复习题：

1. Explain how a firm’s production function is related  to its marginal product of labor, how a firm’s marginal product of labor is related to the value
of its marginal product, and how a firm’s value of marginal product is related to its demand for labor. 解释一个企业的生产函数如何与其劳动力的边际产量相关，一个企业的劳动力边际产量如何与其边际产量价值相关，以及一个企业的边际产量价值如何和劳动力需求相关。

答：一个企业的生产函数，描述生产活动中，劳动力的使用量和产品产量之间的关系。劳动力的边际产量是增加一个单位的劳动力，引起的产量增加。这样，劳动力的边际产量直接决定于生产函数。劳动力的边际产量价值，是劳动力的边际产量乘以该产品的市场价格。

     一个竞争性的、利润最大化的企业，增加雇员人数直到劳动力的边际产量价值等于劳动力的工资。其结果，边际产量价值曲线就是劳动力需求曲线。

2. Give two examples of events that could shift the demand for labor.

答：产品价格可以引起劳动力需求曲线移动，技术进步也可以引起劳动力需求曲线移动。

3. Give two examples of events that could shift the supply of labor.

答：劳动者嗜好，可供选择的其它机会以及移民可以引起劳动力供应曲线的移动。

4. Explain how the wage can adjust to balance the supply and demand for labor while simultaneously equaling the value of the marginal product of labor.解释工资如何调节劳动力供需平衡，同时使工资等于劳动力边际产量价值。

答：The wage can adjust to balance the supply and demand for labor while simultaneously equaling the value of the marginal product of labor.  Supply and demand for labor determine the equilibrium wage. 劳动力的供应和需求决定均衡工资。公司通过工资等于劳动力边际产量价值的工人数量，使利润最大化。

5. If the population of the United States suddenly grew because of a large immigration, what would happen to wages? What would happen to the rents earned by the owners of land and capital? 如果因为移民，美国人口猛增，工资如何变化？土地和资本的租金如何变化？

答：A large immigration would increase the supply of labor, thus reducing the wage.  With more labor working with capital and land, the marginal product of capital and land is higher, so rents earned by owners of land and capital would increase.移民增加导致劳动力供应增加，引起工资降低。因为和土地和资本结合的劳动力数量增加，使资本和土地的边际产量增加，土地和资本的租金也将增加。

应用题：

1. Suppose that the president proposes a new law aimed at reducing heath care costs: All Americans are to be required to eat one apple daily.
a. How would this apple-a-day law affect the demand and equilibrium price of apples?

答：引起苹果的需求曲线向右移动，均衡量和均衡价格提高。

b. How would the law affect the marginal product and the value of the marginal product of apple pickers?

答：Since the price of apples increases, the value of marginal product increases for any given quantity of labor.  There is no change in the marginal product of labor for any given quantity of labor.  However, firms will choose to hire more workers and thus the marginal product of labor at the profit-maximizing level of labor will be lower.因为苹果均衡价格提高，不管雇佣多少员工，劳动力的边际产量价值都提高了。但是，劳动力的边际产量却没有改变。公司将雇佣更多员工，公司利润最大化的劳动力边际产量降低了。

c. How would the law affect the demand and equilibrium wage for apple pickers?

答：正像苹果市场一样，劳动力均衡量和均衡价格将提高。这也说明，劳动力需求是派生需求。

2. Henry Ford once said: “It is not the employer who pays wages—he only handles the money. It is the product that pays wages.” Explain. 亨利·福特说过：不是雇主在支付工资，他只是在管理这些钱，而是产品在支付工资。 解释。

答： 用经济学的语言来讲，他是说，劳动力需求是派生需求。工资决定于最终产品的价格和工人的劳动生产率。

3. Show the effect of each of the following events on the market for labor in the computer manufacturing industry.
a. Congress buys personal computers for all American college students.

答：电脑行业雇员增加工资提高。

b. More college students major in engineering and computer science.

答：计算机从业人数增加而工资下降。

c. Computer firms build new manufacturing plants.

答：计算机新工厂的建立，提高了劳动力的边际产量和边际产量价值。增加了工人需求，需求曲线右移，这样工人数量和工资同时增加。

4. Your enterprising uncle opens a sandwich shop that employs 7 people. The employees are paid $6 per hour, and a sandwich sells for $3. If your uncle is maximizing his profit, what is the value of the marginal product of the last worker he hired? What is that worker’s
marginal product? 他雇佣的最后一个工人的边际产量价值是多少？这个工人的边际产量是多少？

答：Since your uncle is maximizing his profit, he must be hiring workers such that their wage equals the value of their marginal product.为了利润最大化，你的叔叔雇佣工人数量的原则是工资等于边际产量价值。因为工资是每小时6元，他们的边际产量价值也应该是6元/小时.  因为边际产量价值等于边际产量乘以价格，而价格是3元，所以最后一名工人的边际产量是2个/小时。

5. Imagine a firm that hires two types of workers—some with computer skills and some without. If technology advances, so that computers become more useful to the
firm, what happens to the marginal product of the two types? What happens to equilibrium wages? Explain, using appropriate diagrams.

