1. Input Demand: The Labor and Land Markets
Input Markets: Basic Concepts Labor Markets Land Markets The Firm’s Profit-Maximization Condition in Input Markets Input Demand Curves Resource Allocation and the Mix of Output in Competitive Markets

2. INPUT DEMAND: THE LABOR AND LAND MARKETS
FIGURE Firm and Household Decisions

3. INPUT MARKETS: BASIC CONCEPTS
DEMAND FOR INPUTS: A DERIVED DEMAND
derived demand The demand for resources (inputs) that is dependent on the demand for the outputs those resources
can be used to produce.
productivity of an input The amount of output produced per unit of that input.
Inputs are demanded by a firm if and only if households demand the good or service
produced by that firm.

4. INPUT MARKETS: BASIC CONCEPTS
INPUTS: COMPLEMENTARY AND SUBSTITUTABLE
Inputs can be complementary or substitutable.
DIMINISHING RETURNS
marginal product of labor (MPL) The additional output produced by one additional unit of labor.

5. INPUT MARKETS: BASIC CONCEPTS
TABLE Marginal Revenue Product per Hour of Labor in Sandwich Production (One Grill)
(1) TOTAL LABOR UNITS (EMPLOYEES)
(2) TOTAL PRODUCT (SANDWICHES PER HOUR)
(3) MARGINAL PRODUCT OF LABOR (MPL) (SANDWICHES PER HOUR)
(4) PRICE (PX) (VALUE ADDED PER SANDWICH)a
(5) MARGINAL REVENUE PRODUCT (MPL X PX) (PER HOUR) - 1 10 $
.50
5.00 2 25 15
7.50 3 35 4 40 5
2.50 42
1.00 6
aThe “price” is essentially profit per sandwich; see discussion in text.

6. INPUT MARKETS: BASIC CONCEPTS
MARGINAL REVENUE PRODUCT
marginal revenue product (MRP) The
additional revenue a firm earns by employing one additional unit of input, ceteris paribus.
MRPL = MPL x PX

7. INPUT MARKETS: BASIC CONCEPTS
FIGURE 10.2 Deriving a Marginal Revenue Product Curve from Marginal Product

8. LABOR MARKETS A FIRM USING ONLY ONE VARIABLE
FACTOR OF PRODUCTION: LABOR
A profit-maximizing firm will add inputs—in the case of labor, it will hire workers—as long as the marginal revenue product of that input exceeds the market price of that input—in the case of labor, the wage.

9. LABOR MARKETS
FIGURE Marginal Revenue Product and Factor Demand for a Firm Using One Variable Input (Labor)
When a firm uses only one variable factor of production, that factor’s marginal revenue
product curve is the firm’s demand curve for that factor in the short run.

10. LABOR MARKETS
Comparing Marginal Revenue and Marginal Cost to Maximize Profits
FIGURE The Two Profit-Maximizing Conditions Are Simply Two Views of the Same Choice Process

11. LABOR MARKETS FIGURE 10.5 The Trade-Off Facing Firms
Assuming that labor is the only variable input, if society values a good more than it costs
firms to hire the workers to produce that good, the good will be produced. In general, the
same logic also holds for more than one input. Firms weigh the value of outputs as
reflected in output price against the value of inputs as reflected in marginal costs.

12. LABOR MARKETS A FIRM EMPLOYING TWO VARIABLE FACTORS
OF PRODUCTION IN THE SHORT AND LONG RUN
In firms employing just one variable factor of production, a change in the price of that factor affects only the demand for the factor itself. When more than one factor can vary, however, we must consider the impact of a change in one factor price on the demand for other factors as well.

