5.2
5.2 边际效用
边际效用
边际效用衡量的是一个人多消费一单位商品所得到的额外满足感。假设妮可(Nicole)非常饿,她点了一份披萨。她吃了第一块,这便给她带来了极大的满足感。这种满足感就是她吃第一块披萨的效用。接下来她又吃了一块披萨。在她吃第二片披萨时所额外得到的满足感就是它的边际效用。
边际效用…
设想一个女孩在烈日下骑着摩托车,感到口渴。
看到一个加油站后,她买了一瓶水。这第一瓶水给她带来了极大的满足感或效用。
仍然口渴,她又拿了一瓶水。
然而,此方法的实用性不如第一种。
如果她饮用更多的瓶装水,可能会产生负效用。
边际效用衡量一个人消费额外一单位商品所带来的额外满足感。
边际效用递减规律指出,在其他条件不变的情况下,当一种商品的消费量达到足够程度后,每增加一单位消费所带来的效用增量将逐渐减少。
以消耗的水量按瓶数进行划分为例。实际上,商品可被划分为数百甚至数千个单位。无论增量多么微小,每增加一个单位的商品所带来的满足感都会减少,从而在图表上形成一条持续递减的曲线。
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Q1: What does marginal utility measure in consumer behavior?
Marginal utility measures the additional satisfaction a person gains from consuming one more unit of a commodity. For example, the first bottle of water provides immense satisfaction to a thirsty person, while the second bottle provides less additional satisfaction. Understanding marginal utility helps explain how consumer satisfaction changes with each additional unit consumed.
Q2: Why does satisfaction decrease with each additional unit consumed?
The law of diminishing marginal utility states that after consuming a sufficient quantity of a commodity, the utility from each successive unit decreases, all other things being equal. As a person consumes more pizza slices, each additional slice provides less satisfaction than the previous one, eventually reaching zero or negative utility.
Q3: How does the relationship between total utility and marginal utility work?
Total utility is the cumulative satisfaction from all units consumed, while marginal utility is the satisfaction from one additional unit. The relationship between total utility and marginal utility shows that as marginal utility decreases, total utility continues to increase but at a slower rate until marginal utility becomes negative.
Q4: Can marginal utility ever become negative?
Yes, marginal utility can become negative when consuming additional units actually decreases overall satisfaction. For instance, after eating many pizza slices, consuming more may cause discomfort, resulting in negative utility. This explains why consumers eventually stop purchasing additional units of a good.
Q5: How does marginal utility apply to real-world consumer decisions?
Consumers use marginal utility concepts when deciding whether to purchase additional units. A motorcycle rider buys water bottles based on the satisfaction each provides. Once marginal utility becomes low or negative, the consumer stops buying, which influences demand patterns and purchasing behavior in markets.
Q6: Does the size of consumption units affect marginal utility?
No, the principle of diminishing marginal utility applies regardless of unit size. Whether goods are divided into large or tiny increments, each additional unit provides less satisfaction than the previous one. This creates a continuous diminishing curve on a graph, illustrating the universal nature of this economic principle.