Introduction
to Economics ECO401
VU
Lesson
5.3
BACKGROUND
TO SUPPLY/COSTS
(CONTINUED..............)
Isoquant:
An
isoquant represents different
combinations of factors of production
that a firm can
employ
to
produce the same level of
output.
Isoquants
can be used to illustrate
the concepts of returns to
scale and returns to
factor.
Isoquant
Map:
Like
an indifference map, an isoquant
map consists of parallel
isoquants that do not
intersect.
The
higher the output level
the further to the right an
isoquant will be.
Marginal
Rate of Technical Substitution
(MRTS):
The
slope of an isoquant is called
marginal rate of technical
substitution (MRTS). It is
analogous
to the term marginal rate of
substitution (MRS) in consumer
analysis. MRTS is the
amount
of one factor, e.g. capital,
that can be replaced by a 1
unit increase in the other
factor
e.g.
labor, if output is to be held
constant.
The
principle of diminishing MRTS is
related to the law of
diminishing returns. As one
moves
down
along an isoquant drawn in
K-L space, increasing
amounts of labor are used
relative to
capital.
Now, given diminishing
returns, the MPP of labor
will fall relative to the
MPP of capital.
Isoquants
can be used to illustrate
the concepts of returns to
scale and returns
to
factor.
a.
Constant returns to scale:
equally spaced
isoquants;
b.
Increasing returns to scale:
isoquants become closer and
closer to each other;
c.
Decreasing returns to scale:
isoquants become further and
further apart from
each
other.
Diminishing
returns to factors can be
illustrated by keeping one of
the inputs constant
(say
capital).
Here if there are constant
returns to scale, ever
increasing increments of labor
will be
required
to produce equal increments to
output.
Budget
Line:
The
concept of isocost is similar to
the budget line developed in
indifference curve analysis.
It
is
a line which captures all
the different combinations of
inputs that the firm
can afford to hire.
a.
If price of both inputs
increases, the isocost line
shifts inwards.
b.
If price of one input
increases, it pivots
out.
c.
The slope of isocost is
PL/PK.
The
isoquant-isocost combination can
help answer:
a.
What is the least cost
way of producing a particular
level of output?
b.
What the highest level of
output the firm can
produce given a certain
budget.
In
either case, the
optimal factor combination
obtains
at the point of tangency
between the
relevant
iso-cost and
iso-quant.
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