Market concentration rankings

Compare published concentration measures, changes, and data gaps within their stated market definitions. Rankings help identify research questions; they do not rank legal violations.

Open workbench View table

Ranked rows

Data gaps

Tracked markets

all sectors

Source-backed

public rows

Disclosure gaps

active lens

Active lens route

Leading signal: Domestic airlines. 4 source-backed rows route to public action: disclose gaps.

Data gaps

LensData gaps4 ranked rows Top signalDomestic airlinesincomplete · high confidence Evidence4 backedincomplete ActionDisclose gapsDomestic airlines

PlotTop 5 Table4 rows ScatterCompare Network4 backed TreemapFirms APIJSON

Leading signals

Exact values under the active ranking lens.

Data gaps

Evidence · 4 rows Disclose gaps

Rank by

Highest HHI8 Top-firm share6 CR46 Increasing concentration4 Data gaps4

Public-interest screen

Data gaps

The active ranking connects concentration metrics to source status, market definition, and government action questions.

PlotTop 5exact ranking Table4 rowsranked leaders ScatterComparemarket lens Network4 backedsource route TreemapFirmsshare structure APIJSONpublic rows

Ranked distribution

Leading markets under data gaps

4 rows · exact values

Lens distribution

4 rows

Source-backed4rows with public evidence High concern1HHI, CR4, or top-firm flags Disclosure gaps4missing or low-confidence facts Public queue4Disclose gaps

Data gaps

Markets ordered by observable disclosure need: unavailable or incomplete records, low confidence, then withheld HHI.

4 markets match this lens; leading signal: Domestic airlines with incomplete · high confidence.

Evidence packet

U.S. domestic airline passengers

Transportation · United States

HHI

Withheld

CR4

69.0%

Top firm

17.8%

Source basis: Bureau of Transportation Statistics.

Public-use route

Copy the citation line or filtered market API endpoint for notes, notebooks, and reproducible research.

JSON CSV

Open market profile

Government action path

1Publish market-share tables

2Explain entry and switching barriers

3Tie remedies to prices, choice, quality, and access

Research desk

Move from screen to evidence.

Ranking4 ranked rows

HHI8 marketsOpen Top firm6 marketsOpen CR46 marketsOpen Rising4 marketsOpen Data gaps4 marketsActive

Source-backed onlyAbout rankings

Ranking workbench

Find the market behind the signal.

4 of 4 markets match this lens after search and evidence filters.

Data gaps ranking

Markets ordered by observable disclosure need: unavailable or incomplete records, low confidence, then withheld HHI.

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 #1

Domestic airlines

Transportation

Disclose data

HHI

Withheld

CR4

69.0%

Top firm

17.8%

Bureau of Transportation Statistics

1 source · reviewed May 16, 2026

Profile Open data

Rank #2

PBMs

Health care

Disclose data

HHI

Withheld

CR4

N/A

Top firm

N/A

Federal Trade Commission

1 source · reviewed May 16, 2026

Profile Open data

Rank #3

Rental housing

Real estate

Disclose data

HHI

Withheld

CR4

N/A

Top firm

N/A

Harvard Joint Center for Housing Studies

4 sources · reviewed Jun 21, 2026

Profile Open data

Rank	Market	HHI	CR4	Top firm	Class	Signal basis	Evidence	Action
1	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 Reuse evidence JSON CSV	Disclose data Request firm-level shares and reusable public tables.
2	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 Reuse evidence JSON CSV	Disclose data Request firm-level shares and reusable public tables.
3	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 Reuse evidence JSON CSV	Disclose data Request firm-level shares and reusable public tables.
4	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 Reuse evidence JSON CSV	Disclose data Request firm-level shares and reusable public tables.

#1 · 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

#2 · 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

#3 · 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

#4 · 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

Reusable ranking packet

Data gaps

Export the current public filters as JSON, CSV, or a data-console route so ranking claims can move into notes, notebooks, and public action.

Data gaps

lens rows

source backed

api filters

The packet uses the same structured filters available in the public API grammar.

View lensranking page Markets JSONfiltered rows CSV exportspreadsheet-ready Data consolesame filters Action queueDomestic airlines

Compare markets

Outlier lens: Data gaps

Markets ordered by observable disclosure need: unavailable or incomplete records, low confidence, then withheld HHI.

Selected

Highest HHI

Withheld

Data gaps

Cross-market definition guardrail

The same 0-10,000 HHI scale does not make different product, geographic, or denominator definitions economically interchangeable. Cross-market HHI is a descriptive screen only.

