PRACTICAL SKILLS / PRACTICAL GUIDE
Decision Making Under Uncertainty
Use probabilities, scenarios and reversible experiments when the future cannot be known.
The short answer: Good decisions under uncertainty do not require perfect prediction. They define possible outcomes, estimate ranges, limit downside and update when new evidence arrives.
Separate decision from outcome
A sound process can produce a bad result because chance remains. Judge both the reasoning available at the time and the eventual outcome.
Use ranges
Replace one forecast with a base case, upside case and downside case. State which assumptions move the result from one case to another.
Value reversibility
When evidence is weak, prefer small tests and choices that are easy to undo. Reserve irreversible commitments for decisions with stronger support.
Set an update trigger
Decide in advance what new information, date or threshold will make you revisit the choice. This prevents both constant second-guessing and stubbornness.
Keep a decision record
Write what you knew, the alternatives considered and why you chose one. Review it after the outcome so luck does not quietly rewrite your memory of the process.
Put it into practice
Try this: Write a base, upside and downside case for one decision. Name the assumption that moves each case and set a date for reviewing it.
Sources and further reading
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Educational purpose: This guide provides general education. It does not provide personalised financial, investment, legal or tax advice.