Business Associations (U.S.) — NAICS 81391

An investor's primer for a general audience — public and private.

Read this first — single-child level. NAICS industry 81391 Business Associations is a "pass-through": it contains exactly one national industry, 813910 Business Associations, and nothing else. The two codes cover the same establishments and carry the same federal statistics. This page is a short orientation to the level as a whole. For the full treatment — the investable ecosystem, how the money works, regulation, consolidation, and risks — read the 813910 primer.

1. Overview

The North American Industry Classification System (NAICS) is the U.S. government's standard scheme for grouping businesses. It nests from broad to narrow, and 81391 is a five-digit "NAICS industry." Below it sits a single six-digit "national industry," 813910, which is identical in scope.

The level covers the collective self-organization of an industry: chambers of commerce, trade associations, real estate boards, farm bureaus, and manufacturers' and growers' groups. These are membership bodies whose members are companies (and sometimes individual practitioners), and whose job is to advance the members' shared commercial interests — lobbying legislators, setting voluntary standards, running trade shows, publishing research, and certifying practitioners.[1]

The distinctive feature to grasp up front: this is largely a nonprofit field with no owners and no equity. Most business associations are organized under Section 501(c)(6) of the Internal Revenue Code (IRC) — "business leagues" — which means they pay no federal income tax on core activities, have no shareholders, and reinvest any surplus rather than distributing profit.[2] You cannot buy a share of the National Association of Realtors (NAR) or the U.S. Chamber of Commerce. For an investor, exposure comes only from the for-profit ecosystem that runs on top of the associations — events, software, media, data, and outsourced management.

2. What's inside — and why the level equals its one child

NAICS breaks 81391 into exactly one child:

When a five-digit NAICS industry has a single six-digit child, the two are definitionally the same set of establishments — the extra digit adds no further subdivision. So every figure, every company, and every dynamic at 81391 is 813910. There is no allocation to make and no second segment to compare against. This page therefore stays short and hands off the detail to the child primer.

3. How big it is (this level's rollup figures)

Because the level equals its one child, these ground-truth federal figures apply to both. All are drawn from our ingested statistics for 81391 (U.S. Census Bureau and U.S. Small Business Administration, SBA):

The picture is of a small-unit, exceptionally fragmented field. The average establishment runs roughly seven employees and about $2 million of receipts (the receipts figure is 2022 and employment is 2023, so don't read the two as one income statement), yet average pay is high — about $99,000 ($10.442bn payroll ÷ 105,286 employees) — reflecting concentrations of professional lobbyists, executives, and policy staff in Washington and state capitals.[3] The four largest firms take just 6.5% of receipts (CR4), the top 50 only 24.5% (CR50), and the HHI — a standard concentration gauge where 10,000 is a monopoly — is 20, among the lowest readings of any U.S. industry.[4] Thousands of local chambers and niche trade groups sit alongside a handful of large national bodies.

Undercount caveat — read before quoting the $30 billion. Three things pull the true footprint above the headline: (1) receipts measure the associations' own operating budgets (dues plus program revenue), not the far larger commerce and regulation they influence; (2) when a for-profit association management company (AMC) or event firm actually runs an association, much of the real activity is booked under management-services or trade-show codes, not here; and (3) County Business Patterns (CBP) counts only employer establishments with paid staff, so tiny all-volunteer chambers and non-employer bodies fall below the reporting threshold, and the Economic Census excludes government establishments.[6] Our stats file also carries no national figures for membership, renewal rates, dues mix, or event economics — those must come from individual filings.

4. Where value concentrates (investable universe)

With one child, all investable value sits in that same layer — and none of it is the associations themselves, which are nonprofits with no equity. Value concentrates in the for-profit ecosystem around them:

• Events and exhibitions — the cleanest listed exposure, because trade shows are the associations' single largest non-dues revenue line. Informa PLC (London Stock Exchange: INF) and RELX PLC (LSE: REL / New York Stock Exchange: RELX) are the global majors; GL events (Euronext Paris: GLO) is a European-listed integrated operator.[20][21][22]
• Alternative-asset managers — Apollo Global Management (NYSE: APO) and Blackstone (NYSE: BX) hold private event, software, and services businesses (Emerald, Clarion, Cvent) through their funds.[23][25][26]
• Private operators — AMCs (SmithBucklin, Kellen, MCI), event and experiential firms (Freeman, Global Experience Specialists), and association-management-software (AMS) platforms (Momentive Software) are largely private and consolidating.

The largest associations themselves — PhRMA (~$521m), NAR (~$361m), the American Petroleum Institute (~$252m), the U.S. Chamber (~$226m) — are shown for scale in the child primer, not as investments.[11][12][13][14] See 813910, Section 4 for the full universe.

