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Knowledge is the only good; ignorance the only evil. Socrates

All Posts by Date

About
3 min
about
About me and the blog

Reading in 2025
20 min
about
vsi
reading
What I am reading in 2025.
Dec 31, 2025

PIR Book Examples in Aggregate
2 min
programming
pir
Python code to recreate exhibits from Pricing Insurance Risk book.
Jan 15, 2025

Better Markdown Snippets
1 min
meta
blog
Pithier markdown tips—just the things I forget…
Jan 13, 2025

Drawing with MidJourney
1 min
meta
Learning to use MidJoureny effectively.
Jan 13, 2025

Stable Distributions
4 min
notes
Tail and body behavior of stable distributions.
Jan 13, 2025

Fibonacci Chest—woodwork project No. 3
1 min
about
woodwork
An open frame chest with an oak frame, top, drawer runners and pulls, built in 2004. Hard maple…
Jan 1, 2025

Bowl Database
2 min
about
woodwork
This page is searchable database of the 149 bowls I turned between 2010 and 2017. The bowls are…
Dec 31, 2024

Reading in 2024
31 min
about
vsi
reading
2024: the year of the Very Short Introduction!
Dec 31, 2024

English History
6 min
about
vsi
reading
llm
English history since the Romans—a short summary.
Dec 8, 2024

Why I like Python
3 min
Python
programming
I like love Python the language. The libraries are a bonus and the reason I use Python. Here are a…
Nov 27, 2024

Classifying and Identifying Trees
3 min
notes
trees
Introduction to multipart-post on tree classification and Introduction.
Oct 19, 2024

Galaxies VSI
12 min
about
vsi
reading
The age of the Universe is determined by studying the largest things using general relativity. The…
Aug 15, 2024

Extreme Tails of the Normal Distribution
5 min
notes
probability
Estimating extreme quantiles of the normal distribution.
Jun 22, 2024

Chemistry VSI
5 min
about
vsi
reading
Bonds: ionic, covalent, metallic; reactions: proton transfer, electron transfer, radical, Lewis…
Jun 21, 2024

Particle Physics VSI
27 min
about
vsi
reading
There are seventeen fundamental particles: six quarks, six leptons, and five bosons.
Jun 21, 2024

Plate Tectonics VSI
16 min
about
vsi
reading
Lithosphere takes tens of millions of years to warm up when subducted into the asthenosphere.
Jun 21, 2024

What I Ask GPT
26 min
notes
llm
How GPT helped me cluster the questions I’ve asked it over the last year.
Jun 2, 2024

Potted Measure Theory
12 min
notes
llm
mathematics
probability
A quick summary of measure theory on the real line.
May 22, 2024

Energy Intensity of Internet Traffic
8 min
notes
llm
How much energy is required to transfer 1GB of data over the internet from London to Paris?
May 21, 2024

Geography VSI
5 min
about
vsi
llm
reading
Space, place, and environment.
May 19, 2024

Science and Pseudo-science
13 min
notes
llm
This post is another comparison of LLMs. I asked for a summary of Popper’s philosophy…
May 19, 2024

The Forgetting Curve
3 min
notes
llm
The forgetting curve is a concept that describes how the ability to recall information decreases…
May 19, 2024

Trees
16 min
notes
llm
LLM guided tree classification.
May 19, 2024

Defining Bullshit
3 min
notes
llm
LLM definitions of Bullshit.
May 9, 2024

Joplin-Evernote Migration Policy
7 min
about
llm
LLM’s offer advice on maintaining historical notes.
May 8, 2024

Non-Measurable Sets
7 min
notes
set theory
mathematics
Detailed construction of a non-Lebesgue measurable set, per Halmos.
May 3, 2024

Doob’s Upcrossing Lemma
6 min
notes
llm
probability
Doob’s optional stopping theorem is a fundamental result in probability theory, particularly in…
May 2, 2024

Geometric Brownian Motion, Yet Again!
2 min
notes
probability
A heuristic explanation of geometric Brownian motion
May 2, 2024

Waiting Time for a Random Walk to Hit One
1 min
notes
Let \(X_n\) be a symmetric random walk moving up or down by one at each step with equal…
May 2, 2024

