In: Economics
Paco's Painting Service does interior and exterior house
painting. They have a production function that uses three factors:
brushes (B), paint (P), and labor (L). In the short run, Paco's has
already committed to orders of brushes and paint, but can adjust
the number of hours of labor they use from week to week. Therefore,
their short-run production function depends only on labor and is
given by ?(?)=√L/2 , which implies that Paco's marginal product of
labor is ???=1/4√L
In the questions below, give all numerical answers to two decimal
places.
a) Suppose that Paco charges $4000 for a paint
job and that the current wage he must pay his workers is $28 per
hour.
How many worker hours should Paco use to maximize his profit?
________
How many painting jobs will Paco complete using this number of
worker hours? ________
In addition to hiring workers, Paco spends $150 on brushes (50
brushes at $3 each) and $3000 on paint (100 gallons at $30 per
gallon). What is Paco's profit using these values for his three
factors (labor, brushes, and paint)? $_______
b) Now suppose that Paco is able to negotiate a lower price for paint and can buy the 100 gallons he needs for $27 instead of $30. Due to this cost savings, Paco's profit-maximizing choice of labor will __________(increase/decrease/stay the same) and he will use ________ worker hours. He will complete ________ projects (houses painted) and earn a profit of $_________
Solution :-
(A) :-
short-run production function depends only on labor and is given by :-
?(?)=√L/2
Paco's marginal product of labor is :-
???=1/4√L
Supposing that Paco charges = $4000 for a paint job .
The current wage he must pay his workers is = $28 per hour.
Optimal number of worker hires at following point :-
MPL = w/p
Where, w = wage paid to workers
p = price charges for print job
MPL = w/p
1/4 √L = 28/4000
4000 = 28 x 4√L
√L = 4000/( 28 x 4)
√L = 1000/28
L = ( 1000/28)^2
[ L = 1275.51 ]
Worker hours should Paco use to maximize his profit is = 1275.51
q = √L/2
q = ( 1000/28)/2
q = 1000/(28 x 2)
q = 500/ 28
[q = 17.85 ]
Painting jobs Paco complete using number of worker hours is 17.85
In addition to hiring workers,
Paco spends $150 on brushes (50 brushes at $3 each) and
$3000 on paint (100 gallons at $30 per gallon).
Total Cost (TC) = labour cost + brushes + paint
= wL + 150 + 3000
= 28 x 1275.51 + 150 + 3000
= 35714.28 + 150 + 3000
[TC = 38864.28 ]
Total Revenue (TR ) = Price x quantity
= 4000 x 17.85
[ TR = 71400 ]
Profit = TR - TC
= 71400 - 38864.28
[ Profit = 32535.72 ]
So, Paco's profit is = $32535.72
(B) :-
Now suppose that Paco is able to negotiate a lower price for paint and can buy the 100 gallons he needs for $27 instead of $30.
Optimal number of worker hires at following point :-
MPL = w/p
1/4 √L = 28/4000
L = (1000/28)^2
[ L = 1275.51]
q = √L/2
= 1000/(28 x 2)
[q = 17.85 ]
Now, paint price gets lower from $30 to $27
Paco can buy paint = 100 gallons
Paint cost = 27 x 100
= 2700
TC = labour cost + brushes + paint
= wL + 150 + 2700
= 28 x 1275.51 + 150 + 2700
= 35714.28 + 150 + 2700
[TC = 38564.28 ]
TR = Price x quantity
= 4000 x 17.85
[TR = 71400 ]
Profit = TR - TC
= 71400 - 38564.28
[Profit = 32835.72 ]
Due to cost savings, Paco's profit-maximizing choice of labor will stay the same and
he will use 1275.51 worker hours.
He will complete 17.85 projects (houses painted) and earn a profit of $32835.72.