Public competition desk

U.S. competition observatory

A one-page view of concentration across markets, where the evidence is missing, and which firms are connected. Use the underlying sources to investigate questions, not to infer a legal violation from a score.

12 markets45 sources4 HHI gaps

Observatory indexChoose the evidence universe

4 public domains

Research desk

See who holds markets and where

Read firm-share structure beside state conditions, sector signals, and auditable market rows.

12in view0filters17sources

Refine market sliceSector, geography, concentration, vintage, status, and confidenceAll markets12 in view

Market structure

Who holds each market

Tiles are sized by sourced firm-level share. Switch markets to see concentration as structure, not just a single HHI number.

Browse all markets

Defined market

U.S. domestic airline passengers

Transportation · United States

Classification withheld

HHI

Withheld

Not firm-level

Top firm

17.8%

Largest share

CR4

69.0%

Top 4 firms

2026periodBureau of Transportation Statisticssource10sourced firms

Reusable evidence packetDomestic airlines5 routes

Profilefull market dossier Source rows1 linked source Market JSONmachine-readable row Data consolescoped API workbench Action briefturn signal into ask

Open full profile

Cross-system state atlas

Two markets, one geography, no composite score.

Compare individual-insurance concentration with a reproducible statewide FDIC branch-deposit screen, then inspect the exact state record behind either layer.

Systems: 2
States: 51
Rows: 102
Sources: 2

Paired relationship plane

Insurance HHI x statewide bank-deposit HHI

Selected jurisdictionDelawareDEPaired readingsInsurance 5,925Banking 4,967Evidence handoffSouthInspector active

MidwestNortheastSouthWestPearson r 0.247 / descriptive only

5Both above31Insurance only0Banking only15Both below

Threshold cohort / 5 jurisdictions

Both systems above 2,500

Threshold-defined cohort in alphabetical order; both exact readings remain separate and are not combined.

Selected jurisdiction / South

Delaware

DE / two bounded systems

FDIC / 2025

Bank-deposit HHI

4,967#1 / 51

Highly concentrated statewide deposit screen.

Leading holder: 67.8%
Deposits: $538.5B
Organizations: 30
Branches: 217

Largest reported holder: Capital One Financial Corporation

KFF / 2024

Individual-insurance HHI

5,925#4 / 51

Leader 75% / 3 insurers above 5%.

Open state evidence profile

FDIC dossier KFF dossier

FDIC source KFF source

Sector priority board

Where concentration becomes policy work

Sectors are ranked by public HHI signals, data completeness, and the next public-interest action needed to keep markets fair.

Sectors

Profiles

Review

Gaps

Digital platforms

4 market profiles

Priority review

5,624

Avg HHI

High

Gaps

HHI intensity5,624

Profile coverage4

Public action

Prioritize agency review

High concentration should move toward agency questions and remedy review.

Focus this sector

Health insurance

1 market profile

Priority review

3,650

Avg HHI

High

Gaps

HHI intensity3,650

Profile coverage1

Public action

Prioritize agency review

High concentration should move toward agency questions and remedy review.

Focus this sector

Software

1 market profile

Priority review

3,612

Avg HHI

High

Gaps

HHI intensity3,612

Profile coverage1

Public action

Prioritize agency review

High concentration should move toward agency questions and remedy review.

Focus this sector

Telecommunications

2 market profiles

Priority review

2,526

Avg HHI

High

Gaps

HHI intensity2,526

Profile coverage2

Public action

Prioritize agency review

High concentration should move toward agency questions and remedy review.

Focus this sector

Food and agriculture

1 market profile

Evidence build

Pending

Avg HHI

High

Gaps

HHI intensityN/A

Profile coverage1

Public action

Publish reusable firm-level data

Missing public data should be converted into disclosure asks.

Focus this sector

Health care

1 market profile

Evidence build

Pending

Avg HHI

High

Gaps

HHI intensityN/A

Profile coverage1

Public action

Publish reusable firm-level data

Missing public data should be converted into disclosure asks.

Focus this sector

Real estate

1 market profile

Evidence build

Pending

Avg HHI

High

Gaps

HHI intensityN/A

Profile coverage1

Public action

Publish reusable firm-level data

Missing public data should be converted into disclosure asks.

Focus this sector

Transportation

1 market profile

Evidence build

Pending

Avg HHI

High

Gaps

HHI intensityN/A

Profile coverage1

Public action

Publish reusable firm-level data

Missing public data should be converted into disclosure asks.

Focus this sector

Markets at a glance

Only sourced metrics are shown in ranking views.