The Incurred Loss Process
1 min
notes
llm
probability
insurance
mathematics
modeling
research
risk
Towards a theory of incurred loss processes, starting with a review of stochastic processes.
Apr 27, 2024

Reinsurance Decision Making
22 min
presentations
insurance
risk
pricing
What’s wrong the the constant cost of capital assumption
Apr 23, 2024

Why Go Spectral?
1 min
notes
presentations
insurance
pricing
risk
probability
Why and how to use insurance spectral pricing methods.
Apr 16, 2024

Compensators
6 min
notes
llm
probability
mathematics
Given an exponential random variable \(T\) with the hazard function \(\alpha(t) = t\), the…
Apr 12, 2024

Human Evolution VSI
3 min
about
vsi
reading
llm
Out of Africa or multiregional?
Apr 12, 2024

Keynes VSI
2 min
about
vsi
reading
llm
Economists should strive to be as useful as dentists.
Apr 12, 2024

Stars and The Sun VSIs
39 min
about
vsi
reading
llm
We are all made of atoms created in stars!
Apr 12, 2024

Conditional Expectations Given The Sum of Independent Random Variables with Regularly Varying Densities
7 min
notes
Summary of results and examples from a recent paper of Denuit et al.
Apr 4, 2024

The First World War VSI
8 min
about
vsi
reading
llm
“At the end of 1917 the prospects for the Allies still looked grim.”
Apr 1, 2024

Climate and Climate Change VSIs
19 min
about
vsi
reading
“IPCC 2021 states that the evidence for climate change is unequivocal, and there is a very high…
Mar 30, 2024

Hosting Documentation on GitHub Pages
8 min
meta
llm
Another comparison of LLMs.
Mar 24, 2024

File Consolidator
1 min
meta
Rationalizing years of file archives
Mar 20, 2024

LLM Comparison: Managing Sublime Text Projects
6 min
notes
llm
Gemini, GPT, and Claude answer questions about Sublime Text
Mar 20, 2024

LLM Comparison: Why Buy Insurance?
28 min
notes
llm
insurance
Editing and tidying up transcribed text using LLMs.
Mar 20, 2024

Large Cardinals and Set Theory
37 min
notes
llm
set theory
mathematics
What can “large cardinals” have to do with Lebesgue measurable sets? I asked Chat GPT to find out…
Mar 20, 2024

MJ Images
1 min
meta
Retrieving and processing Midjourney images.
Mar 20, 2024

Markdown snippets
5 min
meta
llm
blog
Handy Quarto markdown tips and techniques that are easy to forget (=I forget them).
Mar 20, 2024

Using TikZ in a blog page
1 min
meta
blog
Using great2 to process tikz into svg files for blog posts.
Mar 20, 2024

Conditional Probability
68 min
notes
probability
mathematics
\[ \def\E{\mathsf E} \def\A{\mathscr A} \def\B{\mathscr B} % for general sigma…
Mar 19, 2024

Gas
21 min
notes
llm
The ideal gas model and when it fails.
Mar 19, 2024

Weather VSI
7 min
about
vsi
reading
Different types of cloud.
Mar 19, 2024

How a Pneumatic Tire Works
33 min
about
llm
A car tire supports the weight of the car by the difference in tension in the top and bottom tire…
Mar 18, 2024

Isotopes VSI
12 min
about
vsi
reading
llm
Same on the outside but different on the inside; detect one atom in \(10^{-15}\); cosmogenic creation
Mar 16, 2024

Accounting VSI
1 min
about
vsi
reading
The earliest human written records are all accounts; expenses use assets so are entered on the…
Mar 12, 2024

Earth System Science VSI
10 min
about
vsi
reading
llm
The Earth has experienced huge changes over very long time frames but feedback induced stability…
Mar 12, 2024

Geophysics VSI
1 min
about
vsi
reading
To do
Mar 12, 2024

Global Catastrophes VSI
1 min
about
vsi
reading
Meteorites will kill us…or maybe a volcano or our own stupidity. Landslides could flood the US…
Mar 12, 2024

Ice
11 min
about
llm
Table showing different types of ice.
Mar 12, 2024

Insurance in the Arts
3 min
about
llm
Cases where insurance could change the plot in famous literature.
Mar 12, 2024