答：Technological advance increases the marginal product of workers who have computer skills and decreases the marginal product of workers who don’t have such skills. 技术进步使具有电脑知识的员工边际产量增加，而不具有电脑知识的员工边际产量减少。在劳动力市场，具有电脑知识的员工边际产量增加，引起其需求曲线右移。而不具有电脑知识的员工则需求曲线左移。

6. Suppose a freeze in Florida destroys part of the Florida orange crop.
a. Explain what happens to the price of oranges and the marginal product of orange pickers as a result of the freeze. Can you say what happens to the
demand for orange pickers? Why or why not?

答：柑橘均衡量减少而价格上升。柑橘采摘者的边际产量下降。但是由于价格上升，劳动力边际产量价值也可能上升，也可能下降。所以柑橘采摘者的雇佣数量也可能增加，也可能减少。

b. Suppose the price of oranges doubles and the marginal product falls by 30 percent. What happens to the equilibrium wage of orange pickers?

答：增加。

c. Suppose the price of oranges rises by 30 percent and the marginal product falls by 50 percent. What happens to the equilibrium wage of orange pickers?

答：减少。

7. During the 1980s and 1990s the United States experienced a significant inflow of capital from other countries. For example, Toyota, BMW, and other foreign car companies built auto plants in the United States.
a. Using a diagram of the U.S. capital market, show the effect of this inflow on the rental price of capital in the United States and on the quantity of capital
in use. 用一份美国资本市场图来说明资本流入对资本租赁价格和资本使用量的影响。

答：

b. Using a diagram of the U.S. labor market, show the effect of the capital inflow on the average wage paid to U.S. workers.

答：The increase in capital increases the marginal product of labor and the value of marginal product of labor for any given quantity of labor.  Figure 10 shows this as a shift in the demand for labor from D₁ to D₂. 美国国内资本增加，使劳动力的边际产量和边际产量价值增加，引起劳动力需求曲线右移，所以工人工资上涨，工人就业数量增加。

8. Suppose that labor is the only input used by a perfectly competitive firm that can hire workers for $50 per day 每个工人日工资50元. The firm’s production function is as follows:
DAYS OF LABOR 劳动力天数          UNITS OF OUTPUT
0                         0
1                         7
2                         13
3                         19
4                         25
5                         28
6                         29
Each unit of output sells for $10. Plot the firm’s demand for labor. How many days of labor should the firm hire? Show this point on your graph.

答：应该雇佣4人。

9. (This question is challenging.) In recent years some policymakers have proposed requiring firms to give workers certain fringe benefits附加福利. For example, in 1993 President Clinton proposed requiring firms to provide health insurance to their workers. Let’s consider the effects of such a policy on the labor market.
a. Suppose that a law required firms to give each worker $3 of fringe benefits for every hour that the worker is employed by the firm. How does this law
affect the marginal profit that a firm earns from each worker? How does the law affect the demand curve for labor? Draw your answer on a graph with the cash wage on the vertical axis.

答：如果企业原来就实行每小时3元额外补贴，则对其没有影响。如果原来没有实行，则影响如下。

b. If there is no change in labor supply, how would this law affect employment and wages?

答：如上图。

c. Why might the labor supply curve shift in response to this law? Would this shift in labor supply raise or lower the impact of the law on wages and
employment?

答：为何劳动供给曲线也会因这项法律而移动？劳动力供给的移动，削弱还是增强了这项法令的效果。

答：上述分析是不完整的，因为忽视了这样的事实，工人对这个每小时3元补贴很看重. 结果时劳动力供应曲线右移。一般来讲，工人们偏好现金胜于其它形式的福利, 因此，3元补贴对工人来说，没有现金值钱。但是，3美元的额外补贴政策也有其它优势  (1) 3元补贴免税;  (2) 公司集团买健康保险比个人单独买便宜. 因此，这个3元额外补贴政策，是否值3元，取决于哪个因素起决定作用。

该图表示，人们对3元补贴评价高于3元现金，所以，劳动力供应曲线偏移量大，导致工资下降高于3元。
d. As Chapter 6 discussed, the wages of some workers, particularly the unskilled and inexperienced, are kept above the equilibrium level by minimum-wage laws. What effect would a fringe-benefit mandate have for these workers? 强制福利政策对这些工人有何影响？

答：因为最低工资法保护，增加额外补贴3元后，也不允许降低部分低工资员工工资。这样会导致失业增加，因为公司不会支付高于工人边际产品价值的工资。