Lecture 2 Demand & Supply

Demand 需求

Willingness and ability of consumers to buy a product at different prices. 消费者在不同价格下愿意并且有能力购买商品。

Law of Demand 需求定律

As price rises, quantity demanded falls. As price falls, quantity demanded rises. 价格上升，需求量下降；价格下降，需求量上升。

Quantity Demanded 需求量

Amount consumers are willing and able to buy. 消费者愿意并有能力购买的数量。

Income Effect 收入效应

Higher prices make consumers feel poorer. 价格上涨会让消费者感觉自己变穷。

Substitution Effect 替代效应

Consumers switch to cheaper alternatives. 消费者会转向较便宜的替代品。

Demand Curve 需求曲线

Shows the relationship between price and quantity demanded. 显示价格与需求量之间的关系。

Change in Quantity Demanded 需求量变动

Caused ONLY by a change in price. 只因价格改变而发生。

Movement Along Demand Curve 沿着需求曲线移动

Occurs when price changes. 当价格改变时发生。

Change in Demand 需求变动

Caused by factors other than price. 由价格以外的因素引起。

Shift of Demand Curve 需求曲线移动

Entire demand curve shifts left or right. 整条需求曲线向左或向右移动。

Determinants of Demand 需求决定因素

Income, tastes, population and prices of related goods. 收入、喜好、人口及相关商品价格。

Substitute Goods 替代品

Goods that can replace each other. 可以互相替代的商品。

Substitute Goods Example 替代品例子

Coffee and tea. 咖啡和茶。

Complementary Goods 互补品

Goods that are used together. 必须一起使用的商品。

Complementary Goods Example 互补品例子

Cars and petrol. 汽车和汽油。

Normal Goods 正常商品

Demand increases when income increases. 收入增加，需求增加。

Inferior Goods 劣等商品

Demand decreases when income increases. 收入增加，需求减少。

Supply 供给

Willingness and ability of producers to sell a product at different prices. 生产者在不同价格下愿意并且有能力出售商品。

Law of Supply 供给定律

As price rises, quantity supplied rises. As price falls, quantity supplied falls. 价格上升，供给量增加；价格下降，供给量减少。

Quantity Supplied 供给量

Amount producers are willing and able to sell. 生产者愿意并有能力出售的数量。

Supply Curve 供给曲线

Shows the relationship between price and quantity supplied. 显示价格与供给量之间的关系。

Change in Quantity Supplied 供给量变动

Caused ONLY by a change in price. 只因价格改变而发生。

Movement Along Supply Curve 沿着供给曲线移动

Occurs when price changes. 当价格改变时发生。

Change in Supply 供给变动

Caused by factors other than price. 由价格以外的因素引起。

Shift of Supply Curve 供给曲线移动

Entire supply curve shifts left or right. 整条供给曲线向左或向右移动。

Determinants of Supply 供给决定因素

Production costs, technology, government policies and number of firms. 生产成本、科技、政府政策及厂商数量。

Market Equilibrium 市场均衡

Occurs when quantity demanded equals quantity supplied. 当需求量等于供给量时发生。

Equilibrium Price 均衡价格

Price at market equilibrium. 市场均衡时的价格。

Equilibrium Quantity 均衡数量

Quantity at market equilibrium. 市场均衡时的数量。

Shortage 短缺

Quantity demanded exceeds quantity supplied. 需求量大于供给量。

Effect of Shortage 短缺影响

Prices rise. 价格会上涨。

Surplus 过剩

Quantity supplied exceeds quantity demanded. 供给量大于需求量。

Effect of Surplus 过剩影响

Prices fall. 价格会下降。

Price as Rationing Mechanism 价格配给机制

Prices help allocate scarce resources. 价格帮助分配有限资源。

Increase in Demand 需求增加

Causes shortage and pushes prices up. 导致短缺并推动价格上涨。

Increase in Supply 供给增加

Causes surplus and pushes prices down. 导致过剩并推动价格下降。

Price Ceiling 最高限价

Maximum legal price set below equilibrium price. 政府规定低于均衡价格的最高售价。

Effect of Price Ceiling 最高限价影响

Creates shortages. 造成市场短缺。

Price Floor 最低限价

Minimum legal price set above equilibrium price. 政府规定高于均衡价格的最低售价。

Effect of Price Floor 最低限价影响

Creates surpluses. 造成市场过剩。