ch4供给与需求的市场力量.md

ch4 供给与需求的市场力量

The Market Forces of Supply and Demand

市场与竞争

• 市场：某种物品或劳务的一群买者与卖者。 A market is a group of buyers and sellers of a particular product.

• 竞争市场：有许多买者与卖者，以至于每个人对市场价格的影响都微乎其微的市场。 A competitive market is one with many buyers and sellers, each has a negligible effect on price

需求

• 物品的需求量： 是买者愿意并且能够购买的一种物品的数量。 The quantity demanded of any good is the amount of the good that buyers are willing and able to purchase.

• 需求表： 表示一种物品的价格与需求量之间关系的表格。 Demand schedule:a table that shows the relationship between the price of a good and the quantity demanded

• 需求曲线 demand curve: a graph of the relationship between the price of a good and the quantity demanded

• 市场需求量是所有买者在每一价格水平下需求量的总和。 The quantity demanded in the market is the sum of the quantities demanded by all buyers at each price.

• 正常物品：在其他条件相同时，收入增加引起需求量增加的物品。 normal good：a good for which, other things equal, an increase in income leads to an increase in demand

• 低档物品：在其他条件相同时，收入增加引起需求量减少的物品。 inferior good： a good for which, other things equal, an increase in income leads to a decrease in demand

• 替代品：一种物品价格上升引起另一种物品需求量增加的两种物品。 Substitutes： two goods for which an increase in the price of one leads to an increase in the demand for the other

• 互补品：一种物品价格上升引起另一种物品需求量减少的两种物品。 Complements：two goods for which an increase in the price of one leads to a decrease in the demand for the other

供给

• 供给量：卖者愿意并且能够出售的一种物品的数量。 quantity supplied： the amount of a good that sellers are willing and able to sell

• 供给表：表示一种物品的价格与供给量之间关系的表格。 supply schedule：a table that shows the relationship between the price of a good and the quantity supplied

• 供给曲线： supply curve：a graph of the relationship between the price of a good and the quantity supplied

• 市场供给量是在每种价格水平下所有卖者的供给量之和。 The quantity supplied in the market is the sum of the quantities supplied by all sellers at each price.

均衡

• 均衡价格：使供给与需求平衡的价格 Equilibrium price: the price that equates quantity supplied with quantity demanded

• 均衡数量：均衡价格下的供给量与需求量 Equilibrium quantity: the quantity supplied and quantity demanded at the equilibrium price

• 过剩 (超额供给):供给量大于需求量的状态 Surplus (a.k.a. excess supply): when quantity supplied is greater than quantity demanded

• 短缺（超额需求）:需求量大于供给量的状态 Shortage (a.k.a. excess demand): when quantity demanded is greater than quantity supplied

• 需求定理：认为在其他条件不变时，一种物品的价格上升，该物品的需求量会减少的观点。 Law of demand: the claim that the quantity demanded of a good falls when the price of the good rises, other things equal

• 供给定理：认为在其他条件不变时，一种物品价格上升，该物品供给量增加的观点。 Law of supply: the claim that the quantity supplied of a good rises when the price of the good rises, other things equal