5. How the money works

A business association's economics reduce to dues and non-dues revenue. Dues are recurring and usually tiered by member size; the key operating metrics are member count, retention/renewal rate, and dues yield per member. Non-dues revenue — historically a minority, now roughly half of income for many groups — comes chiefly from trade shows and conferences (registrations, booth fees, sponsorships), plus certification, data and benchmarking, publications, and affinity programs.[17]

Because these are 501(c)(6) nonprofits, the bottom line is a surplus, not a profit — excess revenue becomes reserves reinvested in the mission, with no dividend and no equity value to accrue. For the event and software companies that are investable, the metrics shift to exhibitor renewal and booth sell-through, attendee registrations, sponsorship bookings, deferred revenue, software churn, leverage, and free cash flow.[20][21] Full detail is in 813910, Section 5.

6. Demand drivers

• Size and health of the member industry — more companies means more potential members; consolidation shrinks the base.
• Regulatory and legislative threat — the counter-cyclical driver: members pay most for collective defense when new rules, taxes, or scrutiny rise. Federal lobbying hit a record $4.44 billion in 2024.[18]
• Standards and credentials — certification and training create durable, excludable member value.[1]
• The live-events economy — because trade shows fund so much of the sector, demand tracks business travel and marketing budgets.[21]
• Technology — cloud software, data, and artificial intelligence (AI) can lift retention, event monetization, and staff productivity.

7. Regulation

Business associations are lightly regulated as businesses but tightly watched in four areas: tax status (501(c)(6) exemption, unrelated business income tax, and the public Form 990)[2][7]; lobbying disclosure (federal Lobbying Disclosure Act plus state rules, and IRC Section 162(e), which makes the lobbying slice of dues nondeductible to members)[8]; election law (political spending generally routed through a separate political action committee under Federal Election Commission rules); and — the sharpest risk — antitrust, because an association is by design a gathering of competitors. That risk is not theoretical: in 2024 NAR agreed to pay $418 million and scrap its cooperative-commission rules to settle litigation that had produced a $1.8 billion jury verdict.[10][19] See 813910, Section 7.

8. Consolidation

Associations mostly don't compete for the same members — one industry tends to have one dominant trade group — so rivalry is over share of member wallet and relevance, not price, which is why the federal data show such extreme fragmentation (HHI of 20).[4] The consolidation that is happening runs through the for-profit layer: private-equity roll-ups of the events, software, and outsourced-management businesses that serve associations. Blackstone owns Clarion and Cvent; Truelink bought Global Experience Specialists; TA Associates built Momentive Software (which then acquired Personify); and Apollo is taking Emerald private.[23][25][26][20][21][22] The rationale is one cross-selling platform spanning membership management, events, learning, payments, content, and data.

9. Risks

• Member-base erosion — consolidation or decline of the underlying industry directly shrinks dues and event revenue.
• Antitrust and litigation — the NAR settlement shows association rules can produce nine- and ten-figure liabilities and forced structural change.[19]
• Event concentration and shock risk — heavy reliance on one or two annual trade shows is a single point of failure (the 2020 COVID-19 event shutdown is the template).[21]
• Commoditization — data, standards, and education once sold exclusively are now widely available; AI lowers the cost of producing research.
• Tax-status risk — aggressive commercial activity can jeopardize 501(c)(6) exemption or trigger tax.[2][7]
• On the investable side — private-equity leverage, integration risk, customer concentration, and control of member data.
• Measurement risk — federal data miss the volunteer, government, and non-employer tail, so top-down sizing is approximate.

10. How to invest and outlook

There is no direct way to invest in a business association — the level is nonprofit with no equity. Exposure comes only through the ecosystem: on the public side, event and information majors (Informa, RELX, GL events) and the alternative-asset managers (Apollo, Blackstone) whose funds own the private operators; on the private side, AMCs, event and venue-services firms, association-management software and payments, and trade media, data, and credentialing platforms.[20][21][22][23][25][26]

The near-term picture: record lobbying keeps advocacy demand firm; a post-NAR antitrust overhang raises legal cost and scrutiny of association rules; live business-to-business events have rebuilt past their pre-2020 base and are consolidating into a few large operators and PE platforms — the most direct way public investors participate.[18][19][20] The core level will remain a fragmented, nonprofit, member-governed field with no equity to buy; the opportunity is the for-profit layer on top of it.

For the complete analysis, see the child primer: NAICS 813910, Business Associations.

