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1. Chapter 6Production Day 1
2. Announcements
3. Next exam: 9 Nov
Last day to drop: 2 Nov
Homework question 2 was graded
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4. Course Roadmap
5. Production
Production Function
Q = F (M, L, K) where
M = materials
L = labor
K = capital
Examples
Q = 10 L – 0.5 L2 + 24 K – K2
Q = 12 L0.5K0.5M0.5 Definitions – Round 1 Production Ideas
6. Auto Parts Production Function
7. Auto Parts Production Function
8. Auto Parts Production Function
9. Short run
Fixed inputs
Long run
Variable input
Marginal product
Production function: Q = F (L, K, M)
Mathematical representation: ?Q / ?L = MPL
Example: Q = 10 L – 0.5 L2 + 24 K – K2
MPL = 10 – L
Example: Q = 12 L0.5K0.5M0.5
MPL = 6 L-0.5K0.5M0.5 = Definitions – Round 2 More Production Ideas
10. Auto Part Production Function
11. Total and Marginal Product(10,000 sq ft factory)
12. All inputs held constant except one
Law of diminishing marginal returns
Add successive units of the variable input
Eventually marginal product will decline
Can marginal product be negative?
What then? Law of Diminishing Marginal Returns
13. Free eucalyptus leaves
14. Definitions
Marginal revenue product (MRP) of a single input
MRPL, MRPK, MRPM
MRPL = (MR) (MPL)
Marginal cost of a single input (MCL)
Marginal profit per worker (M?L)
M?L = MRPL – MCL Definitions – Round 3 Purchasing Inputs
15. To decide how much labor to use
Set M?L = 0
M?L= MRPL – MCL= 0
MRPL = MCL
Solve for L Decision Rule
16. Information given
Production function: Q = 60 L – L2
Price of output = $2
MCL = $16 per hour
The problem
How much labor to hire?
How much output to produce? Example (Example 2, p 223)
17. Step 1: Decision rule
MRPL = MCL
Step 2: Calculate MRPL
Define MRPL= (MPL) (MR)
Define MPL = dQ / dL
Given: Q = 60 L – L2
MPL = 60 – 2 L
Given: MR = $2
MRPL = 2 (60 – 2L) = 4 (30 – L) Solution
18. Step 3: Find MCL
MCL= $16 per hour
Step 4: Use decision rule to solve for L
MRPL = MCL
4 (30 – L) = 16
30 – L = 4
L = 30 – 4 = 26
Hire 26 labor-hours Solution (continued)
19. Step 5: Find output level for L = 26
Q = 60 L – L2
Q = 60 (26) – (26)2
Q = 1,560 – 676
Q = 884 Solution (continued)
20. Step 0: identify information given and state objectives
Step 1: state the decision rule
Step 2: calculate MRPL
Step 3: find MCL
Step 4: use decision rule and solve for L
Step 5: find Q using output from Step 4 Solution Recap
21. Next exam: 9 November
Last day to drop: 2 November
Next homework: available 30 October, due 6 November
Exam 2 appeals are due Friday, October 30
Etiquette Dinner is 12 November at the SAC
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60 – 80% of jobs are found through networking
Speak with business executives at your table
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Announcements
22. Production and Costs Overview
23. Production and Costs Overview
24. In the short run
with K as the fixed input and
L as the variable input,
the firm maximizes profit
by operating where
MRPL = MCL Recap from Last Time
25. All inputs are variable
Two decisions:
Decide on input mix (capital – labor trade offs)
Decide on scale of operations
Definition: Returns to scale
Constant
Increasing
Decreasing
Definition: Output elasticity Long-Run Production Issues
26. Returns to Scale in Auto Parts
27. Q = 10 L – 0.5 L2 + 24 K – K2
Double the amount of labor and capital to see whether output doubles
K = 1, L = 2
Q = 10 (2) – 0.5 (2) (2) + 24 (1) – (1) (1)
Q = 20 – 2 + 24 – 1 = 41
K = 2, L = 4
Q = 10 (4) – 0.5 (4) (4) + 24 (2) – (2) (2)
Q = 40 – 8 + 48 – 4 = 76
Decreasing returns to scale Returns to Scale
28. Total cost with two inputs, L and K
TC = PL L + PK K
Decision rule
Long run
Least-cost combination of inputs
What if ?
