Saturday, June 7, 2008

COST AND OUTPUT : PART TWO

RELATED CONCEPTS:|ACCOUNTING PROFIT |AVERAGE VARIABLE, FIXED, AND TOTAL COSTS |CONSTANT RETURN TO SCALE |DISECONOMIES OF SCALE |ECONOMIC PROFIT |ECONOMIES OF SCALE |EXPLICIT COSTS |IMPLICIT COSTS |LAW OF DIMINISHING MARGINAL RETURNS |LONG AND SHORT RUN |LONG-RUN AVEAGE COST|MARGINAL COST |MARGINAL PHYSICAL PRODUCT |TOTAL COST |TOTAL FIXED COSTS |TOTAL VARIABLE COSTS |.


If one added worker increases output by ten units, how much labor is embodied in each unit of output? If the added worker costs $120,000, what is the marginal cost of one extra unit of output?

  • One-tenth of a worker is embodied in each unit of output. So each unit costs one-tenth of $12,000, or $1,200.


Answer true or false:

a. ATC falls only when MC falls.

b. At the minimum AVC, AVC = MC

c. ATC falls when MC

d. TC increases by MC.


a. False.

b. True.

c. True.

d. True.


Mary Jones can work in a factory and earn $16,000 a year, or alternatively, be a farmer. Assume that except for monetary reward, she doesn’t care which she does. To farm, Mary has to invest her savings of $20,000. The annual cost of seed, fertilizer, etc., is $5,000. She could earn 10% annually on her best alternative investment.

a. What is the total cost of farming (including implicit costs)?

b. What is the minimum Mary must make in farming to just make it worthwhile?

c. If her farm revenues ar $30,000, what is her economic profit? Her accounting profit? Should she stay in farming?

d. Answer (c) above for revenues of $20,000


a. $23,000: Explicit costs are $5,000. Implicit costs include her forgone earnings of 416,000 plus the forgone interest of $2,000 she could have earned had she invested the $20,000 of savings at 10%.

b. $23,000

c. Economic profit = - $7,000. Accounting profit = $25,000. She should farm.

d. Economic profit = - $3,000 (i.e., a $3,000 loss). Accounting profit = $15,000. She should not farm.


Old Fud owns a jewelry store. He didn’t raise his prices on the diamonds he bought last year even though diamond prices have since doubled. He says: “I’m still making a profit at my old price.” Is Old Fud right?

  • Old Fud is wrong. He is ignoring the higher opportunity costs of diamonds.


Between two towns, one can (a) fly at a cost of $100 taking one hour, or (b) take a bus at $50, which takes five hours. Why are business men and women more likely to choose (a) while relatively more students will choose (b)?

  • Businessmen and women usually have a higher opportunity cost of time than students and so are more likely to find flying cheaper. For example, if the opportunity cost of time is $20 an hour, the plane’s cost is $120 while the bus’s cost is $150.


Consider the cost curves of a trucking firm.

a. Suppose there is an increase in the price of gasoline. How will each of these cost curves shift up (if they shift at all): MC, ATC, AVC, AFC?

b. Suppose the cost of incorporating and setting up a trucking business goes up. How will each of the above cost curves shift?


a. MC, AVC, and ATC will shift up. AFC will be unchanged.

b. AFC and ATC will shift up. MC and AVC will be unchanged.


Suppose a firm’s production process can be characterized as having economies of scale. If so, when output doubles, what happens to total cost? To ATC?

  • Total costs will less than double, such that ATC falls.


Copyright 2008 by Sujanto Rusli
http://economicslessons.blogspot.com
http://become-debt-free.blogspot.com
http://humorandwit.blogspot.com

COST AND OUTPUT : PART ONE

RELATED CONCEPTS:|ACCOUNTING PROFIT |AVERAGE VARIABLE, FIXED, AND TOTAL COSTS |CONSTANT RETURN TO SCALE |DISECONOMIES OF SCALE |ECONOMIC PROFIT |ECONOMIES OF SCALE |EXPLICIT COSTS |IMPLICIT COSTS |LAW OF DIMINISHING MARGINAL RETURNS |LONG AND SHORT RUN |LONG-RUN AVEAGE COST|MARGINAL COST |MARGINAL PHYSICAL PRODUCT |TOTAL COST |TOTAL FIXED COSTS |TOTAL VARIABLE COSTS |.


Why are average costs lowest in the long run?

  • Because the firm can then select the scale of plant and the amount of equipment that is most efficient for each level of output.


What is happening to the marginal productivity of workers as marginal costs fall?

  • MPP is increasing, meaning it takes less labor units to produce each unit of output.


Why do marginal costs rise?

  • Because MPP increases due to the law of diminishing marginal returns, each added unit of output requires more labor units to produce and so, a higher marginal cost.


Is the law of diminishing marginal returns true when all inputs are increased together?

  • No. It holds true only when some inputs are not increased.


How is the total variable cost curve derived from the marginal cost curve?

  • TVC is the sum of the MCs.


How is the total cost curve derived from the total variable cost curve?

  • TC is derived by adding fixed costs to TVC.


When MC less than AVC, how will AVC change when output is increased?

  • AVC will fall.

How is MC related to AVC and ATC at their respective minimum values?

  • MC = AVC at AVC’s minimum. MC = ATC at ATC’s minimum.

Why does the ATC fall when the firm is experiencing economies of scale?

  • ATC falls since each added unit of output costs less since less added inputs are needed to produce it.

Why would a firm be better off not producing when its economics profits are negative?

  • Because then it would be better off investing its time and capital elsewhere. Total costs equal the opportunity cost (i.e., the forgone revenues) of the best alternative. If the firm earns less, it’s better off with the alternative.

Copyright 2008 by Sujanto Rusli
http://economicslessons.blogspot.com
http://become-debt-free.blogspot.com

http://humorandwit.blogspot.com