- [Instructor] We've spent
a lot of time already
thinking about markets
for the goods and services
that firms produce.
Now we're gonna talk about
the markets or the factors
of production often known
as the factor markets.
What are those factors of production?
Well we've talked about
'em multiple times,
things like land, labor,
capital, and in particular,
we're going to focus
in this video on labor.
So what we have here is some
axis where the vertical axis
is labeled the wage rate, you
could do that as the price
of labor, it'd be per unit time,
and on the horizontal axis
in both of these cases,
we have the quantity of labor
which would be the number
of workers in that unit of time.
And what we're gonna do on
the right hand side right here
is think about it form the
point of view of a firm,
and then on the left hand side,
we're gonna think about it
from the point of view
of the market as a whole,
and to understand it first
on the firm's point of view,
we can think about the demand from a firm.
How much benefit is a firm getting
when it hires that incremental worker?
And to do that, we're
gonna think about something
called marginal revenue product.
Now marginal revenue
product sounds very fancy,
but I'm gonna set up a little table here
so that we can understand
in reasonable terms.
So let's say that this is our labor again,
so I'm gonna set up several columns here.
This is how much product
the firm can produce
based on the number of labor units.
Then you have the
marginal product of labor
which is for each
incremental unit of labor,
how much more are you able to produce?
So let me make some columns here,
and I'm going to add more
columns in a little bit.
So let's say we could
have zero units of labor,
one unit of labor, two units of labor.
When you have zero units, you're
definitely going to produce
zero units in that time period.
Let's say when you have one unit of labor,
one worker in the time period,
you're able to produce two.
When you have that second
labor, or that second worker,
you're now able to produce
six, and so we can think
about the marginal product of labor.
That first worker is able to
produce an incremental two,
we went from zero to two,
but that second worker,
by adding them, now you're able to produce
an incremental three units, and so here,
this might be due to
specialization, things like that,
but over time you might have diminishing
marginal products of labor,
but then if you want to think about
well what's the real benefit to the firm,
it's not just what is being produced
but how much the firm can get for that.
So we can think about
the marginal revenue,
and so let's just say that
that is, I don't know,
four dollars, and it's just
a constant four dollars,
and then we can think about
the marginal revenue product
which is just going to be
the marginal product of labor
times the amount of dollars
or incremental amount
of dollars per unit so it's just gonna be
two times four here which is
just going to be eight dollars.
So one way to think about
it, when the firm goes
from zero labors, or zero
workers, to one worker,
you're going to have an
incremental eight dollars
of revenue based on what
that worker can produce,
and then when you add another worker,
you get three times four,
you get an incremental
12 dollars of revenue.
And so we can graph this, and as I said,
sometimes you might say
initially you could get
some benefits of specialization,
but then over time you
get diminishing returns,
so it might look something like this.
Typically, in an econ class,
you'll just see a downward
sloping line for simplicity,
but the firm's marginal revenue product,
you can view it as that individual
firm's demand for labor.
At those first few units of labor,
it has a very high
marginal revenue product,
but over time you have diminishing returns
from adding more and more
people onto the staff.
Now how would this look at the market?
Well what you could do is you could add up
all the marginal revenue products
from all the firms in the market,
and if you add them
up, you're going to get
a market labor demand curve.
And let me do this in a
slight different color.
If you add all of these up,
you are going to get something like this.
Let me write that out.
That is the market market
labor demand demand curve.
Now what is going to be the
reasonable level of labor
quantity both in the market
and how much would be rational
for this firm to hire?
Well to think about that,
we think about the market
labor supply curve,
and I'm gonna focus on the market first,
and just like the market for most things,
the higher the wage,
you're going to have more folks
willing to participate
in that labor market.
So at a low wage, not a lot of people
are going to want to
work in this industry,
but as wages get higher and higher,
well then more and more
people are going to be up
for participating in this labor market,
and so this right over
here is the market labor
supply curve supply curve,
and so what would be the
equilibrium price of labor
which was really just the wage rate,
well it's where your supply
and demand curves intersect
and we've seen this
multiple times already.
So this is I'll just call
that wage star like that,
and then the equilibrium
quantity of labor,
we can just call that
Q star right over here.
Now how would that impact
what's going on in the firm?
Well if we assume that this
is a perfectly competitive
labor market, we'll assume that this firm
can't set the wage, it's just
going to have to pay people
whatever the equilibrium wage actually is,
and so this right over here
is going to be the firm's
what's known as marginal factor cost,
the cost per incremental unit of labor,
that's just the wage it's
going to have to pay.
It can get as much of that
labor as we need, we assume,
'cause we're talking about
a perfectly competitive
labor market in this industry,
I'm just trying to draw a straighter line.
So this right over here is
our marginal factor cost,
and so you can imagine what
is the rational quantity
for this firm to hire?
It would keep hiring all the way until
the incremental revenue
per unit of labor it gets
is no longer higher than the
incremental cost of that labor,
and that would happen right over here.
So this would tell us the
rational quantity of labor,
I'll call that quantity for,
I'll call it Q star for
the firm right over there.
I'll leave you there now.
The important thing to realize,
this seems similar to what
we've seen before when we talked
about things like marginal
revenue and marginal cost
for a firm's good, but
here we're talking about
a firm's inputs and so instead
of it being the marginal
revenue in the price in a
perfectly competitive firm
that is defined by the equilibrium price,
here it is the firm's cost that is defined
by the equilibrium wage in the market.
