1.1 Introduction to macroeconomics

Introduction to economics

Excerpts From An Inquiry into the Nature and Causes of the Wealth of Nations, Book IV, Chap. 2
by Adam Smith. London: Methuen and Co., Ltd., 1904. Edwin Cannan, ed. First published 1776.

But the annual revenue of every society is always precisely equal to the exchangeable value of the whole annual produce of its industry, or rather is precisely the same thing with that exchangeable value. As every individual, therefore, endeavours as much as he can both to employ his capital in the support of domestic industry, and so to direct that industry that its produce may be of the greatest value; every individual necessarily labours to render the annual revenue of the society as great as he can.

He generally, indeed, neither intends to promote the public interest, nor knows how much he is promoting it. By preferring the support of domestic to that of foreign industry, he intends only his own security; and by directing that industry in such a manner as its produce may be of the greatest value, he intends only his own gain, and he is in this, as in many other cases, led by an invisible hand to promote an end which was no part of his intention. Nor is it always the worse for the society that it was no part of it. By pursuing his own interest he frequently promotes that of the society more effectually than when he really intends to promote it.

I have never known much good done by those who affected to trade for the public good. It is an affectation, indeed, not very common among merchants, and very few words need be employed in dissuading them from it. [Par. IV.2.9]

“ 社会的年收入，总是等于全部年产物的交换价值，甚至可以说，它们其实是同一个东西。 所以，当商人们都尽力将其资本投在国内产业上，并通过细心管理来使生产物达到最高的交换价值时，社会的年收入自然会随之增加。

商人们的初衷，的确不是增加公共利益。所以，就连他自己在客观上增加了公共利益，他也不知道。 他所考虑的，只是自己的安全，所以他宁愿将资本投在国内产业上，也不支持国外产业。 还是出于自身利益的考虑，他采取了可能使其生产物达到最高交换价值的管理方式。 他在自身利益这只看不见的手的指导之下，为达到一个并非他本意想要达到的目的而努力着。 不过，虽然商人的行为不是出于本意，但也不能因此就说这一行为对社会有害。虽然商人的本意是追求自身利益， 但他在追求自身利益的过程中，却为社会带来了更多的利益。

有些人虽说是为公众幸福才从事商业的，但我从未听说他们做了什么好事。 幸好这种装腔作势的商人并不多见，所以我们也用不着理会他们。 ”

"An economist is a man who states the obvious in terms of the incomprehensible."
- Alfred A. Knopf

“经济学家是用难以理解的方式陈述显而易见的事物的人。”

"An economist is an expert know will know tomorrow why the things he predicted yesterday didn't happen today."
- Laurence J. Peter

“经济学家是一个明天就会知道为什么他昨天预测的事情今天没有发生的专家。”

Scarcity

The entire field of economics is based on the idea of scarcity.

整个经济学领域都是基于“稀缺”这一概念。

And, arguably, we wouldn't even need a field of economics, if there wasn't the notion of scarcity in the world.

可以说，如果世界上没有稀缺性的概念，我们甚至不需要经济学这个学科。

And the reason why scarcity is essential to economics is because economics is the study of how do you allocate these scarce resources.

稀缺性之所以对经济学至关重要，是因为经济学是研究如何分配这些稀缺资源的学科。

Air for most of human history has been considered a free resource. And even today I'd argue that something like oxygen, at least on our planet, is considered a free resource.

When I take a deep breath it does not affect your ability to take a deep breath. It does not take oxygen away from you.

Now is there an infinite amount of oxygen in our atmosphere? No. But for our purposes it feels like there's an infinite amount.

Now if the photosynthetic plants were to disappear and all of a sudden oxygen started to get diminished, or if we were in a space station where there isn't a seemingly infinite amount of oxygen, well then you could imagine a world where it could become a scarce resource.

如果光合作用植物消失，氧气一下子开始减少，或者如果我们在一个空间站里，那里没有看似无限的氧气，那么你可以想象一个氧气可能成为稀缺资源的世界。

You can imagine a colony on the Moon or on Mars or in the space station where it had some type of economic system to decide who gets how much oxygen.

