Antitrust Radar

Competition issue dossier

Digital platform gateways

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

Search, browsers, mobile operating systems, social referrals, and generative AI assistants are tracked as separate usage-share proxies while the issue program follows their declared product, operator, and official-record links.

Inspect evidence Compare Atlas JSON CSV
Bounded markets5
Evidence routes105
Official records4
Source custody9
Updated through2026-07-20
Interpretation boundaryIssue program, not market definition

The five usage and referral profiles have distinct denominators and boundaries. Their placement in one issue program supports navigation and research design, not cross-market share addition or a combined market definition.

Use standard

01 / Bounded market screens

Keep each measure inside its declared universe.

5 market profiles remain separate inside this issue program. Census rows are navigation context, not substitutes.

Digital platforms

U.S. search engine usage

United States / 2026

HHI7,359CR499.4%Top share85.2%EvidenceEstimated Publicmedium confidence
Software

U.S. browser usage

United States / 2026

HHI3,612CR493.8%Top share50.0%EvidenceEstimated Publicmedium confidence
Digital platforms

U.S. mobile operating-system web usage

United States / 2026

HHI5,337CR4100.0%Top share63.1%EvidenceEstimated Publicmedium confidence
Digital platforms

U.S. social-media referral traffic

United States / 2026

HHI4,995CR494.4%Top share68.9%EvidenceEstimated Publicmedium confidence
Digital platforms

U.S. generative AI assistant usage

United States / 2026

HHI4,804CR494.8%Top share67.1%EvidenceEstimated Publicmedium confidence
Census navigation context3 declared six-digit screens
NAICS 518210Computing infrastructure providers, data processing, web hosting, and related servicesHHI Withheld / CR4 37.2% / 12,054 firmsNAICS 513210Software publishersHHI Withheld / CR4 24.3% / 16,824 firmsNAICS 519290Web search portals and all other information servicesHHI Withheld / CR4 89.6% / 1,004 firms

02 / Research program

Turn the issue frame into testable evidence requests.

Program questions are editorial research designs. Canonical dossiers appear only where the observatory has a definition-stable latest-to-prior signal.

Program questions

  1. 01

    Which distribution agreements and default placements affect switching at each gateway?

  2. 02

    Where do data, compute, interoperability, or access conditions constrain entry without assuming the same mechanism across products?

  3. 03

    Which firm-level and user-level records can separate usage movement from changes in product quality, availability, or measurement?

Observed change

Canonical signal questions

12
Browsers / Four-participant concentration ratioWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Share accounting / observed direction: increasedBrowsers / Herfindahl-Hirschman IndexWhich entry, exit, share, switching, price, quality, or capacity evidence can explain the movement inside this exact market boundary?Market mechanism / observed direction: decreasedBrowsers / Leading-participant shareWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Share accounting / observed direction: decreasedMobile operating systems / Four-participant concentration ratioWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Share accounting / observed direction: increasedMobile operating systems / Herfindahl-Hirschman IndexWhich entry, exit, share, switching, price, quality, or capacity evidence can explain the movement inside this exact market boundary?Market mechanism / observed direction: increasedMobile operating systems / Leading-participant shareWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Share accounting / observed direction: increasedSearch engines / Four-participant concentration ratioWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Share accounting / observed direction: decreasedSearch engines / Herfindahl-Hirschman IndexWhich entry, exit, share, switching, price, quality, or capacity evidence can explain the movement inside this exact market boundary?Market mechanism / observed direction: decreasedSearch engines / Leading-participant shareWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Share accounting / observed direction: decreasedSocial referrals / Four-participant concentration ratioWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Share accounting / observed direction: decreasedSocial referrals / Herfindahl-Hirschman IndexWhich entry, exit, share, switching, price, quality, or capacity evidence can explain the movement inside this exact market boundary?Market mechanism / observed direction: increasedSocial referrals / Leading-participant shareWhich participant-share changes account for the structural movement, and are the denominator and coverage stable across both anchors?Share accounting / observed direction: increased

03 / Participants and attribution

Separate source labels from operator evidence.

