Demand for Labour

The demand for labour is fundamentally different from the demand for consumer goods. Firms do not hire workers for their own sake — they hire workers because of the output those workers can produce and sell. This insight underpins one of the most important concepts in labour economics: derived demand.

Derived Demand

Key Definition: The demand for labour is a derived demand — it is derived from (depends upon) the demand for the final good or service that labour is used to produce.

If consumers increase their demand for electric vehicles, firms such as Jaguar Land Rover will need to hire more engineers, assembly-line workers, and battery technicians. Conversely, a fall in demand for printed newspapers reduces the demand for journalists and print workers.

This principle was formalised by Alfred Marshall (1890) in his Principles of Economics. Marshall identified four conditions that determine the elasticity of derived demand (Marshall's Rules of Derived Demand):

Marshall's Rule	Explanation	Example
Substitutability of other factors	The easier it is to substitute capital for labour, the more elastic the demand for labour	Self-checkout machines replacing retail cashiers
Elasticity of demand for the final product	The more price-elastic the demand for the product, the more elastic the demand for labour	Fast-fashion garment workers vs. bespoke tailors
Proportion of labour cost to total cost	The greater labour's share of total costs, the more elastic the demand for labour	Labour-intensive care homes vs. automated factories
Elasticity of supply of other factors	The more elastic the supply of substitute factors, the more elastic labour demand	Readily available robotic welding arms vs. scarce specialist equipment

Exam Tip: Marshall's Rules are frequently tested in 25-mark essay questions. You do not need to memorise all four in isolation — instead, practise applying each rule to a real-world industry. Examiners reward application over recall.

Marginal Revenue Product (MRP) Theory

The neoclassical theory of labour demand was developed by John Bates Clark (1899) and refined by John Hicks (1932) in The Theory of Wages. The central proposition is that a profit-maximising firm will hire workers up to the point where the marginal revenue product of labour (MRP_L) equals the marginal cost of labour (MCL).

Key Definitions

Marginal Physical Product of Labour (MPP_L): The additional output produced by employing one more worker, holding all other inputs constant.
Marginal Revenue Product of Labour (MRP_L): The additional revenue a firm earns from employing one more worker. Calculated as:

MRP_L = MPP_L × MR

In a perfectly competitive product market, MR = Price, so:

MRP_L = MPP_L × P

Numerical Example

Workers	Total Output	MPP_L	Price (£)	MRP_L (£)
1	10	10	5	50
2	22	12	5	60
3	32	10	5	50
4	40	8	5	40
5	46	6	5	30
6	50	4	5	20

Notice that MPP_L initially rises (due to specialisation and division of labour) but then falls — this reflects the law of diminishing marginal returns, which states that as additional units of a variable factor (labour) are added to fixed factors (capital, land), the marginal product eventually declines.

If the wage rate is £40 per worker, the firm hires 4 workers (where MRP_L = W = £40). Hiring a 5th worker would add only £30 of revenue but cost £40 — reducing profit.

The MRP Curve as the Demand Curve for Labour

The downward-sloping portion of the MRP_L curve is the firm's demand curve for labour in a competitive labour market. As the wage falls, the firm moves down the MRP_L curve and hires more workers; as the wage rises, the firm moves up and hires fewer.

Shifts in the demand for labour (shifts in the MRP_L curve) occur when:

Change in demand for the final product — If demand for the good rises, the price rises, so MRP_L = MPP_L × P increases at every level of employment. The demand curve for labour shifts right.
Change in the productivity of labour — Training, better technology, or improved management raises MPP_L, shifting MRP_L right.
Change in the price of substitute factors — If capital becomes cheaper, firms may substitute capital for labour, shifting the demand for labour left.
Change in the price of complementary factors — If a complementary input becomes cheaper (e.g., cheaper raw materials), firms may expand output and hire more labour.

Factors Affecting the Demand for Labour in Practice

While MRP theory provides the theoretical framework, real-world labour demand is also influenced by:

Regulation and employment law — The UK's Employment Rights Act 1996 and Working Time Regulations 1998 increase the non-wage costs of employment (sick pay, holiday entitlement, redundancy pay), which may reduce demand for permanent staff and increase demand for agency or zero-hours workers.
Technological change — The Bank of England estimated in 2015 that up to 15 million UK jobs were at risk of automation. Routine manual and cognitive tasks are most vulnerable, while creative, caring, and complex problem-solving roles are least substitutable.
Globalisation — Offshoring of manufacturing to lower-wage economies (e.g., Bangladesh, Vietnam) reduces domestic labour demand in those sectors.
Exchange rates — A depreciation of sterling increases export competitiveness, raising the demand for the product and therefore the derived demand for UK labour in export industries.

