by reducing the price to get more consumers. The competitive advantage between companies creates from the