Files
zmVault/klugman-et-al_2019_loss-models.md
T

10 KiB

title, tags, author, edition, publisher, series, subtitle, type, year
title tags author edition publisher series subtitle type year
Loss Models: From Data to Decisions, Fifth Edition
authorship/other
exclude-from-word-count
topic/risk
type/media/book
Gordon E. Willmot & Harry H. Panjer & 3 Fifth John Wiley & Sons Wiley Series in Probability and Statistics From Data to Decisions book 2019

Loss Models: From Data to Decisions, Fifth Edition

%% This note, with the exception of comments like this one (reserved for notes on transcription) consists only of content from the text. For commentary see the companion loss-models. %%

Part I Introduction

1. Modeling

1.1 The Model-Based Approach

1.1.1 The Modeling Process

The model-based approach should be considered in the context of the objectives of any given problem. Many problems in actuarial science involve the building of a mathematical model that can be used to forecast or predict insurance costs in the future.

1.1.2 The Modeling Advantage

1.2 The Organization of This Book

2. Random Variables

2.1 Introduction

2.2 Key Functions and Four Models

2.2.1 Exercises

3. Basic Distributional Quantities

3.1 Moments

3.1.1 Exercises

3.2 Percentiles

3.2.1 Exercises

3.3 Generating Functions and Sums of Random Variables

3.3.1 Exercises

3.4 Tails of Distributions

3.4.1 Classification Based on Moments
3.4.2 Comparison Based on Limiting Tail
3.4.3 Classification Based on the Hazard Rate Function
3.4.4 Classification Based on the Mean Excess Loss Function The mean excess
3.4.5 Equilibrium Distributions and Tail Behavior
3.4.6 Exercises

3.5 Measures of Risk

3.5.1 Introduction
3.5.2 Risk Measures and Coherence
3.5.3 Value at Risk
3.5.4 Tail Value of Risk
3.5.5 Exercises

Part II Actuarial Models

4. Characteristics Of Actuarial Models

4.1 Introduction

4.2 The Role of Parameters

4.2.1 Parametric and Scale Distributions
4.2.2 Parametric Distribution Families
4.2.3 Finite Mixture Distributions
4.2.4 Data-Dependent Distributions
4.2.5 Exercises

5. Continuous Models

5.1 Introduction

5.2 Creating New Distributions

5.2.1 Multiplication by a Constant
5.2.2 Raising to a Power
5.2.3 Exponentiation
5.2.4 Mixing
5.2.5 Frailty Models
5.2.6 Splicing
5.2.7 Exercises

5.3 Selected Distributions and Their Relationships

5.3.1 Introduction
5.3.2 Two Parametric Families
5.3.3 Limiting Distributions
5.3.4 Two Heavy-Tailed Distributions
5.3.5 Exercises

5.4 The Linear Exponential Family

5.4.1 Exercises

6. Discrete Distributions

6.1 Introduction

6.1.1 Exercise

6.2 The Poisson Distribution

6.3 The Negative Binomial Distribution

6.4 The Binomial Distribution

6.5 The (a,b) Class

6.5.1 Exercises

6.6 Truncation and Modification at zero

6.6.1 Exercises

7. Advanced Discrete Distributions

7.1 Compound Frequency Distributions

7.1.1 Exercises

7.2 Further Properties of the Compound Poisson Class

7.2.1 Exercises

7.3 Mixed-Frequency Distributions

7.3.1 The General Mixed-Frequency Distribution
7.3.2 Mixed Poisson Distributions
7.3.3 Exercises

7.4 The Effect of Exposure on Frequency

7.5 An Inventory of Discrete Distributions

7.5.1 Exercises

8. Frequency And Severity With Coverage Modifications

8.1 Introduction

8.2 Deductibles

8.2.1 Exercises

8.3 The Loss Elimination Ratio and the Effect of Inflation for Ordinary Deductibles

8.3.1 Exercise

8.4 Policy Limits

8.4.1 Exercises

8.5 Coinsurance, Deductibles, and Limits

8.5.1 Exercises

8.6 The Impact of Deductibles on Claim Frequency

8.6.1 Exercises

9. Aggregate Loss Models

9.1 Introduction

9.1.1 Exercises

9.2 Model Choices

9.2.1 Exercises

9.3 The Compound Model for Aggregate Claims

9.3.1 Probabilities and Moments
9.3.2 Stop-Loss Insurance
9.3.3 The Tweedle Distribution
9.3.4 Exercises

9.4 Analytic Results

9.4.1 Exercises

9.5 Computing the Aggregate Claims Distribution

9.6 The Recursive Method

9.6.1 Applications to Compound Frequency Models
9.6.2 Underflow/Overflow Problems
9.6.3 Numerical Stability
9.6.4 Continuous Severity
9.6.5 Constructing Arithmetic Distributions
9.6.6 Exercises

