# Black Hole Index

> An open measurement instrument for structural lock-in in digital platforms. It produces a single dimensionless ratio, B = Capture / Escape, from eleven parameters scored on published five-anchor rubrics and combined by a published aggregation function. 184 platforms across 18 sectors are scored in the Q3 2026 release. Created by Ivan Savich, an independent researcher. All scores, rubrics and data are published under CC BY 4.0.

The index is a measurement, not a ranking of company quality and not a legal or regulatory conclusion. It measures how far a user, organisation or counterparty could leave a platform, not whether they should. Scores are the structured judgement of a single assessor applied under a published rubric; an inter-rater reliability study has been designed and pre-registered but has not yet been run, and until it reports every figure should be read as one assessor's judgement rather than an established measurement.

The project keeps an append-only public record of its own work, including every correction and withdrawal it has made. It begins on 22 August 2026 with the first frozen snapshot and its digest, and carries 38 dated entries, the most recent of them 7 September 2026. Nothing in it is edited after publication; corrections are appended with their dates, and several of the entries withdraw claims the project had published earlier.

## Core

- [Methodology](https://blackholeindex.com/methodology): the eleven parameters, their five-anchor rubrics, and the aggregation function in full
- [Rankings](https://blackholeindex.com/rankings): all 184 scored platforms across 18 sectors, with the decomposition of every score
- [Ownership maps](https://blackholeindex.com/rankings?view=group): 158 corporate maps covering all 184 scored systems — platforms belonging to one ecosystem group share a map, which is why there are fewer maps than platforms; each entity is read from a cited primary source and every figure is machine-checked against that source's own bytes
- [Research paper](https://blackholeindex.com/paper.md): the instrument's derivation, its theoretical grounding and its declared limitations. It reports a 100-platform, 12-sector cross-section and says so on its own first page; the live index has moved past it
- [Validation](https://blackholeindex.com/validation): what has and has not been established about the instrument, including what remains unproven
- [Robustness](https://blackholeindex.com/robustness): scoring-noise simulation and aggregation ablation

## Data

- [Scores, CSV](https://blackholeindex.com/bhi-scores.csv): the live release, all 184 rows with every parameter
- [Pinned Q3 2026 snapshot, CSV](https://blackholeindex.com/bhi-scores-q3-2026.csv): the frozen release cited by digest in regulatory submissions
- [Citation](https://blackholeindex.com/bhi-citation.bib): BibTeX

## Record

- [Public append-only record](https://blackholeindex.com/research-snapshots.txt): every dated entry, correction and withdrawal, with the digests of frozen material
- [Research note RN-001](https://blackholeindex.com/research/rn-001-portability-is-not-exit-capacity.md): why documented portability under-identifies exit capacity
- [Research note RN-002](https://blackholeindex.com/research/rn-002-cloud-core-identification-boundary.md): why a cloud measurement reported an identification boundary instead of a composite score

## Regulatory record

The authoritative copies are the authorities' own, and are linked here rather than summarised. A
response published in a consultation record was received and published; that is not endorsement,
and no regulator has adopted, evaluated or expressed a view on this instrument.

- [Response to the CMA consultation on a proposed steering conduct requirement for Apple's mobile platform](https://blackholeindex.com/cma-steering-response): submitted 20 July 2026 (the document itself carries a dateline of 21 July) and published by the UK Competition and Markets Authority under "Feedback received" as one of 37 non-confidential responses to that consultation, Apple's and Epic's among them, listed there as "Black Hole Index" — [consultation page on GOV.UK](https://www.gov.uk/government/consultations/proposed-steering-conduct-requirement-for-apples-mobile-platform), [the response as published (PDF, GOV.UK)](https://assets.publishing.service.gov.uk/media/6a7df0ac03b4fe14b1e7de20/Black_Hole_Index__1_.pdf). The CMA's update log for that page records "14 August 2026 — Responses published"; it gives no date against any individual response. The CMA's published copy has the author's contact e-mail removed and is otherwise identical to the copy here. Its figures are the Q3-2026 run and the live index has moved past them
- [Third-party submission to the CMA Call for Evidence on Apple and Google app store rules](https://blackholeindex.com/cma-submission): submitted 8 April 2026, unsolicited; receipt acknowledged by the Digital Markets Unit on 13 April 2026. Not published by the CMA. Its figures are the Q1-2026 run, and one of them is wrong: it gives Netflix B = 0.43 where the instrument returns 1.00. The page carries a dated erratum and the correction is in the public record

## Optional

- [Compare](https://blackholeindex.com/compare): two platforms side by side
- [Observatory](https://blackholeindex.com/observatory): interactive exploration of the scored universe
- [Parameters](https://blackholeindex.com/parameters): each parameter with its anchors
- [Changelog](https://blackholeindex.com/changelog): what changed between releases
- [API documentation](https://blackholeindex.com/api-docs): programmatic access to the scores