c ost of p roduction etp economics 101. f irm ’ s o bjective the firm ’ s objective the economic...
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T OTAL R EVENUE AND T OTAL C OST Total Revenue The amount a firm receives for the sale of its output. Total Cost The market value of the inputs a firm uses in production.TRANSCRIPT
COST OF PRODUCTIONETP Economics 101
FIRM’S OBJECTIVE The Firm’s Objective
The economic goal of the firm is to maximize profits.
TOTAL REVENUE AND TOTAL COST Total Revenue
The amount a firm receives for the sale of its output.
Total Cost The market value of the inputs a firm uses in
production.
PROFIT Profit is the firm’s total revenue minus its
total cost.
Profit = Total revenue - Total Profit = Total revenue - Total costcost
FIRM’S COST OF PRODUCTION A firm’s cost of production includes all the
opportunity costs of making its output of goods and services.
Explicit and Implicit Costs A firm’s cost of production include explicit
costs and implicit costs. Explicit costs are input costs that require a
direct outlay of money by the firm. Implicit costs are input costs that do not
require an outlay of money by the firm.
ECONOMIC PROFIT AND ACCOUNTING PROFIT Economists measure a firm’s economic profit as total
revenue minus total cost, including both explicit and implicit costs.
Accountants measure the accounting profit as the firm’s total revenue minus only the firm’s explicit costs.
When total revenue exceeds both explicit and implicit costs, the firm earns economic profit. Economic profit is smaller than accounting profit.
FIGURE 1 ECONOMIC VERSUS ACCOUNTANTS
Copyright © 2004 South-Western
Revenue
Totalopportunitycosts
How an EconomistViews a Firm
How an AccountantViews a
Firm
Revenue
Economicprofit
Implicitcosts
Explicitcosts
Explicitcosts
Accountingprofit
EXAMPLE: JOE RUNS A SMALL BOAT FACTORY Joe can make 10 boats/year and can sell
them for $25,000 each. It costs Joe $150,000 for raw materials. Joe Invests $400,000 in factory and
equipments: $200,000 from his own savings and $200,000 borrowed at 10% interest (assume Joe could have loaned his money out at 10% interest).
Joe can work at a competing boat factory for $70,000/year.
EXAMPLE: CONTINUED Total revenue=10*25,000=$250,000 Explicit costs =$150,000+
($200,000*0.1)=$170,000 Total opportunity costs=Explicit +Implicit
=[$150,000+($200,000*0.1)]+[($200,000*0.1)+$70,000]=$260,000
Accounting profit=$250,000-$170,000=$80,000
Economic profit=$250,000-$260,000=-$10,000
PRODUCTION FUNCTION The Production Function
The production function shows the relationship between quantity of inputs used to make a good and the quantity of output of that good.
Q= f(L, K), where L is labor and K is capital
MARGINAL PRODUCT Marginal Product
The marginal product of any input in the production process is the increase in output that arises from an additional unit of that input.
Diminishing Marginal Product Diminishing marginal product is the property
whereby the marginal product of an input declines as the quantity of the input increases. Example: As more and more workers (labors) are hired
at a firm, each additional worker contributes less and less to production because the firm has a limited amount of equipment (capital).
FIGURE 2 HUNGRY HELEN’S PRODUCTION FUNCTION
Copyright © 2004 South-Western
Quantity ofOutput
(cookiesper hour)
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
Number of Workers Hired0 1 2 3 4 5
Production function
SLOPE OF PRODUCTION FUNCTION Diminishing Marginal Product
The slope of the production function measures the marginal product of an input, such as a worker.
When the marginal product declines, the production function becomes flatter.
PRODUCTION FUNCTION AND TOTAL COST CURVE The relationship between the quantity a firm
can produce and its costs determines pricing decisions.
The total-cost curve shows this relationship graphically.
FIGURE 3 HUNGRY HELEN’S TOTAL-COST CURVE
Copyright © 2004 South-Western
TotalCost
$80
70
60
50
40
30
20
10
Quantityof Output
(cookies per hour)
0 10 20 30 15013011090705040 1401201008060
Total-costcurve
FIXED AND VARIABLE COSTS Costs of production may be divided into fixed
costs and variable costs. Fixed costsFixed costs are those costs that do not vary
with the quantity of output produced. Variable costsVariable costs are those costs that do vary
with the quantity of output produced.
FORMULA OF TOTAL COST Total Costs (TC)
Total Fixed Costs (TFC) Total Variable Costs (TVC) Total Costs (TC) TC = TFC + TVC
AVERAGE COSTS Average Costs
Average costs can be determined by dividing the firm’s costs by the quantity of output it produces.
The average cost is the cost of each typical unit of product.
