highest profit margin restaurant business (2) actual income -- the increase of material wealth; Savers can earn more than 40 points from the one-year top bond, compared with the beginning of the year. In January Atom Bank, a mobile phone provider, paid 1.95 PCS for 1.4 PCS. In terms of the purchase of intermediate products in the market, because a lot of manufacturers are generally buy goods from a handful of suppliers, it is beneficial to this a few suppliers to achieve economies of scale and reduce the cost of production. Moreover, market competition pressure between intermediate product suppliers forces suppliers to reduce production costs. In addition, when a few suppliers in the face of many intermediate products of demanders, these a few suppliers can be avoided due to the limited market demand caused by unstable, the loss that may lead to maintain a stable overall sales. If classical economists have interpreted the "market" as "laissez-faire", coase has answered the question of how to achieve "laissez-faire" or "price mechanism".