Which of the following factors may not affect the efficiency of labour?

Analyze the question: The question asks which factor "may not" affect the efficiency of labour. Efficiency of labour means how productive workers are, meaning the output each worker produces in a given time.

Explain the concept: Labour efficiency (productivity) depends on things that change a worker's skill, motivation, health, or working conditions. These include:

• Education and training: These give workers skills and knowledge, so they produce more and better.
• Welfare services: Health care, housing, transport allowances and similar benefits keep workers healthy and motivated, so they work harder and are absent less often.
• Quality of other factor inputs: Good machines, tools, land and raw materials let a worker produce more. A worker with a modern machine is more productive than one with a hand tool.
• Race and colour: These are physical characteristics. They have no link to a person's ability to work, skill, or productivity.

Step-by-step elimination:

• A: Education and training directly raise skill, so they affect efficiency. ❌
• B: Welfare services improve health and morale, so they affect efficiency. ❌
• C: Race and colour do not determine how productive a worker is. ✅
• D: Better capital and materials raise output per worker, so they affect efficiency. ❌

Answer: The only factor that does not influence labour efficiency is race and colour of the workforce.

Exam tip: In "which may not affect" questions, look for the option that is a fixed personal trait (such as race, colour or tribe) rather than something that can change a worker's skill, health, motivation or tools. Anything about training, health, pay, welfare or equipment usually affects productivity.