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Sources

1. U.S. Census Bureau, "2022 NAICS Search: 813910 Business Associations (definition, examples, and exclusions)," 2022. https://www.census.gov/naics/?details=813910&input=813910&year=2022
2. Internal Revenue Service, "Business Leagues (501(c)(6))," accessed 2026. https://www.irs.gov/charities-non-profits/other-non-profits/business-leagues
3. U.S. Census Bureau, County Business Patterns 2023, Table CB2300CBP (NAICS 813910: establishments, employment, annual and Q1 payroll) — Histometrics ingested federal statistics. https://data.census.gov/table/CBP2023.CB2300CBP?codeset=naics~813910
4. U.S. Census Bureau, 2022 Economic Census, Concentration of Largest Firms, Table EC2200SIZECONCEN (NAICS 813910: firms, receipts, CR4/CR8/CR20/CR50, HHI) — Histometrics ingested federal statistics. https://data.census.gov/table/ECNSIZE2022.EC2200SIZECONCEN?codeset=naics~813910
5. U.S. Small Business Administration, "Table of Small Business Size Standards," 2023 (NAICS 813910 = $15.5 million average annual receipts) — Histometrics ingested federal statistics. https://data.sba.gov/dataset/small-business-size-standards
6. U.S. Census Bureau, "County Business Patterns Methodology" (employer-establishment coverage; exclusions), accessed 2026. https://www.census.gov/programs-surveys/cbp/technical-documentation/methodology.html
7. Internal Revenue Service, "Instructions for Form 990" and "Unrelated Business Income Tax," 2025–2026. https://www.irs.gov/instructions/i990
8. Internal Revenue Service, "Nondeductible Lobbying and Political Expenditures" / IRC Section 162(e), accessed 2026. https://www.irs.gov/charities-non-profits/other-non-profits/nondeductible-lobbying-and-political-expenditures
9. U.S. Federal Trade Commission, "Spotlight on Trade Associations," accessed 2026. https://www.ftc.gov/advice-guidance/competition-guidance/guide-antitrust-laws/dealings-competitors/spotlight-trade-associations
10. ProPublica Nonprofit Explorer, "Pharmaceutical Research and Manufacturers of America — Form 990, FY2024," 2025. https://projects.propublica.org/nonprofits/organizations/530241211
11. ProPublica Nonprofit Explorer, "National Association of Realtors — Form 990, FY2024," 2025. https://projects.propublica.org/nonprofits/organizations/361520690
12. ProPublica Nonprofit Explorer, "American Petroleum Institute — Form 990, FY2024," 2025. https://projects.propublica.org/nonprofits/organizations/130433430
13. ProPublica Nonprofit Explorer, "Chamber of Commerce of the United States of America — Form 990, FY2024," 2025. https://projects.propublica.org/nonprofits/organizations/530045720
14. ASAE (American Society of Association Executives) / Avenue M Group, "Association revenue mix — dues vs. non-dues benchmarking," 2016–2017. https://www.asaecenter.org/resources/articles/an_magazine/2016/november-december/data-membership-dues-arent-the-only-revenue-stream
15. OpenSecrets, "Federal lobbying set new record in 2024 ($4.44 billion; top spenders NAR, U.S. Chamber)," 2025. https://www.opensecrets.org/news/2025/02/federal-lobbying-set-new-record-in-2024/
16. Fortune, "National Association of Realtors agrees to pay $418 million and lower fees to settle 'conspiracy' verdict," March 15, 2024. https://fortune.com/2024/03/15/nar-settles-lawsuits-real-estate-commissions-threat/
17. Informa PLC, "2025 Full-Year Results" (B2B Live Events revenue and 2026 guidance) and "Shareholder FAQs," 2026. https://www.informa.com/investors/
18. RELX PLC, "Annual Report 2025" (RX exhibitions division revenue, event count, exhibitor share) and shareholder information, 2026. https://www.relx.com/investors/shareholder-information
19. GL events, "Investor Relations" and 2025 press releases, 2025–2026. https://www.gl-events.com/en/investors-relation
20. U.S. Securities and Exchange Commission, "Apollo Funds to Acquire Emerald and Questex," 2026. https://www.sec.gov/Archives/edgar/data/1579214/000119312526215652/d22741dex991.htm
21. Blackstone, "Blackstone Acquires Clarion," 2017. https://www.blackstone.com/news/press/blackstone-acquires-clarion/
22. Cvent, "Blackstone Completes Acquisition of Cvent," 2023. https://www.cvent.com/en/press-release/blackstone-completes-acquisition-cvent
23. GES, "GES Completes Sale to Truelink Capital," 2024. https://insights.ges.com/news/ges-completes-sale-to-truelink-capital
24. TA Associates, "Introducing Momentive Software," 2024. https://www.ta.com/news/introducing-momentive-software-provider-of-cloud-based-software-that-powers-mission-driven-associations-and-nonprofit-organizations/
25. Momentive Software, "Momentive Software Accelerates Mission-Driven Innovation with Strategic Acquisition of Personify," 2026. https://momentivesoftware.com/press-releases/personify-acquisition/
26. Kellen Company / SmithBucklin, "What is an association management company (AMC)?," accessed 2026. https://kellencompany.com/blog/what-is-an-amc/