13. LABOR MARKETS
Substitution and Output Effects of a Change in Factor Price
TABLE Response of a Firm to an Increasing Wage Rate
TECHNOLOGY
INPUT REQUIREMENTS PER UNIT OF OUTPUT
UNIT COST IF PL = $1 PK = $1 (PL x L) + (PK x K)
UNIT COST IF PL = $2 PK = $1 (PL x L) + (PK x K) K L
A (capital intensive) 10 5
$15
$20
B (labor intensive) 3
$13
$23

14. TO PRODUCE 100 UNITS OF OUTPUT TOTAL CAPITAL DEMANDED
LABOR MARKETS
TABLE The Substitution Effect of an Increase in Wages on a Firm Producing 100 Units of Output
TO PRODUCE 100 UNITS OF OUTPUT
TOTAL CAPITAL DEMANDED
TOTAL LABOR DEMANDED
TOTAL VARIABLE COST
When PL = $1, PK = $1, firm uses technology B
300
1,000
$1,300
When PL = $2, PK = $1, firm uses technology A
500
$2,000

15. LABOR MARKETS
factor substitution effect The tendency of firms to substitute away from a factor
whose price has risen and toward a factor whose price has fallen.
output effect of a factor price increase
(decrease) When a firm decreases (increases) its output in response to a factor price increase (decrease), this decreases (increases) its demand for all factors.

16. LABOR MARKETS MANY LABOR MARKETS
If labor markets are competitive, the wages in those markets are determined by the interaction of supply and demand. As we have seen, firms will hire workers only as long as the value of their product exceeds the relevant market wage. This is true in all competitive labor markets.

17. LAND MARKETS
demand determined price The price of a good that is in fixed supply; it is determined exclusively by what firms and households are willing to pay for the good.
pure rent The return to any factor of production that is in fixed supply.

18. LAND MARKETS FIGURE 10.6 The Rent on Land Is Demand Determined
The supply of land of a given quality at a given location is truly fixed in supply. Its value
is determined exclusively by the amount that the highest bidder is willing to pay for it.
Because land cannot be reproduced, supply is perfectly inelastic.

19. LAND MARKETS RENT AND THE VALUE OF OUTPUT PRODUCED ON LAND
The demand for land is a derived demand. Agricultural or even desert land will be developed when there is a demand for housing because land is a key input used in the production of housing.
A firm will pay for and use land as long as the revenue earned from selling the product
produced on that land is sufficient to cover the price of the land. Stated in equation form, the firm will use land up to the point at which MRPA= PA, where A is land (acres).

20. THE FIRM’S PROFIT-MAXIMIZATION CONDITION IN INPUT MARKETS
Profit-maximizing condition for the perfectly competitive firm is
PL = MRPL = (MPL x PX)
PK = MRPK = (MPK x PX)
PA = MRPA = (MPA x PX)
where L is labor, K is capital, A is land (acres), X is output, and PX is the price of that output.

21. INPUT DEMAND CURVES SHIFTS IN FACTOR DEMAND CURVES
The Demand for Outputs
If product demand increases, product price will rise and marginal revenue product (factor demand) will increase—the MRP curve will shift to the right. If product demand declines, product price will fall and marginal revenue product (factor demand) will decrease—the MRP curve will shift to the left.
The Quantity of Complementary and Substitutable Inputs
The production and use of capital enhances the productivity of labor and normally increases the demand for labor and drives up wages.

22. INPUT DEMAND CURVES The Prices of Other Inputs Technological Change
When a firm has a choice among alternative technologies,
the choice it makes depends to some extent on relative input prices.
Technological Change
technological change The introduction of new methods of production or new products intended to increase the productivity of existing inputs or to raise marginal products.
Technological change can and does have a powerful influence on factor demands. As new products and new techniques of production are born, so are demands for new inputs and new skills. As old products become obsolete, so, too, do the labor skills and other inputs needed to produce them.

23. RESOURCE ALLOCATION AND THE MIX OF OUTPUT IN COMPETITIVE MARKETS
THE DISTRIBUTION OF INCOME
marginal productivity theory of income distribution At equilibrium, all factors of production end up receiving rewards determined by their productivity as measured by marginal revenue product.

24. LOOKING AHEAD
We have now completed our discussion of competitive labor and land markets. The next chapter takes up the complexity of what we have been loosely calling the “capital market.” There we discuss the relationship between the market for physical capital and financial capital markets, and look at some of the ways that firms make investment decisions.

25. REVIEW TERMS AND CONCEPTS
demand determined price
derived demand
factor substitution effect
marginal product of labor (MPL)
marginal productivity theory of income distribution
marginal revenue product (MRP)
output effect of a factor price increase (decrease)
productivity of an input
pure rent
technological change
Equations:
MRPL = MPL x PX
W*= MRPL