Antitrust Radar
AR-T02 / institutional research topic

Digital platforms

Digital Platforms

How do defaults, distribution, data access, interoperability, and adjacent-platform positions shape entry across separately measured digital systems?
Trace usage and referral screens into exact product, operator, official-record, and research links while keeping every digital denominator separate.
Evidence architecture5/5 active lanes
  1. Publications2editions
  2. Agenda questions12questions
  3. Issue programs1programs
  4. Public datasets9datasets
  5. Analysis routes5routes
Bar length is relative within this topicCounts retain different units
Publications
2
2 permanent series
Agenda questions
12
1 issue program
Public datasets
9
449 declared rows
Source links
9
reviewed through Jul 20, 2026

Topic boundary. Search, browser, mobile operating system, social referral, and AI-assistant usage are separate screens. Their adjacency does not establish one ecosystem market, common control, or a combined concentration measure.

Evidence standard
Institutional research topicDigital Platforms2 publications / 2 active releases / 5 evidence lanes

Research contract

Question, mandate, boundary, and evidence need

Public question

How do defaults, distribution, data access, interoperability, and adjacent-platform positions shape entry across separately measured digital systems?

Institutional mandate

Trace usage and referral screens into exact product, operator, official-record, and research links while keeping every digital denominator separate.

Interpretation boundary

Search, browser, mobile operating system, social referral, and AI-assistant usage are separate screens. Their adjacency does not establish one ecosystem market, common control, or a combined concentration measure.

Evidence still needed

Stable user and firm panels, default and distribution contracts, switching, multihoming, interoperability, data access, compute, price, quality, and entry records.

Primary audienceTechnology-policy researchers, reporters, authorities, and advocates

Publication chronology

How this subject entered the public record.

Every institutional release date remains on the axis, including dates with no publication assigned to this topic.
Active releases
2 / 6
Topic publications
2
Largest release
1
Release footprint by publication seriesHeight = new topic publications
  1. 0cumulative0 new
  2. 0cumulative0 new
  3. 0cumulative0 new
  4. 1cumulative1 new
  5. 1cumulative0 new
  6. 2cumulative1 new

Publication chronology, not impact. Counts describe when current corpus items entered the register. They are not output targets, quality measures, or evidence of policy effect.

Publication register

2 citable publications

Exact theme memberships across 2 permanent series.
State of CompetitionAR-SC0Methods and MeasuresAR-MM0Public Data NotesAR-DN0Research BriefsAR-RB1Competition InsightsAR-CI1International BriefsAR-ICP0
  1. AR-CI-2026-02Competition Insights

    Focused note / United States

    Four digital usage systems traced four different structural paths.

    Browser, mobile operating-system, search-engine, and social-referral shares are read side by side without turning them into one platform-power score.
    Published
    Aug 12, 2026
    Sources reviewed
    Jul 20, 2026
    Evidence
    12
    Source links
    4
  2. AR-RB-2026-02Competition Research Briefs

    Research brief / United States

    Five Digital Gateways

    Five system histories, exact share rows, official product-attribution paths, and a public research agenda with every denominator kept separate.
    Published
    Jul 20, 2026
    Sources reviewed
    Jul 20, 2026
    Evidence
    5
    Source links
    5

Evidence systems

Questions, programs, datasets, and analysis routes

Every lane retains its own unit and source contract.

Research agenda

12 bounded questions
  1. SharesWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Browsers / Four-participant concentration ratio
  2. MechanismWhich entry, exit, share, switching, price, quality, or capacity evidence can explain the movement inside this exact market boundary?Browsers / Herfindahl-Hirschman Index
  3. SharesWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Browsers / Leading-participant share
  4. SharesWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Mobile operating systems / Four-participant concentration ratio
  5. MechanismWhich entry, exit, share, switching, price, quality, or capacity evidence can explain the movement inside this exact market boundary?Mobile operating systems / Herfindahl-Hirschman Index
  6. SharesWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Mobile operating systems / Leading-participant share
  7. SharesWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Search engines / Four-participant concentration ratio
  8. MechanismWhich entry, exit, share, switching, price, quality, or capacity evidence can explain the movement inside this exact market boundary?Search engines / Herfindahl-Hirschman Index
Show 4 more questions
  1. SharesWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Search engines / Leading-participant share
  2. SharesWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Social referrals / Four-participant concentration ratio
  3. MechanismWhich entry, exit, share, switching, price, quality, or capacity evidence can explain the movement inside this exact market boundary?Social referrals / Herfindahl-Hirschman Index
  4. SharesWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Social referrals / Leading-participant share

Issue programs

1 editorial program
  1. 105 evidence linksDigital platform gatewaysHow do defaults, distribution agreements, data access, and adjacent-platform positions shape entry across separately measured digital systems?

Public datasets

9 reusable contracts
  1. 12 rows / 38 fieldsMarket profilesProfile-level market definitions, exact concentration measures, source custody, and deterministic public-interest briefs that keep structure, change, evidence gaps, and action questions separate.
  2. 12 rows / 9 fieldsMarket definitionsStructured product boundaries, geographies, denominators, inclusions, exclusions, metric families, and permitted comparison uses.
  3. 162 rows / 8 fieldsParticipant sharesFirm, product, service, or aggregate share observations used for top-participant, CR4, and source-coverage calculations.
  4. 20 rows / 10 fieldsOperator label indexOfficial operator labels joined to product participants and separately defined market footprints with ownership and comparison guardrails.
  5. 28 rows / 9 fieldsOperator attribution edgesOne inspectable official attribution record per product label with operator, evidence type, source URL, access date, and market handoffs.
  6. 65 rows / 16 fieldsMarket trend seriesDefinition-aware HHI, CR4, and leading-participant anchors with normalization baselines, source custody, and comparison guardrails.
  7. 105 rows / 29 fieldsHHI change decompositionParticipant-level share-squared contributions for adjacent, definition-stable market releases, with residual-firm assumptions, possible HHI-change bounds, endpoint classifications, source custody, and non-causal guardrails.
  8. 14 rows / 16 fieldsPolicy eventsOfficial complaints, decisions, inquiries, remedies, reports, and settlements joined to the markets they contextualize and to one explicitly declared proceeding chronology.
  9. 31 rows / 11 fieldsNamed policy-record edgesOne inspectable official-record relationship per named organization, with role, event stage, market context, source custody, and inference guardrails.

Analysis routes

5 declared handoffs
  1. 01 / profilePlatform systemsFive separate usage and referral screens
  2. 02 / researchDigital gateways programDefaults, access, and entry research
  3. 03 / dataOperator connectionsOfficial product attribution evidence
  4. 04 / compareCompare operatorsTwo-to-four attribution footprints
  5. 05 / researchOfficial recordsNamed public enforcement records
Topic collection citation

Antitrust Radar. (2026). Digital Platforms [Research topic]. Antitrust Radar.

Open publication citations