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Page 1: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

JDEP 384H: Numerical Methods in Business

Instructor: Thomas ShoresDepartment of Mathematics

Lecture 27, April 24, 2007110 Kaufmann Center

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 2: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

Outline

1 NT: Decision Analysis and Game TheoryAn Intelligent Opponent: Game TheoryAn Indi�erent Opponent: NatureDecision Making with Experimentation

2 Odds and Ends

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 3: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

An Intelligent Opponent: Game TheoryAn Indi�erent Opponent: NatureDecision Making with Experimentation

Outline

1 NT: Decision Analysis and Game TheoryAn Intelligent Opponent: Game TheoryAn Indi�erent Opponent: NatureDecision Making with Experimentation

2 Odds and Ends

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 4: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

An Intelligent Opponent: Game TheoryAn Indi�erent Opponent: NatureDecision Making with Experimentation

Outline

1 NT: Decision Analysis and Game TheoryAn Intelligent Opponent: Game TheoryAn Indi�erent Opponent: NatureDecision Making with Experimentation

2 Odds and Ends

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 5: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

An Intelligent Opponent: Game TheoryAn Indi�erent Opponent: NatureDecision Making with Experimentation

Sidebar: Grades and Final

What's the Score?

The grade lines are

A: 87%, B: 76%, C: 60%I will use this for both homework and midterm.Final Exam scale will be similar.

And what about the �nal?

Will be all take-home. Check the course directory for lastyear's �nal exam key.Will be available on the web in our course directory on Friday,April 27, 1:00 pm.Will be due on Thursday, April 3, 1:00 pm.

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 6: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

An Intelligent Opponent: Game TheoryAn Indi�erent Opponent: NatureDecision Making with Experimentation

Sidebar: Grades and Final

What's the Score?

The grade lines are

A: 87%, B: 76%, C: 60%I will use this for both homework and midterm.Final Exam scale will be similar.

And what about the �nal?

Will be all take-home. Check the course directory for lastyear's �nal exam key.Will be available on the web in our course directory on Friday,April 27, 1:00 pm.Will be due on Thursday, April 3, 1:00 pm.

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 7: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

An Intelligent Opponent: Game TheoryAn Indi�erent Opponent: NatureDecision Making with Experimentation

Sidebar: Grades and Final

What's the Score?

The grade lines are

A: 87%, B: 76%, C: 60%I will use this for both homework and midterm.Final Exam scale will be similar.

And what about the �nal?

Will be all take-home. Check the course directory for lastyear's �nal exam key.Will be available on the web in our course directory on Friday,April 27, 1:00 pm.Will be due on Thursday, April 3, 1:00 pm.

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 8: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Review Model Problem Data

The Payo� Table and Conditional Probability Data:

Payo�sAlternatives

States of Nature

Acceptable Unacceptable

Develop IPSell IP

Prior Probabilities

$7M −$1M$0.85M $0.85M

0.25 0.75

Conditional ProbsRecommendations

States of Nature

Acceptable Unacceptable

DevelopSell

0.6 0.20.4 0.8

Cost of Consulting: $30,000 = $0.03M.

Page 9: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Review Model Problem Data

The Payo� Table and Conditional Probability Data:

Payo�sAlternatives

States of Nature

Acceptable Unacceptable

Develop IPSell IP

Prior Probabilities

$7M −$1M$0.85M $0.85M

0.25 0.75

Conditional ProbsRecommendations

States of Nature

Acceptable Unacceptable

DevelopSell

0.6 0.20.4 0.8

Cost of Consulting: $30,000 = $0.03M.

Page 10: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Review Model Problem Data

The Payo� Table and Conditional Probability Data:

Payo�sAlternatives

States of Nature

Acceptable Unacceptable

Develop IPSell IP

Prior Probabilities

$7M −$1M$0.85M $0.85M

0.25 0.75

Conditional ProbsRecommendations

States of Nature

Acceptable Unacceptable

DevelopSell

0.6 0.20.4 0.8

Cost of Consulting: $30,000 = $0.03M.

