254 lines
8.4 KiB
Markdown
254 lines
8.4 KiB
Markdown
---
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id: the-failure-of-risk-management
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aliases: []
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tags:
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- type/media-commentary
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---
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# *The Failure of Risk Management*
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The Failure of Risk Management
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(Why It's Broken and How to Fix It)
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by Douglas W. Hubbard
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## Key Takeaways
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### Qualitative Metrics Must Be Avoided
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Qualitative risk analysis
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(i.e. risk matrices, scoring charts)
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departs from legitimate statistical methodology
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and has no robust evidence to suggest its efficacy.
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There is good reason to believe that such methods
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are deleterious to their intended purpose
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in contradiction to the common response
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that they are "better than nothing".
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### Utility as a Measure of Value
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Expected Value (Probability × Magnitude)
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alone can not predict or inform risky decisions,
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except for risk-neutral parties.
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People and organizations are risk-averse
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%% TODO: ... %%
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For risk-neutral parties, expected value = CME
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### Expert Opinion Must Be ~~Adjusted~~
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Expert opinion is valuable despite its flaws.
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%% TODO: ... %%
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The book details the statistically observable tendency for people
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to underestimate risk and to be overconfident in their beliefs.
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It describes the process of "calibration"
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by which people can be trained to compensate for this bias
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and make predictions far more accurately.
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Experts tend to be good at creating heuristics,
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but do not apply them consistently in practice.
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> [!example]
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> Chapter 7 describes a study where individual experts
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> were shown to estimate risk differently for identical cases.
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Chapter 13 introduces the [Brier Score](https://en.wikipedia.org/wiki/Brier_score)
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as a method of evaluating the performance of an estimator,
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evaluated as the mean squared error of their forecasts.
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#### The Difficulty of Calibration
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##### Boolean Examples
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> The melting point of tin is higher than the melting point of aluminum.
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> In English, the word “quality” is more frequently used that the word “speed”.
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reductive (used more frequently where?)
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> Any male pig is referred to as a hog.
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reductive (referred to by whom?)
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> California’s giant sequoia trees are named for an early 19th century leader of the Cherokee Indians.
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reductive
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> The Model T was the first car produced by Henry Ford.
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reductive (Henry Ford didn't produce cars)
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> When rolling 2 dice, a roll of 7 is more likely than a 3.
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facile
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> No one has ever been reported to have been hit by any object that fell from space.
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reductive (reported by whom?)
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> Sir Christopher Wren was a British anthropologist.
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> Pakistan does not border Russia.
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unnecessary negative form, otherwise good.
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> The Navy won the first Army-Navy football game.
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should specify the official event name, otherwise good.
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> The paperback version of the book “The Da Vinci Code”, as of July 2007, still ranks in the top 500 bestselling books on Amazon.
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obtuse phrasing, dated topic, otherwise good
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> Italian has more words than any other language.
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reductive (what is a word? what dialect?)
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> The month of August is named after a Greek god.
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borderline facile, reductive
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> The deepest ocean trench is deeper than the Grand Canyon.
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facile
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> Abraham Lincoln was the first president born in a log cabin.
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deceptive phrasing
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> As of July of 2007, more people search Google for “Harry Potter” than “Hillary Clinton” (according to GoogleTrends).
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obtuse phrasing, dated topic, otherwise good
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> The population of Alabama is higher than the population of Arizona.
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borderline facile, deceptive phrasing
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> No category 5 hurricane hit the US in 2004.
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> The UK is among the top 10 largest economies in the world (by GDP).
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> The movie Forest Gump has grossed more to date than E.T. The Extra Terrestrial.
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obtuse phrasing, dated topic, otherwise good
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##### Interval Examples
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> What percentage of bronze is typically made of copper?
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reductive
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> How many countries have at least one McDonald’s?
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As of when?
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> How many employees did eBay have in the first quarter of 2006
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> What was the population of Miami (within the city limits, not the entire metropolitan area) in 1990?
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> How many casualties did the French suffer in the Battle of Waterloo?
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> What is the range in miles of a Minuteman Missile?
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> What is the percentage of IT jobs in the US were unfilled in 1997?