Each row is a public evidence packet: exact metrics, source status, data freshness, action cue, and a machine-readable route. No composite score is used; signal basis lists the published metric flags behind each cue.

ranked rows

high concern

data gaps

source-backed

Rank	Market	HHI	CR4	Top firm	Class	Signal basis	Evidence	Action
1	U.S. mobile wireless service Telecommunications · United States 1 source	3,550	N/A	N/A	Highly concentrated	HHI >= 2,500 HHI +444 since 2017	Verified Federal Communications Commission Reviewed May 16, 2026 Open rows	Investigate Probe entry barriers, switching costs, pricing, and remedies.
2	U.S. residential fixed broadband access Telecommunications · United States / separately reported state, county, and census-tract summaries 1 source	1,501	N/A	N/A	Moderately concentrated	HHI +330 since 2020	Verified Federal Communications Commission Reviewed Jul 21, 2026 Open rows	Monitor Watch consolidation before public data goes stale.
3	U.S. domestic airline passengers Transportation · United States 1 source	Withheld	69.0%	17.8%	Not calculated	HHI withheld CR4 >= 60% Data incomplete	Incomplete Bureau of Transportation Statistics Reviewed May 16, 2026 Open rows	Disclose data Request firm-level shares and reusable public tables.
4	U.S. rental housing access Real estate · United States / local housing markets 4 sources	Withheld	N/A	N/A	Not calculated	HHI withheld Data incomplete	Incomplete Harvard Joint Center for Housing Studies Reviewed Jun 21, 2026 Open rows	Disclose data Request firm-level shares and reusable public tables.
5	U.S. search engine usage Digital platforms · United States 1 source	7,359	99.4%	85.2%	Highly concentrated	HHI >= 2,500 CR4 >= 60% Top firm >= 35%	Public estimate StatCounter Global Stats Reviewed Jul 17, 2026 Open rows	Investigate Probe entry barriers, switching costs, pricing, and remedies.
6	U.S. browser usage Software · United States 1 source	3,612	93.8%	50.0%	Highly concentrated	HHI >= 2,500 CR4 >= 60% Top firm >= 35%	Public estimate StatCounter Global Stats Reviewed Jul 17, 2026 Open rows	Investigate Probe entry barriers, switching costs, pricing, and remedies.
7	U.S. pharmacy benefit management Health care · United States 1 source	Withheld	N/A	N/A	Not calculated	HHI withheld Data incomplete	Incomplete Federal Trade Commission Reviewed May 16, 2026 Open rows	Disclose data Request firm-level shares and reusable public tables.
8	U.S. generative AI assistant usage Digital platforms · United States 1 source	4,804	94.8%	67.1%	Highly concentrated	HHI >= 2,500 CR4 >= 60% Top firm >= 35%	Public estimate StatCounter Global Stats Reviewed Jun 23, 2026 Open rows	Investigate Probe entry barriers, switching costs, pricing, and remedies.
9	U.S. steer and heifer purchases by beef packers Food and agriculture · United States / regional cattle procurement markets 3 sources	Withheld	N/A	N/A	Not calculated	HHI withheld Data incomplete	Incomplete U.S. Department of Agriculture Economic Research Service Reviewed Jul 19, 2026 Open rows	Disclose data Request firm-level shares and reusable public tables.
10	U.S. mobile operating-system web usage Digital platforms · United States 1 source	5,337	100.0%	63.1%	Highly concentrated	HHI >= 2,500 CR4 >= 60% Top firm >= 35% HHI +180 since 2023	Public estimate StatCounter Global Stats Reviewed Jul 20, 2026 Open rows	Investigate Probe entry barriers, switching costs, pricing, and remedies.
11	U.S. social-media referral traffic Digital platforms · United States 1 source	4,995	94.4%	68.9%	Highly concentrated	HHI >= 2,500 CR4 >= 60% Top firm >= 35% HHI +1,602 since 2023	Public estimate StatCounter Global Stats Reviewed Jul 20, 2026 Open rows	Investigate Probe entry barriers, switching costs, pricing, and remedies.
12	U.S. ACA individual health insurance Health insurance · United States / separately reported state and District of Columbia markets 1 source	3,650	N/A	N/A	Highly concentrated	HHI >= 2,500	Public estimate KFF Reviewed Jun 23, 2026 Open rows	Investigate Probe entry barriers, switching costs, pricing, and remedies.

#1 · Telecommunications

U.S. mobile wireless service

United States

HHI

3,550

CR4

N/A

Top firm

N/A

Signal basis

HHI >= 2,500
HHI +444 since 2017

Highly concentratedVerified metricInvestigate

Federal Communications Commission

1 source · reviewed May 16, 2026

Probe entry barriers, switching costs, pricing, and remedies.

Profile

Reuse evidenceCite · API · files

JSON CSV

#2 · Telecommunications

U.S. residential fixed broadband access

United States / separately reported state, county, and census-tract summaries

HHI

1,501

CR4

N/A

Top firm

N/A

Signal basis

HHI +330 since 2020

Moderately concentratedVerified metricMonitor

Federal Communications Commission

1 source · reviewed Jul 21, 2026

Watch consolidation before public data goes stale.

