What Is the Question of the Chapter? Suppose we observe a collection of a consumer’s choices, can we discover his/her preference? Is this possible at all? If so, under what conditions is this possible? (This is the reverse question of finding the optimal choice)

Where Are We in the Course? We are studying the 1st of the three blocks of microeconomics: Consumer behavior, production theory, and market equilibrium Within the 1st block, we are working on the 2nd of the three components: choice set, preference, and consumer demand

Where are We in the Course? We are working on the 1st of the 3 components of microeconomics: Consumer behavior, production theory, and market. There are three elements of consumer behavior: budget constraint, preference, and choices

Market Equilibrium A market is in equilibrium when total quantity demanded by buyers equals total quantity supplied by sellers

Monetary Measures of Gains-to￾Trade You can buy as much rice as you wish at RMB1 per kilogram once you enter the gasoline market. Q: What is the most you would pay to enter the market?

What Are We Doing in this Chapter? We apply our basic framework of consumer choice to study issues of choices across different time periods; Again, in terms of theoretical framework, not much is new!

How Should a Monopoly Price? So far a monopoly has been thought of as a firm which has to sell its product at the same price to every customer. This is uniform pricing. Can price-discrimination-(差别定价 ) earn monopoly higher profits?

Structure From Individual to Market Demand Functions Elasticities Revenue and ownprice- elasticity of demand Marginal revenue and price elasticity

Structure The cost minimization problem Average costs Returns to scale and total and average costs Short run and long run costs

Structure Utility function(效用函数) Definition Monotonic transformation(单调转换) Examples of utility functions and their indifference curves Marginal utility(边际效用) Marginal rate of substitution边际替代率 MRS after monotonic transformation