你可以想象月球、火星或空间站上的一个殖民地，那里有某种经济系统来决定谁获得多少氧气。

◎ 关于个人做出决策的基本结论是：人们面临不同目标之间的权衡取舍；任何一种行为的成本可以用其所放弃的机会来衡量；理性人通过比较边际成本与边际收益做出决策；人们根据他们所面临的激励改变自己的行为。

◎ 关于人们之间相互影响的基本结论是：贸易和相互依赖性可以是互利的；市场通常是协调人们之间经济活动的一种好方法；通过纠正市场失灵或者提高经济中的平等程度，政府可能改善市场结果。

◎ 关于整体经济的基本结论是：生产率是生活水平的最终根源；货币量的增长是通货膨胀的最终根源；社会面临通货膨胀与失业之间的短期权衡取舍。

1. 稀缺性：社会资源的有限性。
2. 经济学：研究社会如何管理自己的稀缺资源。
3. 效率：社会能从其稀缺资源中得到最大利益的特性。
4. 平等：经济成果在社会成员中平均分配的特性。
5. 机会成本：为了得到某种东西所必须放弃的东西。
6. 理性人：系统而有目的地尽最大努力实现其目标的人。
7. 边际变动：对行动计划的微小增量调整。
8. 激励：引起一个人做出某种行为的某种东西。
9. 市场经济：当许多企业和家庭在物品与服务市场上相互交易时，通过他们的分散决策配置资源的经济。
10. 产权：个人拥有并控制稀缺资源的能力。
11. 市场失灵：市场本身不能有效配置资源的情况。
12. 外部性：一个人的行为对旁观者福利的影响。
13. 市场势力：单个经济活动者（或某个经济活动小群体）对市场价格有显著影响的能力。
14. 生产率：每单位劳动投入所生产的物品与服务数量。
15. 通货膨胀：经济中物价总水平的上升。
16. 经济周期：就业和生产等经济活动的波动。

Normative and positive statements

A positive statement is something that, it doesn't necessarily have to be true but it's something that can be tested.

实证表述[5]（positive statements）是关于世界是什么的论断。

A normative statement is one that really is a matter of opinion, maybe a matter of ethics, something that someone thinks is how the world should be.

规范表述[6]（normative statements）是关于世界应该是什么的论断。当经济学家做出规范表述时，他们的行为更像是政策顾问而不是科学家。

1. 循环流量图：一个说明货币如何通过市场在家庭与企业之间流动的直观经济模型。
2. 生产可能性边界：表示在可得到的生产要素与生产技术既定时，一个经济所能生产的产品数量的各种组合的图形。
3. 微观经济学：研究家庭和企业如何做出决策，以及它们如何在市场上相互交易的学科。
4. 宏观经济学：研究整体经济现象，包括通货膨胀、失业和经济增长的学科。
5. 实证表述：试图描述世界是什么样子的观点。
6. 规范表述：试图描述世界应该是什么样子的观点。

Economic models

Command and market economies

So on one side, you have what's known as a command economy and good examples of command economies are the communist states, especially during the 20th century, The USSR, the Soviet Union being the best example of that.

一方面是计划经济，计划经济的典范是共产主义国家，尤其是在 20 世纪，苏联就是最好的例子。

In a command economy, the government controls what's often known as the factors of production and sometimes, in an extreme case, there might not even be private ownership.

在计划经济中，政府控制着通常所说的生产要素，有时在极端情况下，甚至可能不存在私有制。

Now the other side of the spectrum, you have what's known as a market economy. And most economies in the world, especially the United States, are much closer to being a market economy than being a command economy.

而另一方面，则是市场经济。世界上大多数经济体，尤其是美国，更接近市场经济而不是指令经济。

Rather than having the government owning the factors of production, deciding who produces what and how much and who gets those things, in a market economy, it's all based on the factory right over here, independent of the government for the most part unless you're in certain fields that might have strong influence from the government, let's say you're a military contractor.

And so there's actually a spectrum between a command economy and a market economy.

With most economies actually falling in this inbetween state which is sometimes referred to as a mixed economy.

For example, as I already mentioned, the United States which is considered a very capitalist country with a market economy, it still does have some public ownership.

例如，正如我已经提到的，美国被认为是一个非常资本主义的市场经济国家，它仍然存在一些公有制

The government still does control certain aspects of the economy, it still represents a fairly large chunk of the economy.

And so a pure command economy government would control everything, pure market economy, you would have very little that's controlled by the government, but the reality in most of the world, things fall in this mixed economy spectrum.

summary

Key Terms

Term	Definition
economics	the study of how individuals and societies choose to allocate scarce resources.
scarcity	the fact that there is a limited amount of resources to satisfy unlimited wants.
ceteris paribus	a Latin phrase meaning "all else equal".
incentives	rewards or punishments associated with a possible action; agents make decisions based on incentives.
rational decision making	an agent is "rational" if they use all available information to choose an action that makes them as well off as possible; economic models assume that agents are rational.
positive analysis	analytical thinking about objective facts and cause-and-effect relationships that are testable, such as how much of a good will be sold when a price changes.
normative analysis	unlike positive analysis, normative analysis is subjective thinking about what we should value or a course of action that should be taken, such as the importance of environmental factors and the approach to managing them.
microeconomics	the study of the interactions of buyers and sellers in the markets for particular goods and services
macroeconomics	the study of aggregates and the overall commercial output and health of nations; includes the analysis of factors such as unemployment, inflation, economic growth and interest rates.