Chapter 10: Factor Markets
Factor demand
- The theory of factor demand is applicable to all factors of production but let’s focus on labor for now
Competitive factor markets
- Standard Assumptions
- Firms are price takers in the product market
- Firms are price takers in the input market
Marginal Revenue Product
- Demand for a unit of labor is a function of two things important to employers
1. Marginal productivity of the next unit of labor
- If total production could change greatly by the hiring of the next laborer, he/she would be beneficial for the firm
2. Firm must receive good value for the production
- This would be in the form of marginal revenue for the firm
- Marginal productivity of labor + marginal revenue = marginal revenue product of labor (MRPL)
- Change in total revenue/change in resource quantity = MR x MPl = P x MPl
- This is a measure of what a next unit of a resource (e.g. labor), brings to a firm
- Perfectly competitive output market, marginal revenue = price of the product
| ]]Labor input (workers/hour)]] | ]]Total product (cups/hour)]] | ]]Marginal product (MPl)]] | ]]Marginal revenue (MR=P)]] | ]]Marginal revenue product (MRPl= MPl x MR)]] |
|---|---|---|---|---|
| 0 | 0 | |||
| 1 | 25 | 25 | $.50 | $12.50 |
| 2 | 45 | 20 | $.50 | $10.00 |
| 3 | 60 | 15 | $.50 | $7.50 |
| 4 | 70 | 10 | $.50 | $5.00 |
| 5 | 75 | 5 | $.50 | $2.50 |
| 6 | 70 | -5 | $.50 | -$2.50 |
| 7 | 60 | -10 | $.50 | -$5.00 |
- From the chart of the same lemonade stand, we wouldn’t hire more than 1 worker because the marginal revenue product is maximized at that level
Profit-maximizing resource employment
If MB > MC, do more of it
If MB < MC, do less of it.
If MB = MC, stop here.
In the case of resource hiring, the marginal benefit is MRPL
The marginal cost of resource hiring is marginal resource cost (MRC)
* MRC is how much cost the firm incurs from using an additional unit of an input
* In a competitive labor market, MRC = wage (w)MRC = Change in total resource cost/change in resource quantity = wage
The profit-maximizing employer of labor would hire to the point where MRPL (marginal revenue product per labor)= MRC (marginal resource cost) = Wage
| ]]Total labor input (workers/hour)]] | ]]Product (cups/hour)]] | ]]Marginal product]] | ]]Marginal revenue]] | ]]Marginal revenue product]] | ]]Marginal resource cost (MRC = wage)]] |
|---|---|---|---|---|---|
| 0 | 0 | ||||
| 1 | 25 | 25 | $.50 | $12.50 | $7.50 |
| 2 | 40 | 20 | $.50 | $10.00 | $7.50 |
| 3 | 60 | 15 | $.50 | $7.50 | $7.50 |
| 4 | 70 | 10 | $.50 | $5.00 | $7.50 |
| 5 | 75 | 5 | $.50 | $2.50 | $7.50 |
| 6 | 70 | -5 | $.50 | -$2.50 | $7.50 |
| 7 | 60 | -10 | $.50 | -$5.00 | $7.50 |
- Based on this chart, 3 workers would help maximize the profit for the lemonade stand MRPL as Demand for Labor
- Employment and labor cost are inversely related
- As labor cost increases, employment decreases, and vice versa
- Based on the same chart above, if the wage rate rose to $10, then the lemonade owner would have to cut down to 2 employees to maximize profit

- MRPL is downward sloping like any demand curve would be, because of the diminishing marginal productivity of labor in the short run
- Demand for the overall market of labor is the sum of all of the individual firms’ MRPL curves: Market DL = SMRPL
Market wage as supply of labor
Under the assumptions of a perfectly competitive labor market, the supply of labor to the individual firm
* Is perfectly elastic
* Equal to the wageHence the firms could employ all of the workers they desire at the going market wage
In competitive markets, MRPL is the firm’s downward-sloping labor demand curve
In competitive markets, wage is the firm’s horizontal labor supply curve
Derived demand
- An increase in the demand for a resource means that at any wage, the firm wishes to employ more of that resource

