Employment Services (United States) — NAICS 5613

A Histometrics rollup primer for public-market and private investors. NAICS = North American Industry Classification System, the U.S. government's business-activity taxonomy. This page covers the four-digit industry group 5613 by synthesizing its three child industries and stating the group's own federal ground-truth figures.

1. Overview

NAICS 5613 Employment Services is the part of the economy that stands between employers and workers. It sits inside the sector Administrative and Support and Waste Management and Remediation Services (code 56), under Administrative and Support Services (561), and it bundles together three very different ways of being a labor-market intermediary [1][2].

The cleanest way to hold the group in your head is one question: when the worker gets paid, whose employee is he or she? That single distinction sorts the entire group and drives everything an investor cares about — margins, capital intensity, cyclicality, ownership, and how you buy in:

• You introduce the worker and step away — recruiters and headhunters who fill a client's opening, where the placed person becomes the client's employee. This is 56131 Employment Placement Agencies and Executive Search Services — a capital-light, near-100%-gross-margin fee business [3].
• You employ the worker and rent them out — staffing agencies that carry temps on their own payroll and bill clients for hours worked. This is 56132 Temporary Help Services — a high-volume, low-margin spread business [4].
• You co-employ the worker and run the paperwork — Professional Employer Organizations (PEOs) that become the legal employer-of-record for a client's existing staff, handling payroll, benefits, and human-resources (HR) compliance while the client still directs the work. This is 56133 Professional Employer Organizations — part outsourcing firm, part insurance intermediary [5].

All three are cyclical bets on employment, all three are fragmented, and all three are being actively rolled up by private equity (PE). But they could hardly be more different in size, economics, and how you own them — and that contrast is this page's whole reason to exist. The group is genuinely large on paper (~$558 billion of receipts, ~7.8 million counted "employees"), but as Section 3 explains, those two headline numbers mean very different things across the three children and must be read with care.

2. What's inside — the three children and how they differ

The value of looking at 5613 instead of one child is the contrast across the three. The table below sets it out; all federal figures are our ground-truth for each code (receipts from the 2022 Economic Census, "EC"; employment/payroll from 2023 County Business Patterns, "CBP") — see Section 3 for the caveats [6][7][8][9].

Acronyms in the table: CR4 = combined revenue share of the four largest firms; HHI = Herfindahl-Hirschman Index, a standard concentration gauge that runs toward 10,000 for a monopoly and under 1,500 for an "unconcentrated" market under U.S. antitrust guidelines; W-2 = the U.S. tax form for an employee; PE = private equity.

The one contrast that reorganizes everything: the "employment relationship" row. In 56131 the intermediary never touches the worker's paycheck — it earns a fee for an introduction and the ~368,000 counted employees are the recruiters themselves. In 56132 and 56133 the intermediary is the legal employer, so the millions of counted "employees" are the placed and co-employed workers — people who physically work at a factory, hospital, warehouse, or small business but are booked here, at their employer of record. That is why 56132 and 56133 together hold ~95% of the group's counted headcount and ~96% of its payroll while running only ~76% of its establishments: each of their sites administers a large pool of off-site workers (a PEO establishment fronts roughly 870 co-employed workers) [7][8][9].

Where the children shade into confusion. The three are routinely blended together as "staffing," but the boundaries are sharp and matter for underwriting. Placement/search (56131) hands the worker to the client's payroll; temp help (56132) keeps the worker on its own; PEOs (56133) co-employ a client's existing staff and never source the worker at all. Adjacent codes that are not in this group but often mistaken for it include online job boards and professional networks (Indeed, LinkedIn, ZipRecruiter — classified as internet publishing/advertising) and HR- or payroll-only providers that never take employer-of-record status [3][4][5].

3. How big it is — the group's rollup figures

Our ground-truth federal figures for the group, NAICS 5613 (U.S.):

A textbook-clean roll-up — with one honest wrinkle. The children sum to the group almost exactly: establishments add up precisely (13,576 + 38,254 + 4,343 = 56,173), employment adds up precisely (368,130 + 3,645,678 + 3,777,023 = 7,790,831), payroll ties to the dollar-rounding (~$471.8B), and receipts tie to ~$557.87B [6][7][8][9]. The only gap is firms: the children sum to 31,534 versus the group's 31,331, because ~203 companies operate under more than one of these codes and are counted once at the group level but in each child they touch. That tight additivity is a good sign the federal data are internally consistent.

