This presentation is the property of its rightful owner.
1 / 50

# Output and Costs PowerPoint PPT Presentation

ECONOMICS 5e. Michael Parkin. Output and Costs. Learning Objectives. Distinguish between the short-run and the long-run Explain the relationship between a firm’s output and labor employed in the short-run Explain the relationship between a firm’s output and costs in the short-run

Output and Costs

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

ECONOMICS 5e

Michael Parkin

Output and Costs

### Learning Objectives

• Distinguish between the short-run and the long-run

• Explain the relationship between a firm’s output and labor employed in the short-run

• Explain the relationship between a firm’s output and costs in the short-run

• Derive and explain a firm’s short-run cost curves

### Learning Objectives (cont.)

• Explain the relationship between a firm’s output and costs in the long-run

• Derive and explain a firm’s long-run average cost curve

### Learning Objectives

• Distinguish between the short-run and the long-run

• Explain the relationship between a firm’s output and labor employed in the short-run

• Explain the relationship between a firm’s output and costs in the short-run

• Derive and explain a firm’s short-run cost curves

### Sidney’s Sweaters Inc.

Throughout the chapter we are going to refer to Sidney’s Sweaters Inc., a producer of knitted sweaters. The firm is owned and operated by Sidney.

### Decision Time Frames

The Objective: Profit Maximization

• All of the firm’s decisions are aimed at one overriding objective: maximum attainable profit.

To study the relationship between a firm’s output decision and its costs, we distinguish two decision time frames:

• The short-run

• The long-run

### Decision Time Frames

The Short-Run and the Long-Run

The short-run is a time frame in which the quantity of at least one input is fixed and the quantities of the other inputs can be varied.

The long-run is a time frame in which the quantities of all inputs can be varied.

A sunk cost is irrelevant to the firm’s decisions.

### Decision Time Frames

To increase output in the short-run, a firm must increase the quantity of labor employed.

Total product is the total output produced.

Marginal product is the increase in total product that result from a one-unit increase in an input.

Average product is the total product divided by the quantity of inputs.

### Learning Objectives

• Distinguish between the short-run and the long-run

• Explain the relationship between a firm’s output and labor employed in the short-run

• Explain the relationship between a firm’s output and costs in the short-run

• Derive and explain a firm’s short-run cost curves

### Total Product, Marginal Product, and Average Product

TotalMarginalAverage

Laborproduct product product

(workers(sweaters (sweaters per (sweaters

per day)per day) additional worker) per worker)

a 0 0

b 1 4

c 2 10

d 3 13

e 4 15

f 5 16

### Total Product, Marginal Product, and Average Product

TotalMarginalAverage

Laborproduct product product

(workers(sweaters (sweaters per (sweaters

per day)per day) additional worker) per worker)

a 0 0

b 1 4

c 2 10

d 3 13

e 4 15

f 5 16

4

6

3

2

1

### Total Product, Marginal Product, and Average Product

TotalMarginalAverage

Laborproduct product product

(workers(sweaters (sweaters per (sweaters

per day)per day) additional worker) per worker)

a 0 0

b 1 4 4.00

c 2 10 5.00

d 3 13 4.33

e 4 15 3.75

f 5 16 3.20

4

6

3

2

1

TP

f

e

d

c

b

a

### Total Product Curve

15

Unattainable

Output (sweaters per day)

10

Attainable

5

0 1 2 3 4 5

Labor (workers per day)

### Marginal Product Curve

Marginal product is also measured by the slope of the total product curve.

Increasing marginal returns occur when the marginal product of an additional worker exceeds the marginal product of the previous worker.

### Marginal Product Curve

Diminishing marginal returns

Occur when the marginal product of an additional worker is less than the marginal product of the previous worker

Law of diminishing returns

As a firm uses more of a variable input, with a given quantity of fixed inputs, the marginal product of the variable input eventually diminishes

### Marginal Product

TP

15

6

d

13

Output (sweaters per day)

Marginal product

(sweaters per day per worker)

4

10

c

3

5

2

4

MP

0 1 23 4 5

0 1 23 4 5

Labor (workers per day)

Labor (workers per day)

### Average Product Curve

What does the average product curve look like?