Exam Tip: When evaluating MRP theory, always note its assumptions: perfect competition in product and labour markets, homogeneous labour, and perfect information. In reality, these rarely hold. Firms often cannot precisely calculate MRP_L, and wages are frequently set by negotiation, custom, or government regulation rather than by marginal productivity alone.

Evaluation of MRP Theory

Strengths

Provides a clear, logical framework linking wages to productivity.
Explains why highly productive workers (e.g., Premier League footballers) earn vastly more than low-productivity workers.
Underpins policy arguments for education and training to raise wages.

Weaknesses and Limitations

Measurement difficulties — In many jobs (teaching, nursing, management), it is extremely difficult to isolate one worker's marginal contribution to revenue.
Imperfect markets — Most labour markets are not perfectly competitive. Employers often have monopsony power (covered in Lesson 4), and workers may have trade union bargaining power (Lesson 5).
Non-wage factors — Firms consider many factors beyond MRP: team dynamics, company culture, future potential, and legal constraints.
Backward-looking — MRP theory assumes firms react to current productivity, but hiring decisions are often forward-looking and based on expected future demand.
Criticisms from institutional economists — Lester (1946) surveyed firms and found that most did not consciously equate MRP with wages. Machlup (1946) countered that firms behave as if they do, much as a billiards player obeys the laws of physics without knowing them.

The Elasticity of Demand for Labour — A Preliminary Note

The responsiveness of the quantity of labour demanded to a change in the wage rate is measured by the wage elasticity of demand for labour. This concept is explored in greater depth in Lesson 3, but it is worth noting here that the elasticity depends on the factors identified in Marshall's Rules (see the table at the top of this lesson).

A firm that can easily replace workers with machines (high substitutability) will have a more elastic demand for labour — a wage increase leads to a proportionally larger fall in employment. In contrast, a firm that relies on irreplaceable human skills (e.g., a theatre company) will have inelastic demand — employment changes little even when wages rise.

Labour Demand and the Business Cycle

The demand for labour is also cyclical — it rises during economic booms and falls during recessions:

Phase	Effect on Labour Demand	UK Example
Expansion	Rising consumer spending increases product demand, raising derived demand for labour	2013–2019: UK employment rose by 2.7 million
Recession	Falling demand for goods/services reduces derived demand; firms shed labour	2008–2009 financial crisis: UK unemployment rose from 5.2% to 7.9%
Recovery	Firms initially increase hours/overtime before hiring new workers	Post-COVID 2021: vacancies hit record 1.3 million

Labour hoarding is the practice of retaining workers during a downturn even when MRP_L temporarily falls below the wage. Firms do this to avoid the costs of firing and rehiring (recruitment, training, loss of firm-specific human capital). The UK's furlough scheme (Coronavirus Job Retention Scheme, 2020–2021) effectively subsidised labour hoarding, peaking at 8.9 million employees furloughed in May 2020.

Exam Tip: When discussing the demand for labour, always consider the time dimension. In the short run, demand for labour may be relatively inelastic because firms cannot easily adjust their capital stock. In the long run, firms can invest in automation, relocate production overseas, or restructure their operations, making demand more elastic.

Summary

Concept	Key Point
Derived demand	Labour demanded because of demand for the final product
MRP_L	Additional revenue from one more worker = MPP_L × MR
Hiring rule	Hire where MRP_L = MCL (or MRP_L = W in competitive markets)
MRP curve	Downward-sloping portion = demand curve for labour
Shifts in demand	Caused by changes in product demand, productivity, technology, factor prices
Elasticity of demand	Depends on substitutability, product demand elasticity, labour cost share, time period
Business cycle	Demand for labour is cyclical; labour hoarding smooths fluctuations

Exam Tip: In a 15-mark question on "factors affecting the demand for labour," structure your answer around derived demand, MRP theory, and then real-world factors (technology, regulation, globalisation). Always include at least one diagram and one evaluative point to access the top mark band.

Key Diagrams to Practise

For this topic, you should be able to draw and annotate the following diagrams from memory:

The MRP curve — showing diminishing marginal returns, with MRP_L on the vertical axis and quantity of labour on the horizontal axis. Mark the profit-maximising employment level where MRP_L = W.
A shift in the demand for labour — showing how an increase in product demand shifts the MRP_L curve rightward, increasing both the equilibrium wage and employment.
The derived demand relationship — a two-panel diagram showing the product market on the left (increase in demand for the good) and the labour market on the right (resulting shift in demand for labour). This demonstrates the link between product and factor markets clearly.

Exam Tip: Diagrams are not optional at A-Level. A well-drawn, fully labelled diagram can earn up to 4 marks on its own in a 15-mark question. Always label axes, curves, equilibrium points, and any shifts. Use arrows to show the direction of change and annotate the new equilibrium.