Read the size numbers carefully — they mix gross and net. The group's ~$558 billion of receipts is not an apples-to-apples total, because the three children book revenue on different bases:

• 56132 (temp help) receipts are gross — an agency bills the client for hours worked, and most of that bill is passed straight through to the temp's wages. So its ~$326B (58% of the group) is inflated by wage pass-through and is a low-value-add-per-dollar figure by design [4].
• 56133 (PEO) receipts are largely net — many PEOs report only their service and insurance fees, while the far larger pass-through wages of co-employed workers flow through the payroll line, not receipts. That is why PEO payroll ($273B) exceeds PEO receipts ($198B), the reverse of a normal industry [5].
• 56131 (placement/search) receipts are pure fees — near-100% of them are gross profit [3].

The practical consequence: you cannot rank the children by economic weight on the receipts row alone, and you cannot compute a meaningful "revenue per employee" across the group, because in 56131 the denominator is the intermediary's own staff while in 56132/56133 it is the placed or co-employed workforce. Payroll is not profit, and the federal data report no operating margin, average fee, spread, or total addressable market for the group.

Undercount caveat — which mostly runs the other way here. For most industries, federal tabulations undercount the smallest operators, because CBP counts only establishments with paid employees and excludes the self-employed, firms without an employer identification number, and most government workers [6]. Two of this group's three children are the opposite case: temp help and PEOs are inherently employer-based, run formal W-2 payrolls, and are captured well (PEO's ~3.78 million counted workers lines up with the trade body's independent ~4.5 million worksite-employee estimate [10]). The classic undercount survives only in the smallest child — 56131's long tail of independent, one-person recruiters operating as sole proprietors, who never appear in the establishment count. So the group's overall footprint is captured solidly, with the invisible-operator problem confined to placement's solo-recruiter tail. Our ground-truth file carries no nonemployer total, so we state none. Two further quirks worth flagging: the ~7.8 million headcount is a point-in-time snapshot of an industry that churns unusually fast (the American Staffing Association estimates ~2.2 million temps on assignment in an average 2024 week but ~11.2 million different people cycling through staffing jobs across the full year [11]); and temp/PEO employment is pulled out of the factories, hospitals, and warehouses where the work is physically done and booked here instead [7].

Concentration — the group looks less concentrated than its most concentrated child. The group HHI of 105.4 and CR4 of 17.0% sit below the PEO child's own figures (HHI 470, CR4 35%) and near the temp child's (HHI 138). That is an aggregation effect, not a contradiction: merging three industries into one ~$558B denominator shrinks every firm's share, so even the concentrated PEO leaders hold small slices of the combined market [6][7][8][9]. The plain-English read is the same at every level — no one dominates. (Because this is a receipts-based Census measure, treat the HHI as a fragmentation signal, not a Department of Justice merger-screening score.)

4. The investable universe — where value concentrates across the children

There is no pure-play, publicly traded way to own NAICS 5613 as a whole; every listed name is a diversified company in which one or two of these children are a segment. But the three children differ sharply in how much of their value is even reachable in public markets — and the group's odd feature is that its smallest child by revenue offers the least public access, while a mid-sized child offers the most.

• 56131 Placement & Executive Search — the least public. No listed pure-play exists. Placement shows up as a high-margin line inside diversified staffing firms (Robert Half, Kforce), and executive search survives publicly almost only through Korn Ferry, where search is about a third of a diversified talent-solutions business; the last large listed pure-play, Heidrick & Struggles, was taken private by Advent International/Corvex in December 2025 [12][13]. The marquee search franchises (Spencer Stuart, Russell Reynolds, Egon Zehnder) are partner-owned, and most of the child's value sits in founder boutiques and PE roll-ups [3].
• 56132 Temporary Help — the deepest public bench, but tilted private at the very top. A dozen U.S.-listed staffing names trade here (ManpowerGroup, Robert Half, Kelly, Kforce, AMN Healthcare, Cross Country Healthcare, TrueBlue, HireQuest, BGSF, GEE Group), plus European majors Randstad and Adecco with large U.S. operations — yet the single largest U.S. staffing firm, Allegis Group, is private, as are healthcare leader Aya Healthcare, IT leader Insight Global, and industrial staffer Employbridge [14].
• 56133 PEO — the cleanest pure-plays in the whole group. Two listed pure-play PEOs (TriNet, Insperity), a PEO-plus-staffing hybrid (Barrett Business Services), and two payroll/human-capital-management giants running large PEO segments (ADP, whose TotalSource is the biggest U.S. PEO by worksite employees, and Paychex) [15]. The private tail is PE roll-up platforms (Vensure, Engage, G&A) and venture-backed HR-technology firms (Justworks, Rippling, Gusto, Deel) [16].

