# Principles of Economics
# 经济学的十个原理
- How People Make Decisions?
①. People face tradeoffs.
②. The cost of something is what you give up to get it.
③. Rational people think at the margin.
④. People respond to incentives.
- How People Interact?
⑤. Trade can make everyone better off.
⑥. Markets are usually a good way to organize economic activity.
⑦. Governments can sometimes improve market outcomes.
- How the Economy as a Whole Works?
⑧. The standard of living depends on a country's production.
⑨. Prices rise when the government prints too much money.
⑩. Society faces a short-run tradeoff between inflation and unemployment.
# 经济相互依存性和贸易的好处
什么决定了生产和贸易的模式？ / What determines the pattern of production and trade?
生产和贸易的模式是基于机会成本（opportunity costs）的差异。
（Specialize and Trade）证明：1. 当每个人更多地生产自己具有比较优势的物品时，经济的总产量增加了。 2. 机会成本的差别（即比较优势）为人们从贸易中受益创造了条件。
比较优势原理（The Principle of Comparative Advantage）:每个人各自生产他们具有比较优势的产品、然后进行交易，那么他们的情况都会变好。
绝对优势（Absolute Advantage）:生产商在生产一种产品时的要素投入少，则他在生产该种产品是具有绝对优势。
# 供给与需求（Supply and Demand）
Supply and demand are the forces that make market economies work.
Modern microeconomics is about supply, demand, and market equilibrium.
分析竞争市场分为三步：※ 需求模型 Demand ※ 供给模型 Supply ※ 供求均衡模型 Demand and Supply, or Market equilibrium
需求量（Quantity demanded）是买者愿意而且能够(willing and able) 购买的商品数量。
# 市场和政府政策
市场运行的最基本的力量是供给、需求，可以被观察到的是这两条曲线的交点：价格。
政府干预比如价格限制、税收，那么政府干预会导致什么结果？
- 在自由的、无管制的市场中，市场的力量是建立均衡价格，决定交换的数量。（Tn a free, unregulated market system, market forces establish equilibrium prices and exchange quantities.）
- 虽然均衡的状态是有效率的，但也许并非使每人都满意。（While equilibrium conditions may be efficient, it may be true that not everyone is satisfied.）
- 经济学家的作用之一是运用他们的理论帮助指定政府政策（One of the roles of economies is to use their theories to assist in the development of policies.）
# 价格控制 Price Controls
- 实行价格控制通常是政府相信市场价格对买房或卖方不公平（Are usually enacted when policymakers believe the market price is unfair to buyers or sellers.）
- 两种价格控制：价格上限和价格下限（Result in government-created price ceilings and floors.）
- 常常引发事与愿违的结果（效率和公平损失）
- 经济分析的重要性：供给和需求工具