Average Costs Average Fixed Costs (AFC) Average Variable Costs (AVC) Average Total Costs (ATC) ATC = AFC + AVC
AVERAGE COSTS
AFC FCQ
F ix ed co stQ u an tity
AVC VCQ
V ariab le co stQ u an tity
ATC TCQ
T o ta l co stQ u an tity
MARGINAL COSTS Marginal Cost
Marginal cost (MC) measures the increase in total cost that arises from an extra unit of production.
Marginal cost helps answer the following question: How much does it cost to produce an additional unit of
output?
FORMULA OF MARGINAL COST
M C TCQ
( ch an ge in to ta l co st)(ch an g e in q u an tity )
NOTE Marginal Cost
= Change in Total Cost/Change in Quantity
= Change in Variable Cost/Change in Quantity
CASE: THIRSTY THELMA’S LEMONADE STAND
FIGURE 5 THIRSTY THELMA’S AVERAGE-COST AND MARGINAL-COST CURVES
Copyright © 2004 South-Western
Costs
$3.50
3.25
3.00
2.75
2.50
2.25
2.00
1.75
1.50
1.25
1.00
0.75
0.50
0.25
Quantityof Output
(glasses of lemonade per hour)
0 1 432 765 98 10
MC
ATC
AVC
AFC
MARGINAL COST CURVE AND ITS SHAPE Marginal cost rises with the amount of output
produced. This reflects the property of diminishing marginal
product.
AVERAGE TOTAL COST CURVE AND ITS SHAPE The average total-costaverage total-cost curve is U-shaped. At very low levels of output average total cost is high
because fixed cost is spread over only a few units. Average total cost declines as output increases. Average total cost starts rising because average
variable cost rises substantially. The bottom of the U-shaped ATC curve occurs at the
quantity that minimizes average total cost. This quantity is sometimes called the efficient scale of the firm.
RELATIONSHIP BETWEEN MC AND ATC Relationship between Marginal Cost and
Average Total Cost Whenever marginal cost is less than average
total cost, average total cost is falling. Whenever marginal cost is greater than
average total cost, average total cost is rising. The marginal-cost curve crosses the average-
total-cost curve at the efficient scaleefficient scale. Efficient scale is the quantity that minimizes
average total cost.
TYPICAL COST CURVES
It is now time to examine the relationships that exist between the different
measures of cost.
FIGURE 6 BIG BOB’S COST CURVES
Copyright © 2004 South-Western
(a) Total-Cost Curve
$18.00
16.00
14.00
12.00
10.00
8.00
6.00
4.00
Quantity of Output (bagels per hour)
TC
42 6 8 141210
2.00
TotalCost
0
FIGURE 6 BIG BOB’S COST CURVES
Copyright © 2004 South-Western
(b) Marginal- and Average-Cost Curves
Quantity of Output (bagels per hour)
Costs
$3.00
2.50
2.00
1.50
1.00
0.50
0 42 6 8 141210
MC
ATCAVC
AFC
PROPERTIES OF TYPICAL COST CURVES Important Properties of Cost Curves
Marginal cost eventually rises with the quantity of output.
The average-total-cost curve is U-shaped. The marginal-cost curve crosses the average-
total-cost curve at the minimum of average total cost.
The marginal-cost curve crosses the average-variable cost curve at the minimum of average variable cost.
COSTS IN THE SHORT RUN AND IN THE LONG RUN For many firms, the division of total costs
between fixed and variable costs depends on the time horizon being considered. In the short run, some costs are fixed. In the long run, fixed costs become variable
costs.
SHORT-RUN COST CURVES AND LONG-RUN COST CURVES Because many costs are fixed in the short
run but variable in the long run, a firm’s long-run cost curves differ from its short-run cost curves.
FIGURE 7 AVERAGE TOTAL COST IN THE SHORT AND LONG RUN
Copyright © 2004 South-Western
Quantity ofCars per Day
0
AverageTotalCost
1,200
$12,000
ATC in shortrun with
small factory
ATC in shortrun with
medium factory
ATC in shortrun with
large factory
ATC in long run
ECONOMIES OF SCALE? Economies of scale refer to the property
whereby long-run average total cost falls as the quantity of output increases.
Diseconomies of scale refer to the property whereby long-run average total cost rises as the quantity of output increases.
Constant returns to scale refers to the property whereby long-run average total cost stays the same as the quantity of output increases
FIGURE 7 AVERAGE TOTAL COST IN THE SHORT AND LONG RUN
Copyright © 2004 South-Western
Quantity ofCars per Day
0
AverageTotalCost
1,200
$12,000
1,000
10,000
Economiesof
scale
ATC in shortrun with
small factory
ATC in shortrun with
medium factory
ATC in shortrun with
large factory ATC in long run
Diseconomiesof
scale
Constantreturns to
scale