Economics & Markets
Section 1
Core Idea
Evolutionary game theory studies how strategies spread in a population when payoffs determine reproductive or imitation success. There are no rational, calculating players — only strategies that do well or poorly and thus grow or shrink in share. The central solution concept is the evolutionarily stable strategy (ESS): a strategy that, once predominant, cannot be invaded by a small fraction of mutants. It explains cooperation, aggression, and conventions (e.g. driving on one side) as emergent from payoff structure and dynamics. For founders, the lens is "what behaviour would be stable if everyone copied successful players?" — that's often what you get in the long run, even without perfect rationality.
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Section 2
How to See It
Culture
You're seeing Evolutionary Game Theory when norms and behaviours in a market or company persist because they're self-reinforcing — those who follow them do better, so they spread. Conventions (e.g. standard terms, formats) are often ESSs.
Markets
You're seeing it when industry practices (pricing, quality, disclosure) settle into patterns that no single player can profitably break. The pattern is "stable" in the evolutionary sense.
Strategy
You're seeing it when you ask "if everyone copied the best performer, what would the industry look like?" That's the evolutionary equilibrium — and the baseline to beat or differentiate from.
Section 3
How to Use It
Identify the payoff structure: who does well when others do what? The strategy that does best when prevalent is a candidate ESS. To change the game, shift payoffs (e.g. make cooperation more rewarding) or change who interacts with whom (structure). Don't assume rationality; assume imitation of success.
Decision filter
"What behaviour, if everyone did it, would be hard to invade? That's the evolutionary equilibrium — work with it or change the payoffs so a better one emerges."
As a founder
When norms or practices seem stuck, ask what payoffs sustain them. To shift behaviour, change incentives (so the new behaviour does better) or selection (who gets copied). Culture and market conventions often behave like evolutionary equilibria.
Section 5
Founders & Leaders
Daniel EkCEO & Co-founder, Spotify
Ek navigated industry norms (labels, exclusives, pricing) that were evolutionarily stable — everyone had adapted to them. Spotify shifted payoffs (streaming economics, data, reach) so that cooperation with the new model became the best response. Founders can use the same lens: find the current ESS, then change the game so a better one is stable.
Section 7
Connected Models
Reinforces
Evolutionarily Stable Strategy
ESS is the solution concept of evolutionary game theory. A strategy is ESS if it does well against itself and better against invaders than they do against themselves. The model explains why certain behaviours persist without rational design.
Reinforces
Nash Equilibrium
In many evolutionary games, the ESS corresponds to a Nash equilibrium — but the logic is different (replication and invasion vs best response). Nash is "no one wants to deviate"; ESS is "mutants can't invade."
Leads-to
Tit-for-tat
Tit-for-tat and other reciprocal strategies were shown to be robust in evolutionary simulations (Axelrod). Cooperation can be an ESS when the game is repeated and payoffs favour reciprocity. The link is direct.
Section 8
One Key Quote
— John Maynard Smith, Evolution and the Theory of Games"A strategy is evolutionarily stable if, when the population uses it, no rare alternative strategy can invade. It is the game-theoretic analogue of a stable equilibrium in ecology."
Section 11
Summary & Further Reading
Evolutionary game theory: strategies spread by success; no rationality required. ESS: strategy that can't be invaded. Use it to explain conventions, norms, and industry equilibria. To change behaviour, change payoffs or structure so a better ESS emerges.
01
Book
Foundational text on ESS and evolutionary game theory.
02
Book
Tit-for-tat and cooperation in evolutionary simulations.
03