All men have the stars, but they are not the same things for different people. For some, who are travelers, the stars are guides. For others they are no more than little lights in the sky. For others, who are scholars, they are problems. For my businessman they were wealth.

二手车市场是信息不对称的经典例子。

经济研究应旨在为现实世界的决策提供信息。