Page 11: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Review Model Problem Data

The Payo� Table and Conditional Probability Data:

Payo�sAlternatives

States of Nature

Acceptable Unacceptable

Develop IPSell IP

Prior Probabilities

$7M −$1M$0.85M $0.85M

0.25 0.75

Conditional ProbsRecommendations

States of Nature

Acceptable Unacceptable

DevelopSell

0.6 0.20.4 0.8

Cost of Consulting: $30,000 = $0.03M.

Page 12: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Review Model Problem Data

The Payo� Table and Conditional Probability Data:

Payo�sAlternatives

States of Nature

Acceptable Unacceptable

Develop IPSell IP

Prior Probabilities

$7M −$1M$0.85M $0.85M

0.25 0.75

Conditional ProbsRecommendations

States of Nature

Acceptable Unacceptable

DevelopSell

0.6 0.20.4 0.8

Cost of Consulting: $30,000 = $0.03M.

Page 13: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

An Intelligent Opponent: Game TheoryAn Indi�erent Opponent: NatureDecision Making with Experimentation

Outline

1 NT: Decision Analysis and Game TheoryAn Intelligent Opponent: Game TheoryAn Indi�erent Opponent: NatureDecision Making with Experimentation

2 Odds and Ends

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 14: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Probability Background

Table of Conditional Probabilities and what to use on them:

ConsultantRecommendations

States of Nature

Acceptable Unacceptable

DevelopSell

P (D |A) P (D |U)P (S |A) P (S |U)

Bayes' Decision Rule: Calculate the expected value of thepayo� for each alternative using the best available estimates ofthe probabilities of the states of nature.

Law of Total Probability: Given disjoint and exhaustiveevents E1,E2,, . . . ,En, and another event F ,P (F ) =

∑ni=1

P (F |Ei )P (Ej).

(Short) Bayes' Theorem: P (E | F ) ≡ P(F |E)P(E)P(F ) .

(Long) Bayes' Theorem: P (Ek | F ) ≡ P(F |Ek)P(Ek)Pni=1 P(F |Ei )P(Ej)

.

Page 15: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Probability Background

Table of Conditional Probabilities and what to use on them:

ConsultantRecommendations

States of Nature

Acceptable Unacceptable

DevelopSell

P (D |A) P (D |U)P (S |A) P (S |U)

Bayes' Decision Rule: Calculate the expected value of thepayo� for each alternative using the best available estimates ofthe probabilities of the states of nature.

Law of Total Probability: Given disjoint and exhaustiveevents E1,E2,, . . . ,En, and another event F ,P (F ) =

∑ni=1

P (F |Ei )P (Ej).

(Short) Bayes' Theorem: P (E | F ) ≡ P(F |E)P(E)P(F ) .

(Long) Bayes' Theorem: P (Ek | F ) ≡ P(F |Ek)P(Ek)Pni=1 P(F |Ei )P(Ej)

.

Page 16: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Probability Background

Table of Conditional Probabilities and what to use on them:

ConsultantRecommendations

States of Nature

Acceptable Unacceptable

DevelopSell

P (D |A) P (D |U)P (S |A) P (S |U)

Bayes' Decision Rule: Calculate the expected value of thepayo� for each alternative using the best available estimates ofthe probabilities of the states of nature.

Law of Total Probability: Given disjoint and exhaustiveevents E1,E2,, . . . ,En, and another event F ,P (F ) =

∑ni=1

P (F |Ei )P (Ej).

(Short) Bayes' Theorem: P (E | F ) ≡ P(F |E)P(E)P(F ) .

(Long) Bayes' Theorem: P (Ek | F ) ≡ P(F |Ek)P(Ek)Pni=1 P(F |Ei )P(Ej)

.

Page 17: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Probability Background

Table of Conditional Probabilities and what to use on them:

ConsultantRecommendations

States of Nature

Acceptable Unacceptable

DevelopSell

P (D |A) P (D |U)P (S |A) P (S |U)

Bayes' Decision Rule: Calculate the expected value of thepayo� for each alternative using the best available estimates ofthe probabilities of the states of nature.

Law of Total Probability: Given disjoint and exhaustiveevents E1,E2,, . . . ,En, and another event F ,P (F ) =

∑ni=1

P (F |Ei )P (Ej).

(Short) Bayes' Theorem: P (E | F ) ≡ P(F |E)P(E)P(F ) .

