Returns to Scale – Increasing, Constant & Decreasing
In the long run, a firm can change the scale of production by varying all factors in the same proportion. Returns to scale explain how output responds.
1. Meaning of Returns to Scale
Returns to scale refer to the proportionate change in output when all inputs are changed in the same proportion in the long run.
Example:
- Doubling both labour and capital → what happens to output?
2. Types of Returns to Scale
1. Increasing Returns to Scale (IRS)
When output increases more than proportionately to a given proportionate increase in all inputs.
Example:
- Inputs doubled → output more than doubles.
Reasons:
- Better division of labour and specialisation.
- Indivisibilities of capital (large machines more efficient).
- Managerial and technical economies.
2. Constant Returns to Scale (CRS)
When output increases in the same proportion as all inputs.
Example:
- Inputs doubled → output exactly doubles.
3. Decreasing Returns to Scale (DRS)
When output increases less than proportionately compared to increase in all inputs.
Example:
- Inputs doubled → output less than doubles.
Reasons:
- Managerial difficulties in controlling large organisation.
- Coordination and communication problems.
- Overcrowding of management.
Stage 1"Increasing returns to scale"
↓
Stage 2"Constant returns to scale"
↓
Stage 3"Decreasing returns to scale"
3. Numerical Illustration (Conceptual)
| Scale Factor (Inputs) | Output (Units) | Type of Return |
|---|---|---|
| 1× (L, K) | 100 | Base |
| 2× (2L, 2K) | 250 | Increasing RS |
| 3× (3L, 3K) | 300 | Decreasing RS |
Identifying Returns to Scale
| Step 1 (Compare percentage change in output with percentage change in all inputs.) | |
| Add: Step 2 (If output % change > input % change → Increasing RS.) | |
| Add: Step 3 (If output % change = input % change → Constant RS.) | |
| Add: Step 4 (If output % change < input % change → Decreasing RS.) |
4. Difference between Returns to a Factor and Returns to Scale
Returns to a Factor
- Short run concept
- One factor variable, others fixed
- Explained by Law of Variable Proportions
VS
Returns to Scale
- Long run concept
- All factors varied in same proportion
- Explains increasing/constant/decreasing RS
5. Quick Revision Points
- Returns to scale: effect on output when all inputs change in same proportion.
- Types: increasing, constant, decreasing.
- Short run → returns to a factor; long run → returns to scale.
6. Quiz Time 🎯
Test Your Knowledge
Question 1 of 5
1. Returns to scale is a: