Labor Unions and Similar Labor Organizations (NAICS 81393)

A Histometrics industry primer for public- and private-market investors.

Rollup note. This is a short overview of a NAICS industry (5-digit code 81393). It contains a single child industry — 813930, Labor Unions and Similar Labor Organizations — so this level is effectively identical to that child. Read this page for the shape and the headline federal figures; for the full treatment (structure of the union movement, the investable universe, how dues economics work, regulation, and how to invest), see the 813930 primer.

1. Overview

Labor unions are member-funded organizations that bargain collectively with employers over pay, benefits, and working conditions. They are not businesses in the ordinary sense: no shareholders, no distributed profit, organized as tax-exempt labor organizations under Internal Revenue Code (IRC) section 501(c)(5) [1]. The "owners" are the dues-paying members, who elect the officers.

Investors care not because there is a "union" to buy — there essentially is not — but because unions are a large, organized counterparty to a big slice of the U.S. economy: autos, airlines, freight, grocery, healthcare, education, entertainment, the building trades, and the public sector. Where they are strong they shape labor costs, strike risk, contract cycles, and pension obligations that flow straight into the income statements of investable employers [1]. The economics that matter here are membership and density, dues retention, organizing win rate, strike-fund liquidity, and benefit-fund solvency — not same-store sales or capacity utilization.

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

The North American Industry Classification System (NAICS) organizes the economy in a tree: sectors (2-digit) split into subsectors (3), industry groups (4), industries (5), and national industries (6). NAICS 81393 sits at the 5-digit "industry" rung, one step above the leaf.

At this rung, 81393 has exactly one child, the 6-digit national industry 813930, which carries the same name. There is no second sibling to blend in, so the rollup and its child describe the same set of establishments — local trade unions, national and international unions, labor federations, and employee/collective-bargaining associations [2]. Everything true of 813930 is true of 81393; the code exists only to give the industry a place in the hierarchy before it terminates in a single leaf.

For scope and boundaries — how 81393 differs from business associations (81391), professional organizations (81392), and political organizations (81394), and why apprenticeship training is classified under education instead — see Section 2 of the 813930 primer.

3. Size of this level (rollup figures + undercount caveat)

Because 81393 has one child, its rollup equals the child's numbers exactly. The U.S. Census Bureau's County Business Patterns (CBP) program counts unions only as employers — the paid staff they put on payroll, not the members they represent. For NAICS 81393 in 2023 [3]:

These are employer-establishment statistics, not industry revenue. Our ground-truth stats file for this level carries no dues total, membership count, assets, or investment income, so we do not state those figures here [3]. Two undercount gaps are structural and central to reading the sector:

• The ~137,000 payroll employees are the organizers, negotiators, and administrative staff unions hire — not the roughly 14.7 million members (10.0% of wage-and-salary workers in 2025) whose dues fund the organizations and whose pay and benefits the unions bargain over [4].

• CBP excludes most establishments reporting government employees, plus nonemployer businesses and those without an Employer Identification Number [3]. Because the public sector is the most heavily unionized part of the movement (roughly one in three government workers, versus about one in seventeen private-sector workers), a large share of union activity sits outside CBP coverage by construction [4].

Treat the establishment count as a benchmark for paid union-office employment, while the economically meaningful footprint — dues revenue and tens of billions in assets (one analysis of Department of Labor filings put aggregate union net assets near $32.7 billion in 2022 [5]) — sits mostly outside these figures. Full size discussion is in Section 3 of the 813930 primer.

4. Investable universe (where value concentrates across the children)

With a single child, there is nowhere for value to "concentrate across" — the entire investable story is 813930's, and it is a story of proxy exposure rather than a listed pure-play. There is no listed security whose primary business is a labor union. Public exposure comes in three buckets: one union-rooted bank (Amalgamated Financial, ticker AMAL), diversified benefits/payroll/insurance firms whose union and Taft-Hartley work is a small slice of a much larger business (Aon, Arthur J. Gallagher, Willis Towers Watson, Automatic Data Processing, Paychex), and the unionized employers whose labor cost and strike risk are the realistic public angle. Private-market exposure is more direct — labor-owned insurers and managers such as ULLICO, benefit-fund third-party administrators, actuarial consultants, and the Taft-Hartley trusts themselves. The full universe, with tickers and the "size the actual union slice" caveat, is in Section 4 of the 813930 primer.

5. How the money works

The economics run closer to a subscription membership business than a manufacturer. The engine is dues, typically 1–2% of a member's gross earnings, so revenue ≈ members × dues rate — meaning it scales with density and with member pay [6]. Money also flows up the federated pyramid as a per-capita tax paid by locals to nationals and by nationals to federations. Costs are staff and representation, organizing, strike benefits, training, and political spending. "Profit" shows up as growth in net assets, which capitalizes the strike fund — the war chest behind any credible strike threat. Financial health is public: covered unions file an annual Form LM-2 with the Department of Labor's Office of Labor-Management Standards (OLMS) [7]. A separate Taft-Hartley multiemployer benefit-fund layer — jointly trusteed by union and employer trustees under the Employee Retirement Income Security Act (ERISA) — sits outside union operating cash flow and is where recurring per-participant service fees are earned [7]. Detail is in Section 5 of the 813930 primer.

6. Demand drivers

"Demand" here means demand for union representation — the pipeline of members and bargaining units. The main drivers: employment in union-heavy sectors (density concentrates in utilities, transportation and warehousing, and educational services); the public sector, the single biggest structural driver given its far higher density; worker sentiment and cost of living (union approval near a six-decade high at 68% of adults, though sharply split by politics); organizing wins at new employers (Starbucks, Amazon, Trader Joe's, REI); and headline bargaining wins such as the United Auto Workers' 2023 Detroit-Three contracts and the 2023 Hollywood writers' and actors' strikes [4][8]. Workplace disruption is a signal too: the Bureau of Labor Statistics counted 30 major work stoppages idling 306,800 workers in 2025 [9]. See Section 6 of the 813930 primer.

7. Regulation

Labor law is this industry's operating environment, and it splits by sector. The National Labor Relations Act (NLRA, 1935) charters private-sector bargaining and created the National Labor Relations Board (NLRB); the Labor Management Relations Act (Taft-Hartley, 1947) rebalanced toward employers and authorized state "right-to-work" laws (26 states as of 2024); the Labor-Management Reporting and Disclosure Act (LMRDA, 1959) governs member rights and the LM-2 financial filings [10][11][12]. Rail and airlines fall under a separate Railway Labor Act regime; public-sector bargaining is governed by state law, not the NLRA. The pivotal recent shift is Janus v. AFSCME (2018), which barred compulsory "agency fees" for government workers and effectively imposed right-to-work across the entire public sector — a direct hit to the dues base of the very unions that now dominate the movement [13]. Benefit plans run under ERISA, backstopped by the Pension Benefit Guaranty Corporation. Full regulatory map is in Section 7 of the 813930 primer.

8. Consolidation

Long-run membership decline has pushed unions to merge to preserve scale, staff, and strike funds; today's mega-unions are products of decades of combinations, and concentration is high — a handful of unions hold most members and most assets [5]. Unions also compete for members and jurisdiction ("raiding"), constrained by federation rules; the 2005 split that created a rival coalition fractured the movement, and the Service Employees International Union's 2025 return to the AFL-CIO marks a partial reconsolidation. Separately, private buyers are rolling up the service layer — Taft-Hartley third-party administrators and benefit consultants. Detail in Section 8 of the 813930 primer.

9. Risks

The defining risk is secular density decline — private-sector membership at 5.9% is the lowest on record — compounded by legal and political headwinds (a less union-friendly NLRB, right-to-work expansion, the ongoing drag from Janus) [4][13]. Other standing risks: strike and operating disruption, automation and artificial intelligence shrinking unionized job classes, governance and fraud exposure in organizations that manage member money, and benefit-fund underfunding in Taft-Hartley multiemployer plans (stabilized for now by the American Rescue Plan Act's Special Financial Assistance program). For the investable names, the recurring hazard is proxy mismatch — union work is often a small, undisclosed slice of a diversified firm's revenue. See Section 9 of the 813930 primer.

10. How to invest & outlook

There is no pure-play, so the routes are: the closest direct security, Amalgamated Financial (AMAL), underwritten as a bank with a labor-aligned client base; diversified proxies in benefits, retirement, and payroll (Aon, Arthur J. Gallagher, Willis Towers Watson, Automatic Data Processing, Paychex), sizing the small union slice; and indirect positioning around unionized employers, treating labor as a cost and event variable with tradable contract-expiration and strike catalysts. Private routes run through Taft-Hartley pension and benefit funds, ULLICO, the AFL-CIO Housing Investment Trust, and private buyers of benefit-fund administrators and consultants.

