Model Latticework
Use this file to choose the smallest useful set of models for the specific case. Usually 4 to 8 is enough.
Selection rule
Do not ask, "Which models do I know?" Ask, "Which models will materially change the answer?"
Mathematics and decision theory
Base rates
Use when the case belongs to a recognisable class.
Ask:
- What usually happens in situations like this?
- How often does this kind of plan fail, stall, or outperform?
Expected value
Use when there are discrete scenarios and payoffs.
Ask:
- What are the plausible scenarios?
- What is the probability-weighted payoff?
Opportunity cost
Use almost always.
Ask:
- Compared with what?
- What is the best alternative use of the same time, money, or reputation?
Compounding
Use when repeated small advantages or mistakes matter over time.
Ask:
- What accumulates here?
- Which path creates future optionality or future fragility?
Engineering and systems
Redundancy / backup systems
Use when failure is costly.
Ask:
- What happens if the key assumption breaks?
- Where is the backup?
Bottleneck
Use when outcomes depend on one scarce constraint.
Ask:
- What single constraint governs throughput or quality?
- What happens if that constraint worsens?
Breakpoint / critical mass
Use when effects are non-linear.
Ask:
- Is there a threshold after which the result changes sharply?
- Are we below the threshold, near it, or through it?
Feedback loops
Use when behaviour changes behaviour.
Ask:
- What self-reinforcing loop is being created?
- Is the loop stabilising or destabilising?
Economics and business
Incentives
Use always when people are involved.
Ask:
- What is each actor rewarded for?
- What are they likely to optimise in practice rather than in theory?
Comparative advantage / specialization
Use when deciding who should do what.
Ask:
- Who has the real edge?
- Is this task sitting with the highest-value actor?
Moats / durable advantage
Use for competitive questions.
Ask:
- Why is this defensible?
- What would stop a rival copying, undercutting, or displacing it?
Scale advantages and disadvantages
Use when growth is central.
Ask:
- Does scale improve economics, data, distribution, or trust?
- Or does scale mainly create bureaucracy and slop?
Psychology
Social proof
Use when crowd behaviour is salient.
Ask:
- Are people believing this because it is true or because others believe it?
Inconsistency avoidance / sunk cost
Use when commitment is already high.
Ask:
- Is the user defending the past instead of choosing afresh?
Deprival-superreaction
Use when near-loss, actual loss, or fear of shrinking matters.
Ask:
- Is the desire to avoid loss stronger than the rational case for the next step?
Overoptimism
Use in plans, forecasts, and entrepreneurship.
Ask:
- Which costs, timeframes, or difficulties are being understated?
Stress influence
Use when timing is ugly or pressure is high.
Ask:
- How is stress distorting judgement, courage, or honesty?
Biology and adaptation
Evolution / selection
Use when systems reward what survives, not what sounds good.
Ask:
- Which behaviours get selected over time by this environment?
- Does the system breed honesty or gaming?
Adaptation
Use when the environment is changing.
Ask:
- What happens if the environment moves faster than the plan?
History
Vicarious learning
Use always when there are precedents.
Ask:
- Who has already made this mistake?
- Which prior case is structurally similar, not merely superficially similar?
Practical guidance
- If the user is choosing between options, opportunity cost and incentives are usually mandatory.
- If the user is forecasting, use base rates, overoptimism, and feedback loops.
- If the case is political, social, or organisational, social proof, authority, and incentives dominate more often than technical elegance.
- If the case is emotionally loaded, add stress influence, deprival-superreaction, and identity-linked distortions.