Inspect definitions

Selected markets

Domestic airlines

Evidence packets

1 public source

Disclosure pressure

1 data gap visible

Action queue

Disclose

Research handoff

Comparison packet ready.

Selected evidence packets

Domestic airlines
Transportation
Disclose
HHI
Withheld
CR4
69%
Top
17.8%
Profile Data
Reusable route
HHI is withheld under the carrier share of domestic scheduled passengers basis; use 1 public source to frame a disclosure ask.
Agency defined · Not comparable · Snapshot only
JSON Definition
Action route

The plot uses sourced HHI when available and keeps withheld-HHI markets on a visible data-gap rail instead of inventing shares.

Historical release lab

Market ranking time machine

Compare exact sourced release frames. Missing markets stay absent, and rank movement is measured against the prior published frame without interpolation or carry-forward.

Open figure

Release frame

2026

HHI

Observed markets

5/12

tracked universe

Prior release

2025

4 shared markets

Universe change

+1 / -0

5 sources

Exact 2026 frame

Herfindahl-Hirschman Index

Source-reported or reproducibly calculated HHI anchors.

5 released

Rank roseRank fellEntered frameRanks use only observed rows in each release.

Selected release row

Search engines

Digital platforms / 2026

Estimated Public

Rank: #1
HHI: 7,359
Movement: Held
Confidence: Medium

Source custody

StatCounter Global Stats

Search engine market share in United States of America April 2026

-230 HHI since prior release

HHI is computed from listed StatCounter percentages and a small residual Other category equal to 100 minus listed shares.

Market profile Exact figure Source profile Source release

Cross-release cohort

Market rank trajectories

Follow a chosen cohort through the full observed ranking universe in each exact release. Rank denominators can change as markets enter or leave a published frame.

Cohort markets

4 selected / 5 maximum

Minimum 2; ranks retain every observed market in the release.

AI assistants1 release / through 2026Browsers4 releases / through 2026Fixed broadband5 releases / through 2024Individual insurance1 release / through 2024Mobile operating systems4 releases / through 2026Search engines4 releases / through 2026Social referrals4 releases / through 2026Wireless service3 releases / through 2023

Release frames

42023-2026

Cohort anchors

164 selected markets

Explicit gaps

0no fill or carry-forward

Source releases

44 complete series

Global rank / exact releases

Herfindahl-Hirschman Index

Cursor 2026

2026 release row

Search engines

Digital platforms

Global rank: #1 / 5
HHI: 7,359
Movement: Held
Evidence: Medium

Source custody

StatCounter Global StatsSearch engine market share in United States of America April 2026

HHI is computed from listed StatCounter percentages and a small residual Other category equal to 100 minus listed shares.

Market profile Source release

Release rule

Each rank is recalculated from every observed market in that exact metric release. Missing observations remain absent.

Definition rule

Product boundaries, geographies, and source scopes remain distinct. Rank movement is a research screen, not a legal market conclusion.

Public interest triage

Public action queue: Data gaps

Rankings shouldn’t stop at naming concentrated markets. This queue turns the active lens into a public-interest docket for data disclosure, investigation, and remedy design.

Queue order uses the review category, latest sourced HHI, and visible trigger count. It does not estimate consumer harm or establish legal liability.

Immediate

Near-term

Data gaps

Agency-ready

Open advocacy agenda Audit sources

#1Evidence buildTop firm 17.8%
Domestic airlines
Transportation · United States · high confidence · incomplete
2
exact flags
Review basis
69.0% CR4 (>= 60%)Public data incomplete
Public action
Publish firm-level shares, ownership/control links, and market-definition notes before public agencies rely on private estimates.
Evidence needed
Firm-level shares and local ownership/control data
#2Evidence buildPublic data gap
Beef meatpacking
Food and agriculture · United States / regional cattle procurement markets · high confidence · incomplete
1
exact flags
Review basis
Public data incomplete
Public action
Publish firm-level shares, ownership/control links, and market-definition notes before public agencies rely on private estimates.
Evidence needed
Firm-level shares and local ownership/control data
#3Evidence buildPublic data gap
PBMs
Health care · United States · high confidence · incomplete
1
exact flags
Review basis
Public data incomplete
Public action
Publish firm-level shares, ownership/control links, and market-definition notes before public agencies rely on private estimates.
Evidence needed
Firm-level shares and local ownership/control data
#4Evidence buildPublic data gap
Rental housing
Real estate · United States / local housing markets · medium confidence · incomplete
1
exact flags
Review basis
Public data incomplete
Public action
Publish firm-level shares, ownership/control links, and market-definition notes before public agencies rely on private estimates.
Evidence needed
Firm-level shares and local ownership/control data