Methodology and scope
How the argument works
The animation uses familiar self-reinforcement to show the setup. The theorem asks a different question: when that process closes off other paths, does one realized market still contain enough comparison to recover contribution? This page shows the shortest route from the familiar mechanism to the paper’s distinct result.
- 01The market chooses
Contribution-related inputs and accumulated advantage shape who wins next.
- 02The contest can close
An early favorite may receive nearly all later opportunities.
- 03Evidence can run out
More activity may repeat the lead without meaningfully testing anyone else.
What the app shows
The general model gives each person or firm a score. That score combines a verified input with advantage already accumulated. The market turns the scores into the probabilities of receiving the next opportunity.
Contribution-related signal × accumulated advantage → chance of winning next.
Twenty-four creators with modeled audience-response multipliers from 0.84 to 1.18 compete for 1,600 recommendations. The feedback strength is fixed at 1.55, so both creator differences and accumulated exposure affect the next ranking.
For a firm, the accumulated advantage might be customers, contracts, an installed base or past sales. The exact measure must match the real market.
Fixed random seeds make every replay reproducible. The numbers illustrate the mechanism; they aren’t forecasts for a real platform or industry.
What counts as a real comparison
A recommendation, contract or sale is informative only when more than one competitor has a meaningful chance. If the favorite is almost certain to win, the market reveals almost nothing about everyone else.
is the chance left for a competitor other than the favorite. adds those chances over time.
As the chance left for everyone else approaches zero, the new information about contribution must also approach zero.
What the paper proves
Under the formal conditions below, finite total comparison means that one complete history can’t support a method that consistently learns every nonconstant measure of contribution.
The histories aren’t identical. They overlap too much for one realized history to identify every contribution measure consistently.
Formal conditions and boundaries
- The design is common and predictable from the same observed past.
- Nearby parameter values have locally equivalent one-step laws.
- Hellinger separation in both directions is controlled by the remaining comparison.
- Total comparison is finite under every parameter being compared.
- Any additional observed process with parameter-dependent information must be included.
- The conclusion is mutual absolute continuity of complete-history laws, not equality of distributions.
What can keep learning alive
The result isn’t a law of nature. Market and platform design can preserve new opportunities to compare people and firms.
Random exposure is an intervention: it changes the platform rule rather than merely measuring the original one.
What the result changes
Market rankings can’t by themselves settle moral or political questions about desert. They don’t reveal a clean earned-versus-unearned split.
Tax rates, public ownership, UBI and social dividends remain collective choices. They should be decided openly around power, security, freedom and shared prosperity, not outsourced to a market score.