(Tickers, revenues, and market caps move constantly; the names above are for orientation, not quotes. Underwrite every one of them on the net-fee / net service revenue attributable to these activities — not on consolidated revenue swollen by temp wage pass-through, PEO gross billings, or unrelated consulting. Company-level tables live in the three child primers.)

5. How the money works

The group's three children share a cyclical spine but earn their keep in three genuinely different ways — this is the section where the "employment relationship" distinction turns into economics.

• 56131 — the fee. The agency is paid a one-time fee that scales with the pay of the role filled: contingency placement (~15–25% of first-year salary, paid only if the hire happens) or retained executive search (~30–35% of first-year total compensation, billed in thirds whether or not a hire is made). Because the placed worker never joins the agency's payroll, the fee is almost pure gross profit — a fee/brokerage business, not a labor-reselling one. Compensation of the recruiters is the dominant cost, giving strong incremental margins on the way up and painful operating deleverage on the way down. Revenue is largely one-and-done, with thin recurring backlog [3].
• 56132 — the spread. The agency pays a pay rate to the temp and charges a higher bill rate to the client; the difference funds employment costs and profit. Markup runs ~30–75% of pay, gross margin averages ~25% (thinner on commodity industrial labor, richer on IT/healthcare/professional), and net margin is slim (~3–8%) after branches, recruiters, insurance, and bad debt. It is high-volume, low-margin, high-operating-leverage — and working-capital intensive, because agencies pay temps weekly but collect from clients on 30–60 day terms, so growth consumes cash and balance-sheet strength is a weapon [4].
• 56133 — the fee plus the float plus the insurance spread. A PEO invoices the client for the full cost of employment (wages, payroll taxes, benefits, workers' comp) plus a service fee (a percentage of payroll or a flat per-employee-per-month rate). It earns money four ways: the service fee (scale economics on a largely fixed platform), the benefits and workers'-comp spread (pooling thousands of workers to buy insurance at large-group rates and bearing part of the claims risk — the biggest earnings swing factor), float (interest on prefunded payroll/tax dollars), and ancillary services. Reported margins look thin on total revenue because the denominator includes pass-through payroll and insurance; on net service revenue the economics are far richer [5].

The through-line: all three are capital-light or capital-cyclical fee businesses whose top line badly overstates the money actually kept. In placement/search the fee ≈ the profit; in temp help most of revenue is a wage pass-through; in PEO most of revenue (and nearly all of payroll) is a wage-and-insurance pass-through. Judge every operator on the net dollars it retains, not the gross it moves.

6. What drives demand

The whole group is a leveraged bet on hiring and employment confidence, but each child reads the signal differently.

• The business cycle drives everything. Gross domestic product (GDP), corporate profit expectations, and hiring plans lift all three; uncertainty freezes discretionary labor spend first. The Bureau of Labor Statistics' Job Openings and Labor Turnover Survey (JOLTS) is the standard read; through 2025 the quits rate sat below its pre-pandemic norm, a "low-hire, low-fire, low-churn" market that starves activity even without a recession [17].
• 56132 leads the cycle. Temp employment is a classic leading indicator — the marginal unit of labor added first in a recovery and cut first in a slowdown. BLS reported temp-help employment fell ~159,000 in 2024 and ~624,000 from its March 2022 peak; the "penetration rate" (temps as a share of private employment) sat around 1.56–1.59% in 2025–2026, below ~2% cyclical peaks — a still-soft market [18].
• 56131 tracks churn and executive turnover. Voluntary job-switching feeds placement; record executive and board turnover (Challenger, Gray & Christmas counted 1,991 U.S. CEO exits in 2024, its most on record) feeds retained search somewhat independently of the broader hiring cycle [19].
• 56133 rides small-business formation and complexity. More small-business employees to co-employ, plus rising multi-state regulatory and benefits complexity, is a durable outsourcing tailwind — and penetration is still low (only ~17% of firms with 10–99 employees use a PEO), leaving structural runway less tied to the cycle than the other two [10].
• Skills scarcity and wage inflation lift all three: the harder talent is to find, the more employers outsource; and because fees, spreads, and service charges are pay-linked, rising wages mechanically lift revenue (though very steep wage growth can also delay hiring).

