关系是用来平衡的

People face tradeoffs

The first lesson about making decisions is summarized in the adage，“there is no such thing as a free lunch.”To get one thing that we like，we usually have to give up another thing that we like.Making decisions requires trading off one goal against another．

Consider a student who must decide how to allocate her most valuable resource—her time.She can spend all of her time studying economics; she can spend all of her time studying psychology; or she can divide her time between the two fields.For every hour she studies one subject，she gives up an hour that she could have spent napping，bike riding，watching TV，working at her part-time job for some extra spending money．

When people are grouped into societies，they face different kinds of tradeoffs．

The classic tradeoff is between“guns and butter.”The more we spend on national defense to protect our shores from foreign aggressors ( guns) ，the less we can spend on consumer goods to raise our standard of living at home ( butter) .Also important in modern society is the tradeoff between a clean environment and a high level of income.Laws that require firms to reduce pollution raise the cost of producing goods and services.Because of the higher costs，these firms end up earing smaller profits，paying lower wages，charging higher prices，or some combination of these three．

Thus，while pollution regulations give us the benefit of a cleaner environment and the improved health that comes with it，they have the cost of reducing the incomes of the firms'owners，workers，and customers．

Another tradeoff society faces is between efficiency and equity.Efficiency means that society is getting the most it can from its scarce resources.Equity means that the benefits of those resources are distributed fairly among society's members.In other words，efficiency refers to the size of the economic pie，and equity refers to how the pie is divided.Often，when government policies are being designed，these two goals conflict．

Recognizing that people face tradeoffs does not by itself tell us what decisions we will or should make.A student should not abandon the study of psychology just because doing so would increase the time available for the study of economics.Society should not stop protecting the environment just because environmental regulations reduces our material standard of living.The poor should not be ignored just because helping them distorts work incentives.Nonetheless，acknowledging life's tradeoffs is important because people are likely to make good decisions only if they understand the options that have available．

人们面临权衡取舍关系

关于作出决策的第一课可以归纳为一句谚语: “天下没有免费的午餐”。为了得到我们喜爱的一件东西，通常就不得不放弃另一件我们喜爱的东西。作出一个决策，要求我们权衡取舍，即在一个目标与另一个目标之间有所取舍。考虑一下一个学生如何决定配置她最宝贵的资源——时间。她可以把所有的时间用于学习经济学; 可以把所有的时间用来学习心理学; 也可以把时间适当分配在这两个学科上。她把某一个小时用于学习一门课时，她就必须放弃本来可以学习另一门课的一个小时。而且，对于她用于学习一门课的每一个小时，她要放弃本来可以用于睡眠、骑车、看电视或打工赚点零花钱的时间。

当人们组成社会时，他们面临各种不同的权衡关系。典型的就是“大炮与黄油”之间的权衡。我们把更多的钱用于国防以保卫我们的海岸免受外国的入侵( 大炮) 时，我们能用于提高国内生活水平的个人物品的消费( 黄油) 就少了。

在现代社会里，同样重要的是清洁的环境和高收入水平之间的权衡关系。要求企业减少污染的法律增加了生产物品与劳务的成本。由于成本高，结果这些企业赚的利润少了，支付的工资低了，收取的价格高了，或者是这三种结果的某种结合，因此尽管污染管制给予我们的好处是更清洁的环境以及由此引起的健

康的改善，但其代价是企业所有者、工人和消费者的收入减少。

社会面临的另一种权衡关系是效率与平等之间的权衡。效率是指社会能从其稀缺资源中得到最多的东西。平等是指这些资源的成果公平地分配给社会成员。换句话说，效率是指经济蛋糕的大小，而平等是指如何分割这块蛋糕，在设计政府政策的时候，这两个目标往往是不一致的。

认识到人们面临权衡关系本身并没有告诉我们，人们将会或应该作出什么决策。一个学生不应该仅仅由于要增加用于学习经济学的时间而放弃心理学的学习，社会不应该仅仅由于环境控制降低了我们的物质水平而不再保护环境，也不应该仅仅由于帮助穷人扭曲了工作激励机制而忽视了他们。然而，认识到生活中的权衡关系是重要的，因为人们只有了解了他们可以得到的选择，才能作出良好的决策。