平狄克微观经济学第六版课后答案

1. Why is a firm’s demand for labor curve more inelastic when the firm has monopoly power in the output market than when the firm is producing competitively?

The firm’s demand curve for labor is determined by the incremental revenue from

hiring an additional unit of labor known as the marginal revenue product of labor:

MRPL = (MPL)(MR), the additional output (“product”) that the last worker produced,

times the additional revenue earned by selling that output. In a competitive industry,

the marginal revenue curve is perfectly elastic and equal to price. For a monopolist,

marginal revenue is downward sloping. As more labor is hired and more output is

produced, the monopolist will charge a lower price and marginal revenue will diminish.

All else the same, marginal revenue product will be smaller for the monopolist. This

implies that the marginal revenue product for the monopolist is more inelastic than for

the competitive firm.

2. Why might a labor supply curve be backward bending?

A backward-bending supply curve for labor may occur when the income effect of an

increase in the wage rate dominates the substitution effect. Labor supply decisions are

made by individuals choosing the most satisfying combination of work and other

(leisure) activities. With a larger income, the individual can afford to work fewer

hours: the income effect. As the wage rate increases, the value of leisure time (the

opportunity cost of leisure) increases, thus inducing the individual to work longer hours:

the substitution effect. Because the two effects work in opposite directions, the shape

of an individual’s labor supply curve depends on the individual’s preferences for income,

consumption, and leisure.

3. How is a computer company’s demand for computer programmers a derived demand?

A computer company’s demand for inputs, including programmers, depends on how

many computers it sells. The firm’s demand for programming labor depends on (is

derived from) the demand it faces in its market for computers. As demand for

computers shifts, the demand for programmers shifts.

4. Compare the hiring choices of a monopsonistic and a competitive employer of workers. Which will hire more workers, and which will pay the higher wages? Explain.

Since the decision to hire another worker means the monopsonist must pay a higher

wage for all workers, and not just the last worker hired, its marginal expenditure curve

lies above the input supply curve (the average expenditure curve). The monopsonist’s

profit-maximizing input demand, where the marginal expenditure curve intersects the

marginal revenue product curve, will be less than the competitor’s profit-maximizing

input choice, where the average expenditure curve intersects the demand curve. The

monopsonist hires less labor, and the wage paid will be less than in a competitive

market.

5. Rock musicians sometimes earn over $1 million per year. Can you explain such large incomes in terms of economic rent?

Economic rent is the difference between the actual payment to the factor of production

and the minimum amount that the factor is willing to accept. In this case, you might

assume that there are a limited number of top-quality rock musicians who will continue

to play rock music no matter what they are paid. This results in a perfectly inelastic

supply curve, or something close to it. Given the high demand for rock music, the

wage will be very high and there will be a lot of economic rent. If there was a larger

supply of top-quality rock musicians, or a more elastic supply, then the economic rent

would be smaller.

平狄克微观经济学第六版课后答案

6. What happens to the demand for one input when the use of a complementary input increases?

If the demand for the complementary input increases, the demand for the given input

will increase as well. When demand for the complementary input increases, there is

an increase in the quantity hired and possibly the price paid. Both of these changes

will increase the MRP of the given input, and hence will increase the quantity hired

and possibly the price paid. Whether the prices of the inputs increases depends on the

degree of monopsony power on the part of the firm.

7. For a monopsonist, what is the relationship between the supply of an input and the marginal expenditure on it?

The decision to increase employment means the monopsonist must pay all units the

higher price, and not just the last unit hired. Therefore, its marginal expenditure

curve lies above the input supply curve (the average expenditure curve). Hiring more

labor will increase the marginal expenditure, which will increase the average

expenditure. If the average expenditure is increasing, then the marginal expenditure

must be greater than the average expenditure.

8. Currently the National Football League has a system for drafting college players by which each player is picked by only one team. The player must sign with that team or not play in the league. What would happen to the wages of newly drafted and more experienced football players if the draft system were repealed, and all teams could compete for college players?

The National Football League draft and reserve clause (a primary issue in the 1987-

1988 season’s strike) creates a monopsonist cartel among the owners of NFL teams. If

the draft system were repealed, competition among teams would increase wages of

football players to the point where the marginal revenue product of each player would

be equal to the player’s wage.

9. The government wants to encourage individuals on welfare to become employed. It is considering two possible incentive programs for firms.

A. Give the firm $2 per hour for every individual on welfare who is hired.

B. Give each firm that hires one or more welfare workers a payment of $1000 per year, irrespective of the number of hires.

To what extent is each of these programs likely to be effective at increasing the employment opportunities for welfare workers?

Firms will hire additional labor as long as the extra benefit is greater than the extra

cost of hiring the worker, or until MRPL = w. Option A would be effective because if

the firm receives $2 per hour for every welfare worker hired then the effective wage

paid, w, will fall and the firm will find it optimal to hire more labor until the benefits

(MRPL) again equal the costs (w) at the margin. Option B would be effective at

increasing employment opportunities also in that if the firm hires an individual who

has been on welfare they will then receive $1000. However, plan B is not

necessarily as effective as plan A given the firm only receives one lump sum payment

regardless of the number of welfare workers hired. In this case the firm only has an

incentive to hire the one welfare worker, though they may of course choose to hire

more than one welfare worker.

10. A small specialty cookie company, whose only variable input is labor, finds that the average worker can produce 50 cookies per day, the cost of the average worker is $64 per day, and the price of a cookie is $1. Is the cookie company maximizing its profit? Explain.

The marginal product of labor is 50 (cookies per day) and the price per cookie is 1

($ per cookie) so the marginal revenue product is $50/day. Since this is less than the

wage of $64 per day the cookie company is not maximizing profit. They are