消费者、生产者与市场效率(3).pptVIP

* The area of any rectangle equals base times height. For the green rectangle on this slide, base = 1 height = $300 – 260 = $40 area = 1 x $40 = $40 * The entire green area (total CS) can be divided into two rectangles: The first (and leftmost) represents Flea’s CS. It has a height of $80 and a width of 1. The second represents Anthony’s CS. It has a height of $30 and a width of 1. The sum of these two rectangular areas equals total CS. * The text in the yellow box summarizes the lesson of the two preceding slides. * In “normal” or edit mode, the text appears to overlap with the vertical axis label. Don’t worry – in “Slide Show” or presentation mode, the axis labels disappear before the text appears. * Some students mistake the upper vertical intercept ($60 in this example) for the height of the blue triangle: they forget to subtract off the height of the bottom of the triangle from the height of the top of the triangle. So, the first one or two times, it might be worthwhile to show them how to find the height of the triangle. * The book shows how a lower price increases CS. * 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, mi