Magna Carta VSI
6 min
about
vsi
reading
llm
Charters were common; John was a really bad king; original MC included enforcement by 25 barons.
Mar 12, 2024

Midjourney Prompts
3 min
about
llm
Mention specific art styles, techniques, artists, or art movements.
Mar 12, 2024

Newton VSI
10 min
about
vsi
reading
llm
Newton: scientist, alchemist, anti-Trinitarian, MP, Master of the Mint.
Mar 12, 2024

Planets VSI
11 min
about
vsi
reading
llm
The asteroid Apophis will have a close encounter with the Earth miss on 2029-04-13, which is a…
Mar 12, 2024

Risk VSI
3 min
about
vsi
reading
Normative - descriptive - prescriptive: What should we do? What do we do? How can we improve?
Mar 12, 2024

Statistics VSI
2 min
about
vsi
reading
The technology of extracting meaning from data and of handling uncertainty. Mechanistic vs…
Mar 12, 2024

The Earth VSI
2 min
about
vsi
reading
llm
The Earth was very different a long time ago; microbes under the seafloor; paleomagnetism and…
Mar 12, 2024

The Ice Age VSI
3 min
about
vsi
reading
Ice bergs or ice sheets debate; seabed and ice cores; Milankovitch’s three cycles; global impact…
Mar 12, 2024

The Laws of Thermodynamics VSI
8 min
about
vsi
reading
llm
Temperature: most probable distribution over available states; conservation of energy; entropy…
Mar 12, 2024

The Period Table VSI
9 min
about
vsi
reading
llm
Potassium-Argon reversal. Where should hydrogen appear? Why the actinides and lanthanides appear…
Mar 12, 2024

Evensong Order of Service
4 min
about
Church of England Evensong Order of Service
Mar 6, 2024

Hyphens
2 min
about
llm
Chat GPT’s instructions on the use of hyphens.
Mar 2, 2024

Words
6 min
about
vsi
logophilia
Technical words from VSIs
Feb 28, 2024

Knowledge in Diagrams
2 min
about
A collection of explanatory diagrams
Feb 27, 2024

Ages of the Earth
51 min
about
llm
vsi
Earth and human timelines.
Feb 26, 2024

VSI Series
1 min
about
vsi
reading
List of Very Short Introduction Books.
Feb 24, 2024

Numpy meshgrid
2 min
Python
programming
This always confuses me. Here’s the help on meshgrid:
Feb 23, 2024

Matplotlib: tips and tricks
1 min
programming
Python
llm
Here are several things I always forget when using matplotlib. This post written with help from…
Feb 21, 2024

Podcast and Video Appearances
1 min
about
presentations
I have appeared as a guest on several podcasts and videos. See also my YouTube videos.
Feb 18, 2024

Reading Since 1990
1 min
about
reading
A searchable table of all the books I have read since 1990.
Feb 18, 2024

Quarto YAML and Markdown: tips and tricks
12 min
meta
programming
blog
Python
What I learned today by RTFD.
Feb 14, 2024

Chat GPT and Google Gemini Answer Programming Questions
31 min
notes
programming
Python
llm
I believe that large language models (LLMs) are the most amazing thing that has happened in my…
Feb 13, 2024

Effective Python: Classes
10 min
programming
Python
effective python
llm
Object oriented programming in Python
Feb 13, 2024

My Shelf of Favorite Books
5 min
about
Contents and history of my shelf of favorite books since 2003.
Feb 13, 2024

Catastrophes Ranked by Energy
8 min
notes
insurance
llm
catastrophe
Add summary here…
Feb 7, 2024

Code Snippets
3 min
programming
Python
int('000000007fff4070', base=16)
Feb 7, 2024

Effective Python: R Style Regression
25 min
programming
Python
effective python
I use R, but I love Python. However, let’s face it, basic linear regression in R is very…
Feb 7, 2024

The Cost of Goods Sold
1 min
presentations
insurance
risk
pricing
John Major and Stephen Mildenhall, CARe Meeting, June 9, 2021
Feb 7, 2024

Presentations Since 1996
12 min
about
presentations
Conference, meeting, and online talks and presentation since 1997.
Jan 1, 2024

Publications
1 min
about
publications
Journal articles, books, popular press, and working papers.
Jan 1, 2024

