微观经济 第3章_需求与供给.ppt

* * * * * * * * * The magic of 市场均衡 and the forces that bring it about and keep the market there need to be demonstrated with the basic diagram, with intuition, and, if you’ve got the time, with hard evidence in the form of further class activity. You might want to begin with the demand curve experiment and explain that in that market, the supply was fixed (vertical supply curve) at the quantity of bottles that you brought to class. The equilibrium occurred where the market demand curve (demand by the students) intersected your supply curve. Then you might use the supply curve experiment and explain that in that market, demand was fixed (vertical demand curve) at the quantity that you had decided to buy. The equilibrium occurred where the market supply curve (supply by the students) intersected your demand curve. Point out that the trades you made in your little economy made buyers and sellers better off. If you want to devote a class to equilibrium and the gains from trade in a market, you might want to run a double oral auction. There are lots of descriptions of these and one of the best is at Marcelo Clerici-Arias’s Web site at Stanford University—/~marcelo/index.html?Teaching/Docs/Experiments/Auction/auction.htm~mainFrame * * * * The whole chapter builds up to this section, which now brings all the elements of demand, supply, and equilibrium together to make predictions. Students are remarkably ready to guess the consequences of some event that changes either demand or supply or both. They must be encouraged to work out the answer and draw the diagram. Explain that the way to answer any question that seeks a prediction about the effects of some events on a market has five steps. Walk them through the steps and have one or two students work some examples in front of the class. The five steps are: 1.Draw a demand-supply diagram and label the axes with the price and quantity of the good or service in question. 2. Think about the events that you are told occur and d