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Tutorial 12: Non-competitive Labor Markets

 

Factor Markets with Wage-setting Power

In the last Tutorial we developed a model of the labor market where firms hiring labor have no market power, i.e., they take the market-set wage rate as given. In Tutorial 12 we explore how that model is changed when individual firms have enough market power to set the wage they pay below the competitive equilibrium.

First an important reminder. In Tutorials 11 and 12 the firm plays a new role as a buyer of inputs. It is important that you keep this new role in mind. Failure to to keep the firm's roles in mind can make it easy to confuse models of input markets with models of product markets.

Here are the assumptions made to keep this model simple.

  1. The firm produces a product using only capital, K, and labor, L.
  2. The amount of capital available is fixed (i.e., the firm is producing in the short run).
  3. This firm is the only firm hiring labor in this area.
  4. All the workers hired by the firm have exactly the same skill level.

Our single employer, called a monopsony, faces the entire market supply of skilled labor. As a result, our firm must offer higher wages if it wants to attract more workers. [Remember, the quantity of labor supplied in the market varies directly with wages -- people generally work more at higher wages.] When it does raise wages, it will do so for all its employees, not just the new ones. [If this sounds far fetched, remember, if a firm does not cover the opportunity costs of its workers, it will lose those workers to better paying jobs...] Facing an upward sloping labor market supply curve has significant implications for the firm's marginal expenditures on labor.

Let's say the firm hires its first worker at $10 per hour. If it wants to hire another worker, it will have to raise wages to $12 per hour. The marginal expenditure, ME, on the second worker includes the $12 per hour wage plus an additional $2 per hour for the first worker. So ME = $14, which exceeds the wage rate paid the second worker. Continuing with this example, suppose a third worker will accept no less than $14 per hour. The ME on this third worker is $14 + $2 + $2 = $18. If you continue in the same fashion you will discover that the rate of increase in ME is twice as high as the rate of increase in wages.

Graphically, a model of a wage-setting firm is different from that of a wage-taking firm in this one respect. Figure 1 illustrates this difference. The wage-setting firm faces an upward sloping labor supply curve, S1, and a marginal expenditure curve, ME1, that is also upward sloping, but which rises twice as fast as supply.

 

Figure 1


Graph showing the optimal wage and hiring for a wage-setting firm.

 

The Input Purchasing Decision of the Firm Top of page.

A profit-maximizing firm will hire labor until the marginal benefit of the last worker hired equals the marginal cost of employing her. That marginal cost, referred to as marginal expenditure, ME1, varies directly with the quantity of labor hired. The marginal benefit to the firm of hiring each additional worker is measured by how much revenue the output of that worker adds to the total, which is called marginal revenue product (MRP1). The intersection of MRP1 and ME1 determines the profit maximizing level of labor for this firm to hire. In this case the firm will hire L* = 20,000 labor days per period. The last worker hired adds just as much to revenue as to cost, but all previous workers added more to revenue than to cost -- the difference going to the firm as additional profit.

Notice that there has been no mention of how much the firm will pay these workers. That's because, after the profit-maximizing level of hiring is determined, the firm will know what the lowest wage that must be offered to attract all L* workers. That "minimum willingness to accept" is found on the labor supply curve, S1. (Need a review of reservation prices?) So at L*, draw a vertical line up from the x-axis until it hits S1, then continue that line horizontally until it intersects the vertical axis. Doing so reveals that the firm need only offer a wage rate of W* = $100 per day to fill their need for 20000 worker days per period.

 

Wage-setting Power Top of page.

In Tutorial 10 we discovered that, for a price-setting firm in a product market, MR = P + P·(1/Ed). By a similar mathemagical derivation we can show that, for a monopsony, ME = w + w·(1/Es). [Ed and Es are used here to represent price elasticity of demand and supply respectively.]

At the profit-maximizing level of hiring, ME = MRP, i.e.,

w + w·(1/Es) = MRP.

Rearranging terms;

(MRP - w)/w = 1/Es

with monopsony power, w < MRP (remember, w is determined by the labor market supply, it is the lowest wage the last hired worker is willing to accept). The difference between MRP and w measures the "markdown" in wages (as a percent of the wage rate). That is, how much below what a worker is worth (as shown by MRP) a wage-setting firm can pay. It is a tribute to the firm's wage-setting power... a sort of Lerner's index of labor market power.

The size of the markdown is inversely related to Es;

  • the more elastic labor supply, the smaller the wage-setting power of the firm.
  • the more inelastic S, the larger the wage-setting power of the firm.

 

This is a good time to start, or review, GFE 28.

Now it's time to "do the thing".

Click on the following link to download the Monopsony Labor Market Workbook. Work through Questions 1 - 7. This will let you improve your understanding of how a wage-setting firm chooses to hire inputs so as to maximize profit.

Return here when you have finished.

Need help downloading the Excel file?

 

 

In this Tutorial we explored a model of the labor market where firms hiring labor have market power, i.e., they set the wage rate below the marginal revenue product of the workers. Inthe next part we explore the social cost of having firms with wage-setting power hire labor.