消费者剩余 / Consumer surplus

「释义」

消费者剩余是指消费者消费一定数量的某种商品愿意支付的最高价格与这些商品的实际市场价格之间的差额。消费者剩余衡量了买者自己感觉到所获得的额外利益。

马歇尔从边际效用价值论演绎出消费者剩余的概念。消费者剩余是衡量消费者福利的重要指标。产业的社会福利等于消费者剩余加上生产者剩余之和。

「应用场景」

GDP通常作为衡量经济的指标，无论经济增长还是萎缩，GDP都是每季度相对准确的指标。然而，GDP捕捉的仅是经济中所有最终产品的货币价格。因为它衡量的仅仅是我们付出多少，而不是我们受益多少，所以消费者的经济福利可能与GDP并无关联。实际上，有时GDP上升，消费者福利反而下降，反之亦然。

GDP is often used as a proxy for how the economy is doing. It’s a relatively precise number that signals every quarter whether the economy is growing or shrinking. However, GDP captures only the monetary value of all final goods produced in the economy. Because it measures only how much we pay for things, not how much we benefit, consumer’s economic well-being may not be correlated with GDP. In fact, it sometimes falls when GDP goes up, and vice versa.

好消息是，至少从理论上看，依然有办法衡量经济上的消费者福利。这种方法被称为消费者剩余，即消费者愿意为某产品或服务支付的最高价格，与产品服务实际销售价格之差。如果你最多愿意付100美元购买一件衬衫，但只花了40美元，你的消费者剩余就是60美元。

The good news is that economics does provide a way, at least in theory, to measure consumer well-being. That measure is called consumer surplus, which is the difference between the maximum a consumer would be willing to pay for a good or service and its price. If you would have spent as much as $100 for a shirt but paid only $40, then you have a $60 consumer surplus.

以上文字选自《哈佛商业评论》中文版2019年12月刊《如何衡量数字经济？》

埃里克·布莱恩约弗森（Erik Brynjolfsson）阿维纳什·克里斯（Avinash Collis）丨文

马冰仑 丨编辑