Worker productivity is a major driver of how many workers firms want to hire. When productivity changes, the value of each worker’s contribution changes, shifting firms’ labor demand and altering market outcomes.

Core idea: productivity shifts labor demand

A firm’s labor demand reflects how many workers it is willing to hire at each wage rate, based on what each worker adds to the firm’s revenue. If workers become more productive, each worker tends to generate more output, so hiring labor becomes more attractive at any given wage.

What “worker productivity” means in this context

A marginal product of labor (MPL) curve: as more workers are hired while capital is fixed, each additional worker typically adds less extra output. This makes the MPL curve slope downward, illustrating diminishing marginal returns in the short run. Source

Productivity changes are usually changes in MPL, caused by improvements in skills, technology, capital equipment, or work organisation.

The link from productivity to labour demand

Labour demand is derived demand: it depends on the demand for the product the workers help produce. A productivity increase strengthens this derived demand because each worker now produces more output that can be sold.

Revenue logic: why labour demand shifts right

If MPL rises, then for the same number of workers:

• the firm can produce more output, and

• selling that extra output increases revenue (given the output market conditions).

This raises the marginal benefit of hiring labour, so the firm is willing to hire:

• more workers at the same wage, or

• the same number of workers even at a higher wage.

Graphically, the labour demand curve shifts right when productivity increases (and shifts left when productivity falls).

Expressing the relationship with MRP

Marginal revenue product of labor (MRP) plotted against labor: the curve slopes downward as additional workers contribute less extra output and (in market power cases) the firm’s marginal revenue falls with output. This is the graphical counterpart to $MRP_L = MP_L \times MR$, and it is the curve firms compare to the wage when choosing how many workers to hire. Source

Holding the output market term ($MR$) constant, an increase in $MP_L$ increases $MRP_L$, which increases the firm’s willingness to hire labour at any wage, shifting labour demand rightward.

Common causes of productivity changes

A worker’s productivity can change due to factors that affect output per worker, such as:

• Human capital: training, education, experience, better health

• Technology: improved software, tools, automation that complements labour

• Capital deepening: more or higher-quality machines per worker

• Process improvements: better management, scheduling, reduced downtime

• Task specialisation: division of labour that raises output per hour

How to describe the shift correctly (AP-style precision)

When productivity changes, keep the following distinctions clear:

• A productivity change shifts the labour demand curve (it is not movement along the curve caused by a wage change).

• The direction depends on the sign of the productivity change:

  • Productivity up ($MPL \uparrow$) $\Rightarrow$ labour demand shifts right

  • Productivity down ($MPL \downarrow$) $\Rightarrow$ labour demand shifts left

• The mechanism is: more productive workers add more output and revenue, raising the value of hiring them at each wage.

What stays constant in this subsubtopic

To isolate the effect of productivity on labour demand, assume other determinants are unchanged, especially:

• the output price (so changes are attributed to productivity, not product demand conditions)

• the wage rate (which determines the quantity demanded, not the position of demand)