曼昆.经济学原理7-9.ppt

南昌工程学院 邱家海 * When the tax is small (namely, equal to T), the shaded yellow rectangle represents tax revenue. When the tax equals 2T, the pink shaded box represents revenue. The pink shaded box is larger than the yellow box. * The material on cost, producer surplus, and the supply curve is analogous to the material earlier on WTP, consumer surplus, and the demand curve. Therefore, this section provides a bit less detail and should move a little more quickly. * Your students should be able to figure out how to get the Qs numbers in the second column of the table. * The derivation of the staircase-supply curve is analogous to that of the staircase demand curve in the earlier example. Hence, the animation is not as detailed. * For your students’ future reference, you might also note that we can use the term “marginal cost” as short-hand for “cost of the marginal seller.” * It might help to say “participating in the market” means buying and selling. It might also help to say that CS measures the net benefit to buyers: the value they get from the good is the gross benefit, minus what they pay leaves the net benefit, or CS. Similarly, PS is the net benefit to sellers. I did not put “net benefit” on this slide because it is not in the book. But if you wish, you may add it. After showing this slide in class, I show my students a short scene from the movie “Pretty Woman” as an example of these concepts. In this scene, Julia Roberts is taking a bubble bath in Richard Gere’s hotel room (don’t worry – there’s no nudity!). Gere comes into the bathroom and they negotiate a price for her to “be at his beck and call” for one week. After bargaining for a few seconds, they agree on a price of $3000. A minute later, he says he would have paid $4000 (his willingness to pay), and she says she would have accepted $2000 (her “cost”). From this, we can deduce that CS = $1000, PS = $1000, and total surplus = $2000. If this transaction did not occur, then thes