Bibliographic record
Abstract
The market structure of platform competition is critically important to managers and policy makers. Network effects in these markets predict concentrated industry structures, whereas competitive effects and differentiation suggest the opposite. Standard theory offers little guidance—full rationality models have multiple equilibria with wildly varying market concentration. We relax full rationality in favor of a boundedly rational cognitive hierarchy model. Even small departures from full rationality allow sharp predictions—there is a unique equilibrium in every case. When participants single-home and platforms are vertically differentiated, a single dominant platform emerges. Multihoming can give rise to a strong–weak market structure: one platform is accessed by all, and the other is used as a backup by some agents. Horizontal differentiation, in contrast, leads to fragmentation. Differentiation, rather than competitive effects, mainly determines market structure.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.004 | 0.013 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.003 | 0.011 |
| Scholarly communication | 0.009 | 0.020 |
| Open science | 0.002 | 0.003 |
| Research integrity | 0.004 | 0.003 |
| Insufficient payload (model declined to judge) | 0.011 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".