Which of the following factors is not a cause of diminishing returns?

Step 1: Analyze the question We need the factor that is NOT a cause of diminishing returns.

Step 2: The concept The law of diminishing returns says that when more units of a variable input are added to a fixed input (like land or capital), while technology stays the same, the extra output from each added unit eventually starts to fall.

Key conditions:

• At least one factor is fixed.
• Variable inputs keep increasing.
• Technology remains constant.

Step 3: Check each option

• A. Increase in variable inputs: This is a cause. Adding more labour to a fixed piece of land crowds the fixed factor, so each extra worker adds less.
• B. Land fragmentation: This is a cause. Land split into tiny plots limits efficient use of the fixed factor, so extra inputs yield less.
• C. Constant technology: This is also a condition for diminishing returns. If technology does not improve, the extra inputs run into the limit of the fixed factor.
• D. Technological innovations: This is not a cause. Better technology (improved seeds, machinery, methods) raises productivity and shifts the production curve upward, which delays or offsets diminishing returns.

Step 4: Answer Technological innovations work against diminishing returns, so they are not a cause of it.

Answer: D

Exam tip: Remember the law as "ceteris paribus": one fixed factor and constant technology. If an option changes technology, it is breaking the law's assumption, so it is usually the "not a cause" answer.