市场需求理论（二） | 武大经济学课

总结于武大经济学课

一：Effects of Price on Quantity Demanded:

• Law of demand需求定律: Other things being equal (ceteris paribus 其他条件[情况]均同，别无其他情形), quantity demanded of one goods changes negatively with the price of the goods.
• Reason of law of demand:
  • Substitution effect
  • Income effect
• Other ways expressing law of demand, in addition to verbal expression 言语表达:
  • Demand Schedule
  • Demand Curve

Fig. 1

• Notes on the Law of Demand
  • Other things being equal (ceteris paribus)
  • Exception: Giffen good and conspicuous consumption

Fig. 2

• Notes on The curve:
  • demand price
  • consumer equilibrium

二：Effect of Non-price Forces on Demand: Shift in Demand Curves

Fig. 3

三：Changes in Quantity and Changes in Demand

• Changes in quantity demanded:
  • caused by a good’s own price changes only
  • movements along a curve
• Changes in demand:
  • caused by other forces than its own price
  • shifts in a curve
• Conclusion: all determinants can be summarized in demand curves