- ↑D for product leads to ↑price of product which ↑MRPL. This in return ↑hiring of labor at the current wage
Determinants of resource demand
1. Product demand
- Increase in demand for a product results in an increase in the price for that product
- Higher price increases the marginal revenue product of resources used in the production for that product
- Shifts the demand for those resources to the right and vice versa for opposite scenarios
2. Productivity (output per resource unit)
- If productivity increases, the firm takes advantage due to profit motives
- Productivity of a resource is affected by a few different factors
A. Quantity of other resources A.
- A good example would be how if the working space is improved or the labor is provided with better equipment, it can boost productivity
B. Technical progress
- Improvement in technology helps boost productivity greatly
C. Quality of variable resources
- Variable resources such as a well-trained work force can help boost productivity
- Prices of other resources
Demand for one (labor) often depends upon the prices of the others such as:
1. Substitute resources
A. Substitution effect (SE)
- As firms become more machinery dependent, they would obviously cut down on their labor
B. Output effect (OE)
- With lower machine costs, production cost declines which motivates firms to produce more
- With more output production, firms now need more labor too with the lower marginal cost of producing
C. Net effect of a lower price of capital depends upon the magnitude of each effect
- If SE > OE, demand for labor falls
- If OE > SE, the demand for labor increases
2. Complementary resources
- Lower-priced machinery makes it more affordable for the firm and at the same time requires more labor
- This situation would hold true only if the labor and machinery work in complement to each other
- A good example would be transport-related companies when they face increase costs in terms of fuel etc.
- Due to this increased cost, they would utilize lower vehicles and hence there would be fewer need for the extra driver now who doesn’t have to drive anything
| ]]Labor demand increases if]] | ]]Labor demand decreases if]] |
|---|---|
| Demand for product increases, increasing the price | Demand for product decreases, reducing the price |
| Labor becomes more productive, either with more resources availability, better technology or higher quality workforce | Labor becomes less productive, either with fewer resources availability, lessened technology or poor quality workforce |
| Price of substitute resources falls and the OE > SE | Price of substitute resources falls and the OE < SE |
| Price of substitute resources rises and the OE < SE | Price of substitute resources rises and the OE > SE |
| Price of complementary resource falls | Price of complementary resource rises |
Least-cost hiring of multiple inputs
- Producers find the best cost-minimizing combination of two inputs, given the prices and production constraint
- We use the consumer’s decision as a model for the producer’s decision
There are 2 connections between production and cost
- You must produce Q* units of output. Now find the least-cost ($TC) way of doing so.
- You can only spend $TC. Now find the highest level of output (Q*)
- MPl/Pl = MPk/Pk
1. This is the least cost rule and is used to find the combination
Imagine a situation
- Input is $1 per unit
- MPL = 100 and the MPK = 10 at the current level of labor and capital
- Increasing spending on labor by $1 would increase output by 100 units
- That one extra dollar is coming from you spending one dollar less on capital
1. If MPL/PL > MPK/PK, the firm would likely increase spending on L and decrease spending on K
2. Law of diminishing marginal returns predicts that as you increase L, MPL falls
3. As you decrease K, MPK rises
| ]]Situation]] | ]]Firm will]] | ]]Which causes]] | ]]And]] | ]]Until]] |
|---|---|---|---|---|
| MPl/Pl < MPk/PK | increase Labor and decrease capital | MPl falls | MPk rises | MPl/Pl = MPk/Pk |
| MPl/Pl > MPk/PK | Increase capital and decrease labor | MPk falls | MPl rises | MPl/Pl = MPk/Pk |
Factor supply and market equilibrium
Supply of labor
- Price of labor increases, more hours of labor should be supplied (supply increases) Wage and Employment Determination
- Competitive wage is found at the intersection of labor demand and labor supply

What about Other Resources?
- The same concept would apply to even the market for capital
- Assuming that the market is in perfect competition
- MRPk = P x MPk
- Demand for capital is also derived from the marginal revenue product of capital (MRPK)

- The demand and supply operate as they normally do for any resource Imperfect Competition in Product and Factor Markets
Let’s assume that now the firms have some market power in
- Product market
- Factor (labor) market
1. Since not the firms are the price setters, the price would exceeds marginal revenue
2. This impacts the marginal revenue product function
3. MR < P: MRPm = MR x MPl < MRP
4. The result is that optimal amount of employment falls at all wages
5. In simpler terms, the monopolist hires fewer resources
Market Power in Factor Markets
- Firms with extreme market power in the factor market are called wage-setting monopsonist
- The wages are set below marginal factor cost
Key difference between monopsony and perfectly competitive labor market is
- Employer must increase the wage to increase the quantity of labor supplied
- Labor supply to the firm is upward sloping
- Marginal factor cost is now greater than the wage
| ]]Labor supplied to firms]] | ]]Necessary hourly wage]] | ]]Total wage bill (Ls x W)]] | ]]Marginal factor cost (MFC)]] |
|---|---|---|---|
| 0 | $0 | ||
| 1 | $4 | $4 | $4 |
| 2 | $5 | $10 | $6 |
| 3 | $6 | $18 | $8 |
| 4 | $7 | $28 | $10 |
| 5 | $8 | $40 | $12 |
| 6 | $9 | $54 | $14 |
- Considering the same lemonade stand, the stall owner can employ more workers by increasing wage but she would have to do the same for all existing employees
- Molly still chooses to employ where MRPL = MFC, but now wage is determined from the labor supply curve