9.7 The Impact of Individual Policy Modifications on Aggregate Payments

9.7.1 Exercises

9.8 The individual Risk Model

9.8.1 The Model
9.8.2 Parametric Approximation
9.8.3 Compound Poisson Approximation
9.8.4 Exercises

Part III Mathematical Statistics

10. Introduction To Mathematical Statistics

10.1 Introduction and Four Data Sets

10.2 Point Estimation

10.2.1 Introduction
10.2.2 Measures of Quality
10.2.3 Exercises

10.3 Interval Estimation

10.3.1 Exercises

10.4 The Construction of Parametric Estimators

10.4.1 The Method of Moments and Percentile Matching
10.4.2 Exercises

10.5 Tests of Hypotheses

10.5.1 Exercise

11. Maximum Likelihood Estimation

11.1 Introduction

11.2 Individual Data

11.2.1 Exercises

11.3 Grouped Data

11.3.1 Exercises

11.4 Truncated or Censored Data

11.4.1 Exercises

11.5 Variance and Interval Estimation for Maximum Likelihood Estimators

11.5.1 Exercises

11.6 Functions of Asymptotically Normal Estimators

11.6.1 Exercises

11.7 Nonnormal Confidence Intervals

11.7.1 Exercise

12. Frequentist Estimation For Discrete Distributions

12.1 The Poisson Distribution

12.2 The Negative Binomial Distribution

12.3 The Binomial Distribution

12.4 The (a,b) Class

12.5 Compound Models

12.6 The Effect of Exposure on Maximum Likelihood Estimation

12.7 Exercises

13. Bayesian Estimation

13.1 Definitions and Bayes' Theorem

13.2 Inference and Prediction

13.2.1 Exercises

13.3 Conjugate Prior Distributions and the Linear Exponential Family

13.3.1 Exercises

13.4 Computational Issues

Part IV Construction Of Models

14. Construction Of Empirical Models

14.1 The Empirical Distribution

14.2 Empirical Distributions for Grouped Data

14.2.1 Exercises

14.3 Empirical Estimation with Right Censored Data

14.3.1 Exercises

14.4 Empirical Estimation of Moments

14.4.1 Exercises

14.5 Empirical Estimation with Left Truncated Data

14.5.1 Exercises

14.6 Kernel Density Models

14.6.1 Exercises

14.7 Approximations for large Data Sets

14.7.1 Introduction
14.7.2 Using Individual Data Points
14.7.3 Interval-Based Methods
14.7.4 Exercises

14.8 Maximum Likelihood Estimation of Decrement Probabilities

14.8.1 Exercise

14.9 Estimation of Transition Intensities

15. Model Selection

15.1 Introduction

15.2 Representations of the Data and Model

15.3 Graphical Comparison of the Density and Distribution Functions

15.3.1 Exercises

15.4 Hypothesis Tests

15.4.1 The Kolmogorov--Smirnov Test
15.4.2 The Anderson--Darling Test
15.4.3 The Chi-Square Goodness-of-Fit Test
15.4.4 The Likelihood Ratio Test
15.4.5 Exercises

15.5 Selecting a Model

15.5.1 Introduction
15.2.2 Judgement-Based Approaches
15.5.3 Score-Based Approaches
15.5.4 Exercises

Part V Credibility

16. Introduction To Limited Fluctuation Credibility

16.1 Introduction

16.2 Limited Fluctuation Credibility Theory

16.3 Full Credibility

16.4 Partial Credibility

16.5 Problems with the Approach

16.6 Notes and References

16.7 Exercises

17. Greatest Accuracy Credibility

17.1 Introduction

17.2 Conditional Distributions and Expectation

17.3 The Bayesian Methodology

17.4 The Credibility Premium

17.5 The Bühlmann Model

17.6 The Bühlmann--Straub Model

17.7 Exact Credibility

17.8 Notes and References

17.9 Exercises

18. Empirical Bayes Parameter Estimation

18.1 Introduction

18.2 Nonparametric Estimation

18.3 Semiparametric Estimation

18.4 Notes and References

18.5 Exercises

Part VI Simulation

19. Simulation

19.1 Basics of Simulation

19.1.1 The Simulation Approach
19.1.2 Exercises

19.2 Simulation for Specific Distributions

19.2.1 Discrete Mixtures
19.2.2 Time or Age of Death from a Life Table
19.2.3 Simulating from the (a,b) Class
19.2.4 Normal and Lognormal Distributions
19.2.5 Exercises

19.3 Determining the Sample Size

19.3.1 Exercises

19.4 Examples of Simulation in Actuarial Modeling

19.4.1 Aggregate Loss Calculations
19.4.2 Examples of Lack of Independence
19.4.3 Simulation Analysis of the Two Examples
19.4.4 The Use of Simulation to Determine Risk Measures
19.4.5 Statistical Analyses
19.4.6 Exercises

Appendix A An Inventory Of Continuous Distributions

A.1 Introduction

A.2 The Transformed Beta Family

A.2.1 The Four-Parameter Distribution

A.2.2 Three-Parameter Distributions

A.2.3 Two-Parameter Distributions

A.3 The Transformed Gamma Family

A.3.1 Three-Parameter Distributions

A.3.2 Two-Parameter Distributions

A.3.3 One-Parameter Distributions

A.4 Distributions For Large Losses

A.4.1 Extreme Value Distributions

A.4.2 Generalized Pareto Distributions

A.4.5 Other Distributions

A.4.6 Distributions With Finite Support

Appendix B An Inventory Of Discrete Distributions

B.1 Introduction

B.2 The (a,b,0) Class

B.3 The (a,b,1) Class

B.3.1 The Zero-Truncated Subclass

B.3.2 The Zero-Modified Subclass

B.4 The Compound Class

B.4.1 Some Compound Distributions

B.5 A Hierarchy Of Discrete Distributions

Appendix C Frequency And Severity Relationships

Appendix D The Recursive Formula

Appendix E Discretization Of The Severity Distribution

E.1 The Method Of Rounding

E.2 Mean Preserving

E.3 Undiscretization Of A Discretized Distribution

References

Index