(Long) Bayes' Theorem: P (Ek | F ) ≡ P(F |Ek)P(Ek)Pni=1 P(F |Ei )P(Ej)

.

Page 18: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Probability Background

Table of Conditional Probabilities and what to use on them:

ConsultantRecommendations

States of Nature

Acceptable Unacceptable

DevelopSell

P (D |A) P (D |U)P (S |A) P (S |U)

Bayes' Decision Rule: Calculate the expected value of thepayo� for each alternative using the best available estimates ofthe probabilities of the states of nature.

Law of Total Probability: Given disjoint and exhaustiveevents E1,E2,, . . . ,En, and another event F ,P (F ) =

∑ni=1

P (F |Ei )P (Ej).

(Short) Bayes' Theorem: P (E | F ) ≡ P(F |E)P(E)P(F ) .

(Long) Bayes' Theorem: P (Ek | F ) ≡ P(F |Ek)P(Ek)Pni=1 P(F |Ei )P(Ej)

.

Page 19: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Probability Background

Table of Conditional Probabilities and what to use on them:

ConsultantRecommendations

States of Nature

Acceptable Unacceptable

DevelopSell

P (D |A) P (D |U)P (S |A) P (S |U)

Bayes' Decision Rule: Calculate the expected value of thepayo� for each alternative using the best available estimates ofthe probabilities of the states of nature.

Law of Total Probability: Given disjoint and exhaustiveevents E1,E2,, . . . ,En, and another event F ,P (F ) =

∑ni=1

P (F |Ei )P (Ej).

(Short) Bayes' Theorem: P (E | F ) ≡ P(F |E)P(E)P(F ) .

(Long) Bayes' Theorem: P (Ek | F ) ≡ P(F |Ek)P(Ek)Pni=1 P(F |Ei )P(Ej)

.

Page 20: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Probability Connections

The table (or matrix Q for posterior probabilities) that we want:

State of Nature

Consultant Recommends

Develop Sell

AcceptableUnacceptable

P (A |D) P (A | S)P (U |D) P (U | S)

In matrix form Q can be calculated from Bayes' theorem as[P (A |D) P (A | S)P (U |D) P (U | S)

]=

[P(D |A)P(A)

P(D)P(S |A)P(A)

P(S)P(D |U)P(U)

P(D)P(S |U)P(U)

P(S)

]=[P (A) 00 P (U)

] [P (D |A) P (D |U)P (S |A) P (S |U)

]T [1

P(D) 0

0 1

P(S)

]and by the law of total probability unconditional probabilities

are

[P (D)P (S)

]=

[P (D |A) P (D |U)P (S |A) P (S |U)

] [P (A)P (U)

].

Page 21: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Probability Connections

The table (or matrix Q for posterior probabilities) that we want:

State of Nature

Consultant Recommends

Develop Sell

AcceptableUnacceptable

P (A |D) P (A | S)P (U |D) P (U | S)

In matrix form Q can be calculated from Bayes' theorem as[P (A |D) P (A | S)P (U |D) P (U | S)

]=

[P(D |A)P(A)

P(D)P(S |A)P(A)

P(S)P(D |U)P(U)

P(D)P(S |U)P(U)

P(S)

]=[P (A) 00 P (U)

] [P (D |A) P (D |U)P (S |A) P (S |U)

]T [1

P(D) 0

0 1

P(S)

]and by the law of total probability unconditional probabilities

are

[P (D)P (S)

]=

[P (D |A) P (D |U)P (S |A) P (S |U)

] [P (A)P (U)

].

Page 22: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Probability Connections

The table (or matrix Q for posterior probabilities) that we want:

State of Nature

Consultant Recommends

Develop Sell

AcceptableUnacceptable

P (A |D) P (A | S)P (U |D) P (U | S)

In matrix form Q can be calculated from Bayes' theorem as[P (A |D) P (A | S)P (U |D) P (U | S)

]=

[P(D |A)P(A)

P(D)P(S |A)P(A)

P(S)P(D |U)P(U)

P(D)P(S |U)P(U)

P(S)

]

=[P (A) 00 P (U)

] [P (D |A) P (D |U)P (S |A) P (S |U)

]T [1

P(D) 0

0 1

P(S)

]and by the law of total probability unconditional probabilities

are

[P (D)P (S)

]=

[P (D |A) P (D |U)P (S |A) P (S |U)

] [P (A)P (U)

].