What if Least Cost Production
29. Given
Q = 40 L – L2 + 54 K – 1.5 K2
PL = $10 PK = $15
Problem: Find the least-cost combination of L and K
Decision rule
MPL / PL = MPK / PK
Find MPL and MPK
MPL = 40 – 2L MPK = 54 – 3 K Example 3(page 227 - 8)
30. Use decision rule
(40 – 2 L) / 10 = (54 – 3 K) / 15
15 (40 – 2 L) = 10 (54 – 3 K)
30 (20 – L) = 30 (18 – K)
20 – L = 18 – K
L = K + 2 Example 3(continued)
31. Many combinations of L and K satisfy the condition.
Assume: L = 17, K = 15
Find Q and TC
Q = 40 L – L2 + 54 K – 1.5 K2
Q = 40 (17) – (17)2 + 54 (15) – 1.5 (15)2
Q = 680 – 289 + 810 – 1.5 (225)
Q = 1201 – 337.5
Q = 863.5
TC = PL L + PK K = 10 (17) + 15 (15)
TC = $395 Example 3(continued)
32. Definition
An isoquant is a curve that shows the different combinations of inputs a firm can use to produce a given level of output.
Production trade-offs: home construction
Earth moving: Bobcat, Caterpillar, or 10 shovels?
Electric nail gun or hammer?
Preview: The answer depends on the prices of the inputs Isoquants – Production Graphs
33. Contour Maps: Equal Elevations
34. One Isoquant
35. One Isoquant
36. Given: PK , PL and Total Cost (TC)
Find the combinations of L and K consistent with a given level of total cost.
TC = PK K + PL L
If all TC is spent on capital, the company can buy TC / PK units of capital.
If all TC is spent on labor, the company can buyTC / PL units of labor.
Slope of the isocost line is negative and equal to
– (TC / PK) / (TC / PL) = – (PL / PK) Isocost Line
37. Isocost Lines
38. Isocost Lines
39. Isocost Assumptions
PK = 10 PL = 10
Least-cost production occurs where the isocost is tangent to the isoquant.
Higher cost production is possible if sub-optimal combinations of L and K are chosen. Least-Cost Production
40. If input prices change, the slope of the isocost changes and the optimal combination of K and L changes
Use more of the relatively cheaper input Least-Cost Production
41. Idea: operate where the isoquant is tangent to the isocost curve
Slope of the isoquant
MTRS = MPL / MPK
Slope of the isocost
PL / PK
Decision rule
The Idea of Least-Cost Analysis
42. Sleeping > Talking
43. Linear Q = a + b L + c K
Marginal product is constant
Returns to scale depend on relative sizes of b and c and the sign of a.
Fixed Proportions
One crane, one crane operator
One hot dog, one bun
One left shoe, one right shoe
L-shaped isoquant
Marginal product is undefined
Constant returns to scale Types of Production Functions
44. Polynomial functions' properties depend on the equation
Q = a L K – b L2 K2 a > 0, b > 0
Marginal products decline
Decreasing returns to scale
Q = a1 L K + a2 L2K + a3 L K2 – a4 L3 K – a5 L K3
where all coefficients are positive
Marginal product increases then decreases
Increasing returns to scale at low output levels and decreasing returns at higher output levels Types of Production Functions (continued)
45. Cobb-Douglas Function
Q = c La Kß
Diminishing marginal returns to each input
Returns to scale depend on a + ß
If a + ß > 1, increasing returns to scale
If a + ß = 1, constant returns to scale
If a + ß < 1, decreasing returns to scale
Estimate it in its logarithmic form:
Log (Q) = log (c) + a log (L) + ß log (K) Types of Production Functions (continued)
46. Characteristics of Production Functions
47. Several data sources
Engineering data and experience
Speculative for new products or technologies
Does not incorporate non-production inputs
Time-series data from the company
Assumes process remains constant over time
Cross-sectional data from many plants or companies
Data on multiple plants for a single company is more likely to be available than across competitors Estimating a Production Function
48. MRPL = MCL
Short-run condition – only one variable input
Given production function (or MPL), MR, and MCL
Problem: Optimal amount of labor to employ?
How much output?
MPL / PL = MPK / PK = MPM / PM …
Long-run condition – all inputs variable
Given production function and input prices
Problem: How much of each input?
How much output? What is total cost? Review: Two Decision Rules for Inputs
49. Scenario
Short run; one variable input with limited supply
Two plants (A and B) with different production conditions
Production functions for each are given
Problem
Allocate the variable input between plants
Decision Rule: Allocate input until
MPA = MPB Special Case: Multiple Plants
50. Scenario
Short run; one variable input in limited supply
Two products (G, F) with different profitability
Problem
Allocate the limited variable input between products
Decision Rule
Allocate the input until
M?G = M?F Special Case: Alternative Products
51. Short-run: increase use of variable input until MCL = MRPL
With multiple variable inputs, allocate the inputs so the marginal product per dollar spent is equal across all inputs.
MPL / PL = MPK / PK = MPM / PM
With multiple plants for a given output, equalize marginal products across plants.
With multiple outputs, equalize marginal profits across outputs. Chapter 6: Decision-Making Principles