Utility
Definition
与人类欲望满足有因果关系的物，我们叫做有用物。 效用是指对于消费者对各种商品和服务的消费或投资的相对满意度的度量。对于投资而言， 是指投资者从不同的投资组合中获得的满意度。基于理性选择理论的经济学理论通常认为 消费者会尽可能最大化其效用。边际效用会随着商品或服务的供应增加而减少，称为边际 效用递减原理。
Within economics, the concept of utility is used to model worth or Value. Its usage has evolved significantly over time. The term was introduced initially as a measure of pleasure or happiness within the theory of Utilitarianism by moral philosophers such as Jeremy Bentham and John Stuart Mill. The term has been adapted and reapplied within neoclassical economics, which dominates modern economic theory, as a utility function that represents a consumer’s preference ordering over a choice set. Utility has thus become a more abstract concept that is not necessarily solely based on the happiness or pleasure received.