The market system is a decentralized decision-making system,the main body of the market has comprehensive decision-making power.Under this system, the main body such as governments at all levers often need to make various kinds of decisions.Information is a sort of resource, which forms the foundation of decision-making,therefore the main body must rely on information.However foil and effective information is not always available for decision-makers,lack of adequate and effective information is referred to ...