Participant shares apply only to their source, year, and market. Operator links rely on separate official attribution records and do not establish a complete ownership graph.

Measured rows

Source-labeled participants

36
Google SearchProduct / 1 market85.2%FacebookProduct / 1 market68.9%ChatGPTProduct / 1 market67.1%iOSProduct / 1 market63.1%ChromeProduct / 1 market50.0%AndroidProduct / 1 market36.9%SafariProduct / 1 market31.9%Twitter / XProduct / 1 market11.6%Google GeminiProduct / 1 market10.9%Microsoft CopilotProduct / 1 market10.8%BingProduct / 1 market9.8%EdgeProduct / 1 market8.1%PinterestProduct / 1 market7.5%InstagramProduct / 1 market6.3%ClaudeProduct / 1 market6.0%PerplexityProduct / 1 market5.2%FirefoxProduct / 1 market3.8%BraveProduct / 1 market2.7%Yahoo SearchProduct / 1 market2.7%RedditProduct / 1 market2.4%YouTubeProduct / 1 market2.3%DuckDuckGoProduct / 1 market1.7%Samsung InternetProduct / 1 market1.4%LinkedInProduct / 1 market0.40%YandexProduct / 1 market0.38%TumblrProduct / 1 market0.29%FarkProduct / 1 market0.16%EcosiaProduct / 1 market0.11%Hacker NewsProduct / 1 market0.09%DeepSeekProduct / 1 market0.05%SamsungProduct / 1 market0.05%KaiOSProduct / 1 market0.02%LinuxProduct / 1 market0.00%SymbianOSProduct / 1 market0.00%VKontakteProduct / 1 market0.00%Windows PhoneProduct / 1 market0.00%

5 aggregate or residual categories are excluded from the firm count and retained in the public packet.

Separate evidence

Official operator attributions

20
Anthropic1 product / 1 official attributionApple2 products / 2 official attributionsBrave Software1 product / 1 official attributionDeepSeek1 product / 1 official attributionDuckDuckGo1 product / 1 official attributionEcosia1 product / 1 official attributionGoogle5 products / 5 official attributionsLinkedIn1 product / 1 official attributionMeta2 products / 2 official attributionsMicrosoft3 products / 3 official attributionsMozilla Corporation1 product / 1 official attributionOpenAI1 product / 1 official attributionPerplexity AI1 product / 1 official attributionPinterest1 product / 1 official attributionReddit Inc.1 product / 1 official attributionSamsung Electronics1 product / 1 official attributionTumblr1 product / 1 official attributionX Corp.1 product / 1 official attributionYahoo1 product / 1 official attributionYandex1 product / 1 official attribution

04 / Official record

Read chronology and named organizations as separate evidence.

4 dated records and 6 exact organization labels; no liability or causal inference is added.

U.S. District Court for the District of Columbia / Remedy

Court orders search distribution and data-access remedies

The court prohibited specified exclusive distribution contracts and ordered access to certain search index and user-interaction data plus search and text-ad syndication services.Open record

Federal Trade Commission / Monitoring

FTC reports on cloud-provider and generative AI partnerships

The FTC published findings from its Section 6(b) study of investments and partnerships involving Alphabet, Amazon, Microsoft, Anthropic, and OpenAI.Open record

U.S. District Court for the District of Columbia / Decision

Court finds Google liable for unlawful search monopoly maintenance

The district court issued a liability opinion finding that Google maintained monopolies in general search services and general search text advertising in violation of Section 2 of the Sherman Act.Open record

U.S. Department of Justice / Litigation

United States files search monopolization complaint against Google

DOJ and state plaintiffs filed a civil case challenging Google's maintenance of monopolies in general search services and search advertising through distribution agreements.Open record
Exact labels

Named organizations

6

Competition issues are editorial navigation programs assembled from exact public-record links. An issue grouping is not a legal product or geographic market, does not make unlike concentration measures comparable, and does not establish ownership, control, liability, competitive harm, or causality.