Page 23: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Probability Connections

The table (or matrix Q for posterior probabilities) that we want:

State of Nature

Consultant Recommends

Develop Sell

AcceptableUnacceptable

P (A |D) P (A | S)P (U |D) P (U | S)

In matrix form Q can be calculated from Bayes' theorem as[P (A |D) P (A | S)P (U |D) P (U | S)

]=

[P(D |A)P(A)

P(D)P(S |A)P(A)

P(S)P(D |U)P(U)

P(D)P(S |U)P(U)

P(S)

]=[P (A) 00 P (U)

] [P (D |A) P (D |U)P (S |A) P (S |U)

]T [1

P(D) 0

0 1

P(S)

]

and by the law of total probability unconditional probabilities

are

[P (D)P (S)

]=

[P (D |A) P (D |U)P (S |A) P (S |U)

] [P (A)P (U)

].

Page 24: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Probability Connections

The table (or matrix Q for posterior probabilities) that we want:

State of Nature

Consultant Recommends

Develop Sell

AcceptableUnacceptable

P (A |D) P (A | S)P (U |D) P (U | S)

In matrix form Q can be calculated from Bayes' theorem as[P (A |D) P (A | S)P (U |D) P (U | S)

]=

[P(D |A)P(A)

P(D)P(S |A)P(A)

P(S)P(D |U)P(U)

P(D)P(S |U)P(U)

P(S)

]=[P (A) 00 P (U)

] [P (D |A) P (D |U)P (S |A) P (S |U)

]T [1

P(D) 0

0 1

P(S)

]and by the law of total probability unconditional probabilities

are

[P (D)P (S)

]=

[P (D |A) P (D |U)P (S |A) P (S |U)

] [P (A)P (U)

].

Page 25: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Decision Trees

A Method for Visually Displaying the Problem and OrganizingComputational Work:

Draw a tree from left to right with square nodes for decisionsand round nodes for events.

Place decision and outcome labels above each branch, alongwith costs and expected payo�s below each branch and labelsand (best, prior or posterior) probabilities above each branch.

Fill in the tree by working from right to left.

For each decision node, compare expected payo�s of eachbranch and choose the decision with largest expected payo�, inaccordance with Bayes' Decision Rule.

Let's set this up at the board.

How can we use Matlab to help us out?

Let's de�ne a conditionals matrix and calculate theprobabilities of each recommendation and then.

Page 26: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Decision Trees

A Method for Visually Displaying the Problem and OrganizingComputational Work:

Draw a tree from left to right with square nodes for decisionsand round nodes for events.

Place decision and outcome labels above each branch, alongwith costs and expected payo�s below each branch and labelsand (best, prior or posterior) probabilities above each branch.

Fill in the tree by working from right to left.

For each decision node, compare expected payo�s of eachbranch and choose the decision with largest expected payo�, inaccordance with Bayes' Decision Rule.

Let's set this up at the board.

How can we use Matlab to help us out?

Let's de�ne a conditionals matrix and calculate theprobabilities of each recommendation and then.

Page 27: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Decision Trees

A Method for Visually Displaying the Problem and OrganizingComputational Work:

Draw a tree from left to right with square nodes for decisionsand round nodes for events.

Place decision and outcome labels above each branch, alongwith costs and expected payo�s below each branch and labelsand (best, prior or posterior) probabilities above each branch.

Fill in the tree by working from right to left.

For each decision node, compare expected payo�s of eachbranch and choose the decision with largest expected payo�, inaccordance with Bayes' Decision Rule.

Let's set this up at the board.

How can we use Matlab to help us out?

Let's de�ne a conditionals matrix and calculate theprobabilities of each recommendation and then.

Page 28: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Decision Trees

A Method for Visually Displaying the Problem and OrganizingComputational Work:

Draw a tree from left to right with square nodes for decisionsand round nodes for events.

Place decision and outcome labels above each branch, alongwith costs and expected payo�s below each branch and labelsand (best, prior or posterior) probabilities above each branch.