Resume
3 min
about
Professional and academic experience.
Jan 1, 2024

Abstracts from Mario Ghossoub’s Papers on Risk
15 min
notes
risk
Ghossoub’s Website
Dec 23, 2023

Effective Python: Floats
5 min
programming
Python
effective python
I studied math(s) for 9 years as a undergraduate and graduate student. I never came across a…
Oct 6, 2022

Effective Python: Building a Test DataFrame
1 min
programming
Python
effective python
It is often helpful to have a test dataframe. This function makes one with several optional…
Jul 5, 2022

Effective Python: Introspection
1 min
programming
Python
effective python
Get the arguments of a function. Used in aggregate.distr.Aggregate.
Jul 5, 2022

Effective Python: Munging Fitbit Data with Pandas
8 min
programming
Python
effective python
Pain lies at the intersection of the computer and the real-world. Real-world data is messy…
Jun 28, 2022

Reinsurance Optimization Literature Review
14 min
notes
risk
reinsurance
Catastrophe reinsurance provides insurance companies protection against excessive losses caused by…
May 11, 2022

Effective Python: Projects
4 min
programming
Python
effective python
The best way to learn Python is to use it to solve a real-life problem you face. I’m often asked…
Apr 5, 2022

Bon Pint
2 min
actuarial review
The nerdier regulars at the Bon Pint pub enjoy a peculiar number game. They start with an integer \…
Mar 30, 2022

Academic Descriptions of Risk
3 min
notes
risk
Equal probability lotteries \([a, b]\) describe outcomes \(a\) and \(b\), which can be fixed or…
Mar 15, 2022

Reinsurance Capital or Credential
1 min
notes
risk
reinsurance
insurance
Reinsurance: Capital or Credential?
Mar 15, 2022

Effective Python: Importing Data into Pandas
2 min
programming
Python
effective python
Problems arise when computers interact with the real world. You step out of a controlled…
Mar 11, 2022

ZFC Axioms
2 min
notes
The Zermelo-Frankel axioms of set theory: extension, foundation, pairing, union, power, infinity…
Mar 11, 2022

Non Bayesian Risk
6 min
notes
bayesian
pricing
insurance
risk
underwriting
Distortion risk measures
Mar 7, 2022

David Wright Notes
18 min
notes
What is the insurance business? What do you manufacture? I asked that question to a lot of people…
Mar 2, 2022

When is Premium Riskier Than Loss Slides
5 min
presentations
insurance
pricing
PIRC presentation comparing volatility from premium and loss uncertainty.
Mar 2, 2022

CEOs Talk About Risk
7 min
notes
risk
insurance
In my judgment, the calendar year or published combined ratio is the primary measure of…
Mar 1, 2022

Effective Python: Converting Datatypes in Pandas
1 min
programming
Python
effective python
Series method astype it is already a number and you want to change the type. Will not coerce.
Mar 1, 2022

Towards the Quantitative Analysis of Quantitative Factors
15 min
notes
pricing
insurance
risk
underwriting
process risk; param risk; winner’s curse; PAT; ambiguity; morale hazard; info asymmetry
Feb 28, 2022

Effective Python: Dates
11 min
programming
Python
effective python
Problems arise when computers interact with the real world. You step out of a controlled…
Feb 20, 2022

Effective Python: requests, BeautifulSoup, and web scraping
2 min
programming
Python
effective python
The requests library does for web interaction what pathlib.Path path does for files.
Feb 20, 2022

Risk and Return
11 min
notes
insurance
risk
There are no universally true statements about risk.
Feb 20, 2022

Effective Python: Introspection with Pandas
2 min
programming
Python
effective python
This code defines a function that extracts all an objects properties into a pandas dataframe. It…
Feb 15, 2022

Effective Python: Strings and Unicode
20 min
programming
Python
effective python
Ever cut and paste text between applications and get unexpected results? Particularly when the…
Feb 15, 2022

Effective Python: zip, enumerate, and iter
3 min
programming
Python
effective python
This short post looks at three built-in Python functions: zip, enumerate, and iter.
Feb 15, 2022

Effective Python: Files
9 min
programming
Python
effective python
If you write a program of any length, you will likely have to manipulate files and filenames.…
Feb 10, 2022