Maximum

average

product

c

c

d

e

b

f

AP

MP

### Average Product

6

Average product & Marginal product

(sweaters per day per worker)

4.33

4

3

2

0 1 2 3 4 5

Labor (workers per day)

### Learning Objectives

• Distinguish between the short-run and the long-run

• Explain the relationship between a firm’s output and labor employed in the short-run

• Explain the relationship between a firm’s output and costs in the short-run

• Derive and explain a firm’s short-run cost curves

### Short-Run Cost

Total cost (TC) is the cost of all productive resources used by a firm.

Total fixed cost (TFC) is the cost of all the firm’s fixed inputs.

Total variable cost (TVC) is the cost of all the firm’s variable inputs.

### Short-Run Cost

Total cost (TC) is the cost of all productive resources used by a firm.

TC = TFC + TVC

### Total Cost Curves

Total Total

fixed variable Total

cost cost cost

Labor Output(TFC)(TVC) (TC)

(workers (sweaters

per day) per day) (dollars per day)

a 0 0

b 1 4

c 2 10

d 3 13

e 4 15

f 5 16

### Total Cost Curves

Total Total

fixed variable Total

cost cost cost

Labor Output(TFC)(TVC) (TC)

(workers (sweaters

per day) per day) (dollars per day)

a 0 0 25

b 1 4 25

c 2 10 25

d 3 13 25

e 4 15 25

f 5 16 25

### Total Cost Curves

Total Total

fixed variable Total

cost cost cost

Labor Output(TFC)(TVC) (TC)

(workers (sweaters

per day) per day) (dollars per day)

a 0 0 25 0

b 1 4 25 25

c 2 10 25 50

d 3 13 25 75

e 4 15 25 100

f 5 16 25 125

### Total Cost Curves

Total Total

fixed variable Total

cost cost cost

Labor Output(TFC)(TVC) (TC)

(workers (sweaters

per day) per day) (dollars per day)

a 0 0 25 0 25

b 1 4 25 25 50

c 2 10 25 50 75

d 3 13 25 75 100

e 4 15 25 100 125

f 5 16 25 125 150

TC

TVC

TFC

### Total Cost Curves

TC = TFC + TVC

150

Cost (dollars per day)

100

50

0 5 10 15

Output (sweaters per day)

### Marginal Cost

Marginal cost is the increase in total cost that results from a one-unit increase in output.

It equals the increase in total cost divided by the increase in output.

Marginal costs decrease at low outputs because of the gains from specialization, but it eventually increases due to the law of diminishing returns.

### Average Cost

Average fixed cost (AFC) is total fixed cost per unit of output.

Average variable cost (AVC) is total variable cost per unit of output.

Average total cost (ATC) is total cost per unit of output.

TC TFC TVC

=

+

Q Q Q

TC = TFC + TVC

OR

ATC = AFC + AVC

### Marginal Cost and Average Costs

Total Total Average Average

fixed fixed TotalMarginal fixed variable Total

cost cost cost cost cost cost cost

Labor Output (TFC) (TVC) (TC) (MC) (AFC) (AVC) (ATC)

(workers (sweaters (dollars per

per day) per day) (dollars per day) additional sweater)(dollars per sweater)

a 0025 0 25

b1 4252550

c210255075

d3132575100

e41525100125

f51625125150

### Marginal Cost and Average Costs

TotalTotal Average Average

fixedfixedTotalMarginal fixed variable Total

costcost cost cost cost cost cost

Labor Output (TFC) (TVC)(TC) (MC) (AFC) (AVC) (ATC)

(workers (sweaters (dollars per

per day) per day) (dollars per day) additional sweater)(dollars per sweater)

0

1

2

3

4

5

0

25

50

75

100

125

a

b

c

d

e

f

0

4

10

13

15

16

25

25

25

25

25

25

25

50

75

100

125

150

6.25

4.17

8.33

12.50

25.00

0

1

2

3

4

5

0

25

50

75

100

125

6.25

2.50

1.92

1.67

1.56

a

b

c

d

e

f

0

4

10

13

15

16

25

25

25

25

25

25

25

50

75

100

125

150

6.25

4.17

8.33

12.50

25.00

### Marginal Cost and Average Costs

TotalTotal Average Average

fixedfixedTotalMarginal fixed variable Total

costcost cost cost cost cost cost

Labor Output (TFC) (TVC) (TC) (MC) (AFC) (AVC) (ATC)

