What is it about?

Ergodicity is a model about how outcomes unfold over time vs. across many parallel “worlds”. In a non‑ergodic system, what looks good on average across many people or simulations can still destroy a single person over time (for example: repeatedly taking a small chance of ruin).

Thinking in terms of ergodicity means you care about your time path — what happens to you step by step — instead of being fooled by population averages, backtests, or one‑off “expected values”. You avoid strategies where one bad outcome can wipe out all future options, even if the average result on paper looks great.

Examples

• Investing: A strategy that has a positive expected return but a small chance of total ruin (e.g. 1% chance of blowing up your account each year) is non‑ergodic. On paper, the average might look great, but over time one blow‑up ruins you.
• Health: Regularly pushing yourself to the edge (no sleep, extreme diets, overtraining) might “work” for a while, but if it raises the risk of a serious, irreversible health event, it’s non‑ergodic. The one bad event dominates the story.
• Business/Career: Constantly making all‑in bets on a single client, channel, or employer can look efficient in the short term, but if losing that one pillar wipes you out, it’s a non‑ergodic setup.

How do I use ergodicity?