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> The Supremes’ (with Diana Ross) song “Stop! In the Name of Love” was how long? (minutes, seconds)
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> How many undergraduates attended Cambridge in 1990?
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> If you could jump 50 feet straight up into the air, how many seconds would you be airborne before you landed?
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> How many gallons are in a bushel (they are both measures of volume)?
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> How many sovereign rulers has England had in the last thousand years?
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> If the air temperature was 5 degrees below zero (Fahrenheit) and the wind speed was 15 mph, what would the temperature adjusted for wind-chill be?
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> Average cost of testing in software development is what percentage of total project costs?
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> On average, if a software development project was projected to take 17 months, it actually takes how many months?
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> How many meters tall is the Sears Tower?
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> How many gold medals did Jesse Owens win at the 1936 Berlin Olympics?
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> In 2005, the average combined MPG for all US cars and light trucks on the road was how much?
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> The average house in the United States uses how many gallons of water per day?
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> What was the average price in the United States of a house sold in 2001?
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##### Writing Good Calibration Questions
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A good calibration question should not feel like it could be a "trick" question.
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Definitions/terminology are *always* contentious,
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questions based on them always feel deceptive.
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Interval "questions" should describe the quantity
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rather than phrase it as a question.
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##### Strategy for Answering Calibration Questions
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Confidence should never be less than probability of picking randomly
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(50% for true)
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### Luck Looks Like Skill
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> Chapter 7 p.154
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Hubbard describes a study which concluded that,
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given the number of German pilots and their overall victory/defeat figures,
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there was a ~30% chance an individual would achieve The Red Baron's record
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_by luck alone_.
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He later refers to the popular tendency
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to overvalue competence and undervalue luck
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in the role of achieving improbable accomplishments
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as the "Red Baron effect".
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### There's Always Enough Data
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Hubbard challenges the popular rebuttal
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that any industry is so niche that
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data sufficient for quantitative models
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does not exist.
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> [!quote] Fallacy of Close Analogy - p.236
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> ...the belief that unless two things are identical in every way,
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> nothing learned from one can be applied to the other.
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## Mentioned Topics and Abbreviations
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* Analytic Hierarchy Process (AHP)
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* Multi-Attribute Utility Theory (MAUT)
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* Actuarial Science
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* Options Theory (OT)
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* Modern Portfolio Theory (MPT)
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* Probabalistic Risk Analysis (PRA)
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* Value at Risk (VaR)
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* Loss-Exceedance Curve (LEC)
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* Risk Tolerance
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* Certain Monetary Equivalent (CME)
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* also called Certainty Equivalent
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## Critiques
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### _Exsupero Ursus_
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Hubbard uses _exsupero ursus_ to describe the tendency of his detractors
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to dismiss quantitative methods as inappropriate for their industry-specific risks.
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> [!quote] Chapter 9 p.195
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> Suppose a car buyer had a choice between buying two nearly identical automobiles,
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> Car A and Car B.
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> The only difference is that Car B is $1,000 more expensive,
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> has fifty thousand more miles, and was once driven into a lake.
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> But buyer chooses Car B because Car A doesn't fly.
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> Neither does Car B, of course,
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> but for some reason the buyer believes that Car A should fly
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> and therefore chooses Car B.
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> The buyer is committing the _exsupero ursus_ fallacy.
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Based on this strawman it is clear Hubbard believes his detractors are _correct_
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that qualitative methods can not capture the entire nuance of risk probability,
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but that they are failing to acknowledge that their preferred alternatives
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are not demonstrably more effective at doing so.
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The nuance Hubbard dismisses without addressing
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is the possibility of model _improvement_.
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A most competent detractor would be aware of the apparent contradiction
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but argue that their methods will eventually surpass quantitative methods
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if they are further developed.
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Such a position would additionally contextualize Hubbard's observations
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that detractors become emotional in their defense.
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To them, Hubbard's methods represent an attractive short-term gain
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that would exclude a long-term payoff.
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Hubbard's dismissal rubs me wrong
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because it reads exactly as he describes the
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"at least we're doing _something_" argument
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throughout the book and just pages earlier.
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