第13章生产成本 - 上海杉达学院.ppt

* * Thinking at the margin helps not only Jack, but all managers in the real world, who make business decisions every day by comparing marginal costs with marginal benefits. * * In the next chapter, we will learn more about how firms choose Q to maximize their profits. * * If you did Active Learning 1 and created a class-generated list of General Motors’ costs, you might return to that list and ask students which of the costs on their list are fixed and which are variable. * * Point out that the TC curve is parallel to the VC curve but is higher by the amount FC. * * Most students quickly grasp the following example. Suppose FC = $1 million for a factory that produces cars. If the firm produces Q = 1 car, then AFC = $1 million. If the firm produces 2 cars, AFC = $500,000. If the firm produces 5 cars, AFC = $200,000. If the firm produces 100 cars, AFC = $10,000. The more cars produced at the factory, the smaller is the cost of the factory per car. * * Many students have heard the terms “cost per unit” or “unit cost” in other business courses. ATC means the same thing. * * In this example, the efficient scale is Q=5, where ATC = $76. At any Q below or above 5, ATC $76. * * The textbook gives a nice analogy to help students understand this. A student’s GPA is like ATC. The grade she earns in her next course is like MC. If her next grade (MC) is less than her GPA (ATC), then her GPA will fall. If her next grade (MC) is greater than her GPA (ATC), then her GPA will rise. I suggest letting students read the GPA example in the book and giving them the following example in class: You run a pizza joint. You’re producing 100 pizzas per night, and your cost per pizza (ATC) is $3. The cost of producing one more pizza (MC) is $2. If you produce this pizza, what happens to ATC? Most students will understand immediately that ATC falls (albeit by a small amount). Instead, suppose the cost of producing one more pizza (MC) is $4. Then,