(workers (sweaters (dollars per

per day) per day) (dollars per day) additional sweater)(dollars per sweater)

### Marginal Cost and Average Costs

TotalTotal Average Average

fixedfixedTotalMarginal fixed variable Total

costcost cost cost cost cost cost

Labor Output (TFC) (TVC) (TC) (MC) (AFC) (AVC) (ATC)

(workers (sweaters (dollars per

per day) per day) (dollars per day) additional sweater)(dollars per sweater)

0

1

2

3

4

5

0

25

50

75

100

125

6.25

2.50

1.92

1.67

1.56

a

b

c

d

e

f

0

4

10

13

15

16

6.25

5.00

5.77

6.77

7.81

25

25

25

25

25

25

25

50

75

100

125

150

6.25

4.17

8.33

12.50

25.00

### Marginal Cost and Average Costs

TotalTotal Average Average

fixedfixedTotalMarginal fixed variable Total

costcost cost cost cost cost cost

Labor Output (TFC) (TVC) (TC) (MC) (AFC) (AVC) (ATC)

(workers (sweaters (dollars per

per day) per day) (dollars per day) additional sweater)(dollars per sweater)

0

1

2

3

4

5

0

25

50

75

100

125

6.25

2.50

1.92

1.67

1.56

a

b

c

d

e

f

0

4

10

13

15

16

6.25

5.00

5.77

6.77

7.81

25

25

25

25

25

25

25

50

75

100

125

150

12.50

7.50

7.69

8.33

9.38

6.25

4.17

8.33

12.50

25.00

MC

ATC

AVC

AFC

### Marginal Cost and Average Costs

ATC = AFC + AVC

15

Cost (dollars per sweater)

10

5

0 5 10 15

Output (sweaters per day)

### Cost Curves and Product Curve

How are the product curves related to the cost curves?

AP

MP

### Product Curvesand Cost Curves

6

4

Average product and marginal product

2

2

Rising MP and

falling MC:

rising AP and

falling AVC

Falling MP and

rising MC:

rising AP and

falling AVC

Falling MP and

rising MC:

falling AP and

rising AVC

01.52.0

Labor

MC

AVC

Maximum MP and

minimum MC

Maximum AP and

minimum AVC

### Product Curvesand Cost Curves

12

9

Average product and marginal product

6

3

0 6.5 10

Labor

### Learning Objectives (cont.)

• Explain the relationship between a firm’s output and costs in the long run

• Derive and explain a firm’s long-run average cost curve

### Long-Run Cost

Long-run cost

• The cost of production when a firm uses the economically efficient quantities of labor and capital.

Long-run costs are affected by the production function.

Production function

• The relationship between the maximum output attainable and the quantities of both labor an capital.

### Learning Objectives (cont.)

• Explain the relationship between a firm’s output and costs in the long run

• Derive and explain a firm’s long-run average cost curve

### The Production Function

Output (sweaters per day)

LaborPlant 1 Plant 2 Plant 3 Plant 4

1 4 10 13 15

2 10 15 18 21

3 13 18 22 24

4 15 20 24 26

5 16 21 25 27

Knitting machines (number) 1 2 3 4

### The Long-Run Average Cost Curve

The long-run average total cost curve is derived from the short-run average total cost curves.

The segment of the short-run average total cost curves along which average total cost is the lowest make up the long-run average total cost curve.

### Returns to Scale

Returns to scale are the increases in output that result from increasing all inputs by the same percentage.

Three possibilities:

• Constant returns to scale

• Increasing returns to scale

• Decreasing returns to scale

### Returns to Scale

Constant returns to scale

Technological conditions under which a given percentage increase in all the firm’s inputs results in the firm’s output increasing by thesamepercentage

### Returns to Scale

Increasing returns to scale

Technological conditions under which a given percentage increase in all the firm’s inputs results in the firm’s output increasing by a larger percentage

### Returns to Scale

Decreasing returns to scale

Technological conditions under which a given percentage increase in all the firm’s inputs results in the firm’s output increasing by a smaller percentage

### Minimum Efficient Scale

A firm’s minimum efficient scale is the smallest quantity of output at which long-run average cost reaches its lowest level.