Hash Magic Encryption and Digital Signatures
9 min
notes
Hash functions are miraculous, helpful tools we have no right to expect to exist. They seem far…
Feb 8, 2022

Creating TeX Format Files
3 min
meta
blog
Creating a TeX format file for faster processing.
Feb 4, 2022

Cartograms
5 min
notes
programming
Source:
Feb 2, 2022

Wordle the Best Start
8 min
notes
probability
bayesian
Wordle is a popular word game. You have six chances to guess a five-letter word. For each guess…
Feb 1, 2022

ConvexConsiderations Quarto Blog Setup
1 min
meta
programming
blog
Defines containing folder
Jan 31, 2022

Active and Inactive Research
3 min
about
research
programming
insurance
Open projects.
Jan 20, 2022

Effective Python Outline
1 min
programming
Python
effective python
A series of posts about effective Python programming for the intermediate user.
Jan 20, 2022

Effective Python: Regular Expressions
1 min
programming
Python
regular expressions
Regular expressions are a wonderful shorthand way to select and manipulate strings.
Jan 20, 2022

Effective Python: Setting up Python Environments
1 min
programming
Python
Notes I found helpful setting up my Python environments.
Jan 20, 2022

Markdown
1 min
meta
The text in this box becomes the description for the page.
Jan 20, 2022

Modes of Convergence
6 min
notes
probability
Random variables can converge in several different ways. Here is a brief introduction…
Jan 20, 2022

Pricing Insurance Risk Book
3 min
publications
pricing
insurance
risk
pir
Contents, errata, and other information about Pricing Insurance Risk, my book written with John…
Jan 20, 2022

Pricing Seasonal Peril Catastrophe Bonds: A Simplified Approach
1 min
publications
insurance
pricing
catastrophe
We show a catastrophe bond’s economically meaningful cash flows are the same as a fully continuous…
Jan 20, 2022

Similar risks have similar prices: A useful and exact quantification
1 min
publications
research
insurance
pricing
This paper introduces an straightforward algorithm to determine a range of prices consistent with…
Jan 20, 2022

Pricing Insurance Risk Course (PIRC)
2 min
insurance
pricing
insurance
risk
pir
This course explains modern approaches to pricing insurance risk, the process of setting a…
Dec 31, 2021

The Aggregate Package
1 min
programming
Python
probability
The aggregate Python package makes working with aggregate loss distributions easy.
Dec 31, 2021

When is Premium Riskier Than Loss
1 min
An analysis of US statutory insurance data since 1992 shows that premium is more uncertain and…
Nov 30, 2021

A Modern Approach to Pricing for Risk
1 min
presentations
Liberty Mutual, November 2021
Nov 15, 2021

Bodoff’s Percentile Layer of Capital-Method
22 min
research
pricing
Bodoff’s paper1 describes a new approach to capital allocation; the catalyst for this new approach…
Jan 31, 2021

Equilibrium Risk Pools
1 min
research
insurance
risk
pricing
presentations
This research investigates equilibrium risk pools in a market with risk-based solvency regulation…
Oct 21, 2020

Minimum Bias and Exponential Family Distributions
6 min
research
probability
minimum bias
glm
exponential family
This post introduces four short expository notes describing exponential family distributions that…
Oct 21, 2020

Bailey Simon Minimum Bias Reexamined
25 min
actuarial review
publications
programming
minimum bias
glm
exponential family
modeling
Part I of a four part series “Minimum Bias and Exponential Family Distributions”.
Oct 20, 2020

Exponential Family Distributions
31 min
research
probability
insurance
probability
minimum bias
glm
exponential family
Part II of a four part series “Minimum Bias and Exponential Family Distributions”.
Oct 20, 2020

Probability Models for Insurance Losses
48 min
research
probability
insurance
minimum bias
glm
exponential family
Part III of a four part series “Minimum Bias and Exponential Family Distributions”.
Oct 20, 2020

The Tweedie Power Variance Function Family
30 min
research
probability
insurance
minimum bias
glm
exponential family
Part IV of a four part series “Minimum Bias and Exponential Family Distributions”.
Oct 20, 2020

Charging for Diversifiable Risk and Proud to Do It
1 min
presentations
John Major and Stephen Mildenhall, CAS Webinar, September 24, 2020.
Sep 24, 2020