Fill in the tree by working from right to left.

For each decision node, compare expected payo�s of eachbranch and choose the decision with largest expected payo�, inaccordance with Bayes' Decision Rule.

Let's set this up at the board.

How can we use Matlab to help us out?

Let's de�ne a conditionals matrix and calculate theprobabilities of each recommendation and then.

Page 29: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Decision Trees

A Method for Visually Displaying the Problem and OrganizingComputational Work:

Draw a tree from left to right with square nodes for decisionsand round nodes for events.

Place decision and outcome labels above each branch, alongwith costs and expected payo�s below each branch and labelsand (best, prior or posterior) probabilities above each branch.

Fill in the tree by working from right to left.

For each decision node, compare expected payo�s of eachbranch and choose the decision with largest expected payo�, inaccordance with Bayes' Decision Rule.

Let's set this up at the board.

How can we use Matlab to help us out?

Let's de�ne a conditionals matrix and calculate theprobabilities of each recommendation and then.

Page 30: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Decision Trees

A Method for Visually Displaying the Problem and OrganizingComputational Work:

Draw a tree from left to right with square nodes for decisionsand round nodes for events.

Place decision and outcome labels above each branch, alongwith costs and expected payo�s below each branch and labelsand (best, prior or posterior) probabilities above each branch.

Fill in the tree by working from right to left.

For each decision node, compare expected payo�s of eachbranch and choose the decision with largest expected payo�, inaccordance with Bayes' Decision Rule.

Let's set this up at the board.

How can we use Matlab to help us out?

Let's de�ne a conditionals matrix and calculate theprobabilities of each recommendation and then.

Page 31: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Decision Trees

A Method for Visually Displaying the Problem and OrganizingComputational Work:

Draw a tree from left to right with square nodes for decisionsand round nodes for events.

Place decision and outcome labels above each branch, alongwith costs and expected payo�s below each branch and labelsand (best, prior or posterior) probabilities above each branch.

Fill in the tree by working from right to left.

For each decision node, compare expected payo�s of eachbranch and choose the decision with largest expected payo�, inaccordance with Bayes' Decision Rule.

Let's set this up at the board.

How can we use Matlab to help us out?

Let's de�ne a conditionals matrix and calculate theprobabilities of each recommendation and then.

Page 32: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

Decision Trees

A Method for Visually Displaying the Problem and OrganizingComputational Work:

Draw a tree from left to right with square nodes for decisionsand round nodes for events.

Place decision and outcome labels above each branch, alongwith costs and expected payo�s below each branch and labelsand (best, prior or posterior) probabilities above each branch.

Fill in the tree by working from right to left.

For each decision node, compare expected payo�s of eachbranch and choose the decision with largest expected payo�, inaccordance with Bayes' Decision Rule.

Let's set this up at the board.

How can we use Matlab to help us out?

Let's de�ne a conditionals matrix and calculate theprobabilities of each recommendation and then.

Page 33: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

Game Theory Model Problem

The Problem:

Dominant strategy elimination and the more generalmaximin/minimax strategies will not solve the following problem.

Strategy

Player 2

1 2 3

Player 1123

2 3 -2-1 4 03 -2 -1

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 34: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

Game Theory Model Problem

The Problem:

Dominant strategy elimination and the more generalmaximin/minimax strategies will not solve the following problem.

Strategy

Player 2

1 2 3

Player 1123

2 3 -2-1 4 03 -2 -1

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 35: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

A Sensitivity Analysis

The Original Model Problem:

Two companies compete for the bulk of a shared market for acertain product and plan to execute one of three strategies. Bothmarketing departments analyzed them and have arrived atessentially the same �gures for outcomes.

The three strategies are:

Better packaging.An advertising campaign.Slight price reduction.

Suppose there is considerable uncertainty about the payo� inthe case that both players make a slight reduction in price.How could we clearly illustrate the e�ect of changes in thepayo� on the weight that one of the companies puts on thisstrategy?

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 36: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

A Sensitivity Analysis

The Original Model Problem:

Two companies compete for the bulk of a shared market for acertain product and plan to execute one of three strategies. Bothmarketing departments analyzed them and have arrived atessentially the same �gures for outcomes.