Outlook. The tension is stark: public approval near a 60-year high, a doubling of NLRB election petitions since 2021, and high-profile wins on one side; record-low private density, a hostile federal regulatory turn, and the continuing bite of Janus on the other. The likeliest path is a two-speed sector — energetic, headline-grabbing organizing at the margin, layered on a slowly shrinking aggregate footprint, with public-sector unions and established benefit funds providing the stability and the clearest investable cash flows likely to stay in adjacent service providers rather than in unions themselves [4][13][14]. Full how-to-invest guidance and watch items are in Section 10 of the 813930 primer.

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Because NAICS 81393 contains only the single national industry 813930, this page is a summary; the 813930 primer is the authoritative source for every section above.

Sources

Drawn from the child primer (NAICS 813930); numbering here is independent of that document.

1. Internal Revenue Service, "Labor and Agricultural Organizations" (IRC 501(c)(5)), 2026. https://www.irs.gov/charities-non-profits/other-non-profits/labor-and-agricultural-organizations
2. U.S. Census Bureau / NAICS, "813930 Labor Unions and Similar Labor Organizations" definition and related 8139 codes, 2022. https://www.census.gov/naics/?details=813930&input=813930&year=2022
3. U.S. Census Bureau, County Business Patterns 2023, NAICS 81393/813930 (establishments, employment, payroll), per the supplied ground-truth file; coverage exclusions per CBP "About and Methodology," 2026. https://www.census.gov/programs-surveys/cbp.html · https://www.census.gov/programs-surveys/cbp/technical-documentation/methodology.html
4. U.S. Bureau of Labor Statistics, "Union Members Summary — 2025," 2026; Gallup, "Labor Union Approval Relatively Steady at 68%," 2025. https://www.bls.gov/news.release/union2.nr0.htm · https://news.gallup.com/poll/694472/labor-union-approval-relatively-steady.aspx
5. Radish Research, "New 2023 Data on Union Membership and Finances" (analysis of DOL OLMS LM-2 filings), 2024. https://radishresearch.substack.com/p/new-2023-data-on-union-membership
6. Emergency Workplace Organizing Committee, "Union dues explained," 2024. https://workerorganizing.org/union-dues-explained-16597/
7. U.S. DOL OLMS, "Final Rule Modernizing Labor Organization Annual Reports" (Form LM-2), 2026; U.S. Pension Benefit Guaranty Corporation, ERISA multiemployer program. https://www.dol.gov/agencies/olms/notice-lm-2-longform-rule · https://www.pbgc.gov/american-rescue-plan-act-of-2021
8. The Washington Post, "UAW workers ratify new contracts with Big Three automakers," 2023; Wikipedia, "2023 SAG-AFTRA strike," 2023. https://www.washingtonpost.com/business/2023/11/20/uaw-contract-ford-general-motors-stellantis/ · https://en.wikipedia.org/wiki/2023_SAG-AFTRA_strike
9. U.S. Bureau of Labor Statistics, "30 Major Work Stoppages Began in 2025 and Idled 306,800 Workers," 2026. https://www.bls.gov/opub/ted/2026/30-major-work-stoppages-began-in-2025-and-idled-306800-workers.htm
10. U.S. National Archives, "National Labor Relations Act (1935)." https://www.archives.gov/milestone-documents/national-labor-relations-act
11. U.S. National Labor Relations Board, "1947 Taft-Hartley Substantive Provisions" and "Union Dues" (right-to-work). https://www.nlrb.gov/about-nlrb/who-we-are/our-history/1947-taft-hartley-substantive-provisions · https://www.nlrb.gov/about-nlrb/rights-we-protect/the-law/employees/union-dues
12. U.S. Department of Labor, "Labor-Management Reporting and Disclosure Act" (LMRDA), 2023. https://www.dol.gov/agencies/olms/compliance-assistance/fact-sheet/lmrda
13. LegalClarity, "Janus v. AFSCME: A Supreme Court Breakdown," 2024; Manhattan Institute, "The Legal Aftermath of Janus v. AFSCME." https://legalclarity.org/what-is-janus-v-afscme-a-supreme-court-breakdown/
14. The National Law Review, "Not Your Grandparents' Unions: NLRB Sees Large Rise in Organizing Petitions," 2024. https://natlawreview.com/article/not-your-grandparents-unions-nlrb-sees-large-rise-organizing-petitions