A monopsonistic labor market is defined by limited buyer competition for workers. This structure changes how wages are set, what the firm’s labor supply looks like, and how employment responds to changing conditions.

Core idea: a single (or dominant) buyer of labor

What “monopsony” means

A monopsony exists when one firm is the only buyer, or the overwhelmingly dominant buyer, of a particular type of labor in a market.

In practice, monopsony power can arise even if there are multiple employers, as long as one employer has enough hiring share that workers have few close alternatives.

Key characteristic from the AP syllabus

The defining feature is that the firm faces the market labor supply, meaning it cannot hire any quantity of labor at a fixed wage. Instead, it must consider that higher employment generally requires offering a higher wage.

Wage-setting power and the firm’s labor supply curve

Wage setter, not wage taker

A monopsonist is a wage setter: the wage is influenced by the firm’s hiring decision because workers’ willingness to work increases with the wage.

This contrasts with a competitive labor market, where each firm faces a perfectly elastic (horizontal) labor supply at the market wage and therefore takes the wage as given.

This figure illustrates a monopsony labor market with a binding minimum wage and how that policy can alter the firm’s marginal cost of labor. When the minimum wage creates a flat segment of the marginal cost curve over a range, the profit-maximizing employment choice can rise relative to the unregulated monopsony outcome. It’s a helpful visual for connecting wage-setting power to policy analysis, especially when comparing monopsony to perfect competition. Source

Upward-sloping labor supply to the firm

In a monopsony, the labor supply curve to the firm is upward sloping:

This graph shows the labor supply curve the monopsonist faces (market $S_L$) and the marginal cost of labor curve ($MC_L$). Because raising the wage to hire one more worker typically requires paying a higher wage to all workers, $MC_L$ lies above the labor supply curve. This wedge is the key graphical reason monopsonies hire fewer workers at a lower wage than in competitive labor markets. Source

• To attract more workers from unemployment, from other regions, or away from other employers, the firm typically must offer a higher wage.

• As a result, the wage paid is read off the labor supply curve at the chosen employment level.

A useful way to interpret this is that the market labor supply and the firm’s labor supply are effectively the same curve when the firm is the dominant buyer.

Why monopsony power happens (sources of limited competition)

Few alternative employers (concentration)

Monopsony is more likely when:

• One employer dominates hiring in a town/region (for example, a major hospital system or manufacturing plant).

• An occupation is highly specialised locally, so only one firm demands that specific skill set.

Worker immobility and switching frictions

Even if other employers exist, monopsony power can persist when workers face barriers to changing jobs, such as:

• Geographic immobility (moving costs, housing constraints, family ties)

• Occupational immobility (credentials, licensing, firm-specific skills)

• Search and information costs (time and uncertainty involved in finding offers)

• Non-compete clauses or delayed hiring cycles

These factors reduce workers’ outside options and make the firm’s labor supply less responsive.

Differentiated jobs and non-wage factors

When jobs differ in location, hours, scheduling, safety, culture, or benefits, workers may not view employers as perfect substitutes. This can give a firm wage-setting power even without being the only employer.

How to recognise monopsonistic labour markets on graphs (conceptually)

What the firm “faces”

In a monopsony, the firm faces:

• An upward-sloping labor supply: higher wages are required to hire more labor.

• The wage is not fixed by the market for the firm; it is influenced by the firm’s chosen employment level.

Graph-reading cues (without doing calculations):

This diagram shows monopsony wage and employment determination: the firm chooses employment where labor demand (MRP, labeled $D_L$) intersects $MC_L$ at $L_m$. The wage is then read off the labor supply curve at that employment level, giving $W_m$. The picture reinforces that, in monopsony, wage and employment are jointly determined by the upward-sloping supply and the higher marginal cost of hiring. Source

• The wage is determined on the labor supply curve rather than by a horizontal wage line.

• Employment decisions and wage outcomes are jointly linked through that supply curve.

Common misunderstandings to avoid

• Monopsony does not require literally one employer; dominance and limited worker alternatives can be enough.

• Wage-setting power does not mean the firm can pick any wage costlessly; paying less generally reduces the quantity of labor supplied to the firm.

• Monopsony is about the buy-side of the labor market (hiring), not the sell-side of the output market.