The three strategies are:

Better packaging.An advertising campaign.Slight price reduction.

Suppose there is considerable uncertainty about the payo� inthe case that both players make a slight reduction in price.How could we clearly illustrate the e�ect of changes in thepayo� on the weight that one of the companies puts on thisstrategy?

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 37: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

A Sensitivity Analysis

The Original Model Problem:

Two companies compete for the bulk of a shared market for acertain product and plan to execute one of three strategies. Bothmarketing departments analyzed them and have arrived atessentially the same �gures for outcomes.

The three strategies are:

Better packaging.An advertising campaign.Slight price reduction.

Suppose there is considerable uncertainty about the payo� inthe case that both players make a slight reduction in price.How could we clearly illustrate the e�ect of changes in thepayo� on the weight that one of the companies puts on thisstrategy?

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business

Page 38: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

One More Decision Analysis

Problem:

A credit manager must decide whether to extend a $100,000 credit

to a new small business customer.

Customers of this type generally �t into categories of poorrisk, average risk or good risk, with a corresponding pro�t of−15%, 10% and 20%, respectively.

Prior experience indicates that 20% of customers in thiscategory are poor risk, 50% are average and 30% are good.

Also, the manager could consult a credit-rating company for a$2,500 fee.

With this record, should we consider them?

Strategy

Actual (in percent)

Poor Average Good

EvaluationPoor

AverageGood

50 40 2040 50 4010 10 40

Page 39: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

One More Decision Analysis

Problem:

A credit manager must decide whether to extend a $100,000 credit

to a new small business customer.

Customers of this type generally �t into categories of poorrisk, average risk or good risk, with a corresponding pro�t of−15%, 10% and 20%, respectively.

Prior experience indicates that 20% of customers in thiscategory are poor risk, 50% are average and 30% are good.

Also, the manager could consult a credit-rating company for a$2,500 fee.

With this record, should we consider them?

Strategy

Actual (in percent)

Poor Average Good

EvaluationPoor

AverageGood

50 40 2040 50 4010 10 40

Page 40: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

One More Decision Analysis

Problem:

A credit manager must decide whether to extend a $100,000 credit

to a new small business customer.

Customers of this type generally �t into categories of poorrisk, average risk or good risk, with a corresponding pro�t of−15%, 10% and 20%, respectively.

Prior experience indicates that 20% of customers in thiscategory are poor risk, 50% are average and 30% are good.

Also, the manager could consult a credit-rating company for a$2,500 fee.

With this record, should we consider them?

Strategy

Actual (in percent)

Poor Average Good

EvaluationPoor

AverageGood

50 40 2040 50 4010 10 40

Page 41: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

One More Decision Analysis

Problem:

A credit manager must decide whether to extend a $100,000 credit

to a new small business customer.

Customers of this type generally �t into categories of poorrisk, average risk or good risk, with a corresponding pro�t of−15%, 10% and 20%, respectively.

Prior experience indicates that 20% of customers in thiscategory are poor risk, 50% are average and 30% are good.

Also, the manager could consult a credit-rating company for a$2,500 fee.

With this record, should we consider them?

Strategy

Actual (in percent)

Poor Average Good

EvaluationPoor

AverageGood

50 40 2040 50 4010 10 40

Page 42: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

One More Decision Analysis

Problem:

A credit manager must decide whether to extend a $100,000 credit

to a new small business customer.

Customers of this type generally �t into categories of poorrisk, average risk or good risk, with a corresponding pro�t of−15%, 10% and 20%, respectively.

Prior experience indicates that 20% of customers in thiscategory are poor risk, 50% are average and 30% are good.

Also, the manager could consult a credit-rating company for a$2,500 fee.

With this record, should we consider them?

Strategy

Actual (in percent)

Poor Average Good

EvaluationPoor

AverageGood

50 40 2040 50 4010 10 40

Page 43: JDEP 384H: Numerical Methods in Businesstshores1/Public/JDEP384hS07/Week16/J… · Final Exam scale will be similar. And what about the nal? Will be all take-home. Check the course

NT: Decision Analysis and Game TheoryOdds and Ends

Which Brings Us To...

THE END

Instructor: Thomas Shores Department of Mathematics JDEP 384H: Numerical Methods in Business