The MRTS for isoquants in a fixed-proportion production function is:
A) zero or one.
B) always zero.
C) always one.
D) zero or undefined.

Question

Quizplus · Accepted Answer

In a fixed-proportion production function, inputs must be used in a fixed ratio to produce output. If you try to change the ratio of inputs, production cannot increase because the inputs are complements in fixed proportions. Therefore, the marginal rate of technical substitution (MRTS), which measures the rate at which one input can be substituted for another while keeping output constant, is either zero (if you're trying to substitute more of one input for another but can't because of the fixed ratio) or undefined (if you're at a point where you cannot substitute at all because you're exactly at the fixed ratio and any change would disrupt production).

The MRTS for Isoquants in a Fixed-Proportion Production Function Is