Law of Variable proportions is applicable in __________.

Short run

The correct answer is option 1: Short run

The Law of Variable Proportions states that when one input (e.g., labor) is increased while keeping other inputs (e.g., capital, land) fixed, the marginal product of the variable input first increases, then decreases, and eventually becomes negative.

Why is it applicable in the short run?

• In the short run, at least one factor of production remains fixed.
• As more of the variable input (e.g., labor) is added, diminishing returns set in after a certain point.
• This law explains why increasing only one input while keeping others fixed eventually leads to lower productivity.

Why not the other options?

• Long Run (Option 2): In the long run, all factors of production are variable, so the Law of Variable Proportions does not apply. Instead, firms face returns to scale.
• Medium Run (Option 3): This is not a standard economic term.