Profile

Reuse evidenceCite · API · files

JSON CSV

#3 · Transportation

U.S. domestic airline passengers

United States

HHI

Withheld

CR4

69.0%

Top firm

17.8%

Signal basis

HHI withheld
CR4 >= 60%
Data incomplete

Not calculatedIncomplete dataDisclose data

Bureau of Transportation Statistics

1 source · reviewed May 16, 2026

Request firm-level shares and reusable public tables.

Profile

Reuse evidenceCite · API · files

JSON CSV

Show 9 more ranked markets

#4 · Real estate

U.S. rental housing access

United States / local housing markets

HHI

Withheld

CR4

N/A

Top firm

N/A

Signal basis

HHI withheld
Data incomplete

Not calculatedIncomplete dataDisclose data

Harvard Joint Center for Housing Studies

4 sources · reviewed Jun 21, 2026

Request firm-level shares and reusable public tables.

Profile

Reuse evidenceCite · API · files

JSON CSV

#5 · Digital platforms

U.S. search engine usage

United States

HHI

7,359

CR4

99.4%

Top firm

85.2%

Signal basis

HHI >= 2,500
CR4 >= 60%
Top firm >= 35%

Highly concentratedEstimated from public dataInvestigate

StatCounter Global Stats

1 source · reviewed Jul 17, 2026

Probe entry barriers, switching costs, pricing, and remedies.

Profile

Reuse evidenceCite · API · files

JSON CSV

#6 · Software

U.S. browser usage

United States

HHI

3,612

CR4

93.8%

Top firm

50.0%

Signal basis

HHI >= 2,500
CR4 >= 60%
Top firm >= 35%

Highly concentratedEstimated from public dataInvestigate

StatCounter Global Stats

1 source · reviewed Jul 17, 2026

Probe entry barriers, switching costs, pricing, and remedies.

Profile

Reuse evidenceCite · API · files

JSON CSV

#7 · Health care

U.S. pharmacy benefit management

United States

HHI

Withheld

CR4

N/A

Top firm

N/A

Signal basis

HHI withheld
Data incomplete

Not calculatedIncomplete dataDisclose data

Federal Trade Commission

1 source · reviewed May 16, 2026

Request firm-level shares and reusable public tables.

Profile

Reuse evidenceCite · API · files

JSON CSV

#8 · Digital platforms

U.S. generative AI assistant usage

United States

HHI

4,804

CR4

94.8%

Top firm

67.1%

Signal basis

HHI >= 2,500
CR4 >= 60%
Top firm >= 35%

Highly concentratedEstimated from public dataInvestigate

StatCounter Global Stats

1 source · reviewed Jun 23, 2026

Probe entry barriers, switching costs, pricing, and remedies.

Profile

Reuse evidenceCite · API · files

JSON CSV

#9 · Food and agriculture

U.S. steer and heifer purchases by beef packers

United States / regional cattle procurement markets

HHI

Withheld

CR4

N/A

Top firm

N/A

Signal basis

HHI withheld
Data incomplete

Not calculatedIncomplete dataDisclose data

U.S. Department of Agriculture Economic Research Service

3 sources · reviewed Jul 19, 2026

Request firm-level shares and reusable public tables.

Profile

Reuse evidenceCite · API · files

JSON CSV

#10 · Digital platforms

U.S. mobile operating-system web usage

United States

HHI

5,337

CR4

100.0%

Top firm

63.1%

Signal basis

HHI >= 2,500
CR4 >= 60%
Top firm >= 35%
HHI +180 since 2023

Highly concentratedEstimated from public dataInvestigate

StatCounter Global Stats

1 source · reviewed Jul 20, 2026

Probe entry barriers, switching costs, pricing, and remedies.

Profile

Reuse evidenceCite · API · files

JSON CSV

#11 · Digital platforms

U.S. social-media referral traffic

United States

HHI

4,995

CR4

94.4%

Top firm

68.9%

Signal basis

HHI >= 2,500
CR4 >= 60%
Top firm >= 35%
HHI +1,602 since 2023

Highly concentratedEstimated from public dataInvestigate

StatCounter Global Stats

1 source · reviewed Jul 20, 2026

Probe entry barriers, switching costs, pricing, and remedies.

Profile

Reuse evidenceCite · API · files

JSON CSV

#12 · Health insurance

U.S. ACA individual health insurance

United States / separately reported state and District of Columbia markets

HHI

3,650

CR4

N/A

Top firm

N/A

Signal basis

HHI >= 2,500

Highly concentratedEstimated from public dataInvestigate

KFF

1 source · reviewed Jun 23, 2026

Probe entry barriers, switching costs, pricing, and remedies.

Profile

Reuse evidenceCite · API · files

JSON CSV