Law of Diminishing Marginal Rate of Substitution and its Reasons

The article explains the concept of Law of Diminishing Marginal Rate of Substitution (MRS) and its formula to determine MRS's value. It also discusses the reasons why isoquant must be bent towards the origin and the restrictions on MRS. The article cites references from International Journal of Production Economics and European Journal of Operational Research.

Marginal Rate of
Substitution

Table of Contents
Elucidation of the concept law of diminishing Marginal Rate of Substitution (MRS)...................3
Enumeration of the reasons suggested by MRS, that isoquant must be bent toward the origin......4
REFERENCES..............................................................................................................................4

Elucidation of the concept law of diminishing Marginal Rate of Substitution
(MRS).
The quantity of a good that a customer is prepared to consume in comparison to another
good, provided that the new item is equally fulfilling, is known as the marginal rate of
substitution (MRS) in economics. The indifference theory uses MRS to examine customer
behaviour. Since they don't gain or lose any satisfaction from the exchange, people who are
indifferent to substitution have zero marginal value for substitution (Dormady and et. al., 2022).
When the law of diminishing MRS is in play, the MRS takes the shape of a convex, downward-
sloping curve that indicates more consumption of one good over another. The following formula
should be used to determine MRS's value:
∣MRSxy∣=dxdy=MUyMUx
x,y = two distinct items
MU = marginal utility of good x, y
where dxdy = derivative of y with respect to x
For the marginal rate of substitution assessment, it is crucial to know the inclination of
the indifference curve. MRS is essentially the indifference curve's slope at any given location on
the curve. The slopes will vary as one travels along the majority of indifference curves since they
bend. Typically, a customer will prefer the alternative over the other good but instead of
concurrently consuming more, which is known as diminishing marginal substitution.
There are several restrictions on the marginal rate of substitution. The fundamental flaw
is that it doesn't analyse whether a consumer would choose one combination of items over
another. This often restricts the MRS analysis to two variables. Additionally, MRS does not
always consider marginal utility because it regards the usefulness of two comparable
commodities identically, despite the possibility that their utility may vary.

Enumeration of the reasons suggested by MRS, that isoquant must be bent toward
the origin.
The origin of an isoquant should always be convex. This is as a result of how the
diminishing marginal rate of technical substitution works. The marginal rate of substituting a
fractional unit of one input for another while maintaining the same level of output is known as
the marginal rate of substituting (MRTS). The give-and-take between variables, such as labor
and capital, that enables a firm to maintain a steady output is reflected in the MRTS. Since
MRTS is centered on supplier 's equilibrium whereas MRS is concentrated on consumer
equilibrium, the two concepts differ from one another (Lee and Charles, 2022). It provides an
economic explanation of the threshold at which one input item must fall. Another production
factor is enhanced while the volume of production remains constant. It demonstrates how you
can swap out one input for another without changing the final output. For MRTS must decrease,
the isoquants have to be convex to the source.
REFERENCES
Books and Journals
Dormady, N.C., and et. al., 2022. The cost-effectiveness of economic resilience. International
Journal of Production Economics, 244, p.108371.
Lee, C.Y. and Charles, V., 2022. A robust capacity expansion integrating the perspectives of
marginal productivity and capacity regret. European Journal of Operational Research,
296(2), pp.557-569.