Teaching
2 min
notes
teaching
From 2016-2020 I was Assistant Professor in the School of Risk Management, Insurance, and…
Aug 31, 2020

How to Allocate Capital if You Really Must
1 min
presentations
John Major and Stephen Mildenhall, CAS Spring Meeting, May 13, 2020
May 13, 2020

Spectral Risk Measures and Applications in Insurance ERM
1 min
presentations
John Major and Stephen Mildenhall, ASTIN Special Interest Webinar, March 25, 2020
Mar 25, 2020

ERM Saves the Day for the CEA
72 min
research
pricing
Abstract. Since its emergence in the 1990s enterprise risk management (ERM) has struggled to…
Oct 28, 2019

ERM Saves the Day for the CEA v2
72 min
research
pricing
Abstract. The California Earthquake Authority (CEA) became operational December 1, 1996. It was…
Aug 7, 2019

AI and Insurance
1 min
presentations
New AI techniques help computers solve problems that people find easy but that computers have…
May 20, 2019

Life Insurance Backdating
16 min
research
Assuming continuous rating the insured is always worse off with backdating on a net basis. A net…
Apr 15, 2019

Programming Your Career
13 min
actuarial review
publications
programming
I love to program, and I am convinced programming has been beneficial to my career. Other…
Jan 7, 2019

Blockchain and Insurance
1 min
presentations
Blockchain solves trust problems. If you trust your counter-parties, or operate in a country with…
Nov 13, 2018

Business Risk and Analytics
33 min
notes
risk
There is a synergistic relationship between business, analytics, and technology (the BAT triangle)…
Sep 15, 2018

Frequency Distributions
3 min
notes
probability
A random variable \(N\) is \(G\)-mixed Poisson if \(N\mid G\) has a Poisson \(nG\) distribution…
Sep 15, 2018

Summary of Insurance Priority Laws and Statutes
101 min
notes
insurance
Upon the issuance of a proper court order placing a domestic insurer in receivership or placing a…
Jul 19, 2018

In Praise of VaR Part II
14 min
actuarial review
publications
modeling
risk
“Can he have everything louder than everything else?” Ian Gillan, Deep Purple, Made In Japan
Jan 16, 2018

The Insurance Stack in a Disrupted World
131 min
research
insurance
pricing
DRAFT / work in progress!
Nov 15, 2017

In Praise of VaR Part I
11 min
actuarial review
publications
modeling
risk
VaR can misbehave,
Hiding dragons in the tail.
Many views reveal.
Nov 13, 2017

FinTech and InsurTech
1 min
presentations
Billions of dollars are flowing into new FinTech and InsurTech start-ups. How do these companies…
Nov 10, 2017

Bowls
1 min
about
woodwork
I have turned 149 bowls from a variety of North American woods.
Sep 1, 2017

Woodworking
1 min
about
woodwork
Between 2004 and 2013, I was a sporadically active woodworker with a basement shop.
Aug 31, 2017

Learning Objectives
64 min
notes
teaching
Learning objectives have three components:
May 17, 2017

Election Day Lessons for the Data Scientist
26 min
actuarial review
publications
modeling
risk
Kim Hypothetical, FCAS, is a pricing actuary in the Large Accounts department at Hypothetical…
Jan 22, 2017

The Black-Scholes Option Pricing Formula
1 min
presentations
insurance
pricing
risk
I had been fascinated by Black-Scholes since a fellow student at the University of Chicago math…
Sep 24, 1997

Wang’s Proportional Hazard Transform
1 min
presentations
pricing
insurance
Early description and exploration of the exciting (then) new Wang transform to my colleagues at…
Aug 27, 1997

Modeling Loss Ratios for Aggregate Features
1 min
research
insurance
risk
Very early work on aggregate loss distributions! From the introduction:
May 22, 1997

Premium Margins and Managing the Catastrophe Risk
1 min
research
insurance
risk
I applied the method to different lines of business, based on A.M. Bests’ aggregates and averages…
Aug 22, 1995

A Note on Elkies’ Proof
1 min
notes
research
This is a short three-page note on Elkies’ proof that an elliptic curve has infinitely many…
Mar 1, 1992
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