7. Regulation

There is no single federal license for "employment services"; instead each child carries its own regime, layered on a common base of employment law. As intermediaries in hiring and employment, all three touch federal anti-discrimination law (Title VII, the Age Discrimination in Employment Act, the Americans with Disabilities Act, enforced by the Equal Employment Opportunity Commission, "EEOC") and candidate-data rules under the Fair Credit Reporting Act (FCRA) [20][21].

• 56131 (placement/search): state-by-state licensing and fee caps for private employment agencies (a legacy of early-20th-century abuses), plus a fast-emerging overlay of AI-in-hiring rules targeting algorithmic bias (e.g., New York City Local Law 144's bias-audit and disclosure mandate) as firms adopt automated sourcing and screening [20].
• 56132 (temp help): the defining feature is co-employment liability — the agency employs the worker while the client directs the work, so both can carry employer obligations. Governing rules include the Fair Labor Standards Act (FLSA, minimum wage/overtime), joint safety duties under the Occupational Safety and Health Administration (OSHA), an unsettled "joint employer" standard at the National Labor Relations Board, and a rising wave of state "equal pay for temps" laws (New Jersey's Temporary Workers' Bill of Rights, Illinois's amended Day and Temporary Labor Services Act) that erode the cost advantage of temporary labor [22][23].
• 56133 (PEO): the most distinctive regime, because PEOs assume other companies' employment-tax and benefits liabilities — a voluntary federal IRS Certified PEO (CPEO) program with bonding, a state-by-state licensing patchwork, independent accreditation and financial assurance, and benefits law (the Employee Retirement Income Security Act, "ERISA," and the Affordable Care Act). The common thread is that regulation exists mainly to protect clients from a PEO's failure [24].

The shared regulatory direction of travel — expanding AI-hiring audits, narrowing joint-employer and equal-pay advantages, tightening data-privacy — raises compliance cost across the whole group and, at the margin, favors scaled operators who can absorb it.

8. Competitive dynamics and consolidation

Structure: fragmented everywhere, with one concentrated corner. Barriers to entry are low locally — a recruiter with client relationships and a payroll line can open a branch — so all three children have vast small-operator tails, reflected in the group's 17% top-four share and HHI of 105 [6]. The exception is PEO (HHI 470), where insurance-buying scale and platform economics reward size more than in the other two.

Consolidation is structural, not merely cyclical — and PE is the engine in all three children. The group is a textbook roll-up: recurring or repeatable client relationships, operating leverage from scale, technology synergies, and an aging cohort of founder-owners looking to exit.

• In placement/search, PE has moved upmarket (ZRG Partners is PE-backed; Advent/Corvex took Heidrick & Struggles private in December 2025), and staffing M&A multiples run roughly 4–7x EBITDA depending on specialty [12][25].
• In temp help, PE roll-ups in healthcare, IT, and industrial verticals plus public-company tuck-ins are constant, though integration risk means scale is not a guaranteed advantage [14].
• In PEO, the wave is fiercest: ~80% of 2025 PEO acquisitions targeted firms under $20 million in revenue, alongside strategic megadeals among the payroll/HCM giants (Paychex's ~$4.1 billion purchase of Paycor in 2025) — the strategic logic being that a bigger worksite-employee pool means better insurance buying power and lower per-employee platform cost [16].

The shared disruptive front: platforms and AI. Across the group the competitive threat is less another agency than technology that lets employers self-serve — job boards, vendor-management systems, direct-sourcing tools, and generative AI that automates sourcing, screening, and scheduling. The pressure lands hardest on high-volume, transactional work (commodity recruiting and light-industrial temp) and leaves judgment-heavy, confidential, or compliance-laden work (executive search, specialty healthcare staffing, PEO co-employment) comparatively defensible.

9. Risks

• Cyclicality above all. Every child is a high-beta bet on employment; with sticky people costs and thin recurring backlog, profits fall hard and fast in a downturn (56132 most violently, then 56131; 56133's recurring service fees cushion it somewhat).
• Confusing revenue with value. The group's ~$558B top line is mostly wage-and-insurance pass-through; several children can grow gross revenue while net economics stagnate. This is the single most common analytical trap here.
• Structural disintermediation. AI, self-service platforms, and in-house recruiting erode the middleman's fee for commoditized roles across placement and temp help [26].
• Margin fragility and working capital (56132) and insurance-cost volatility (56133). Spread compression when pay rises faster than bill rates, cash-hungry growth in temp help; unpredictable workers'-comp and health-claims costs in PEO — its largest earnings risk.
• Regulatory drift. Co-employment and joint-employer liability, equal-pay-for-temps laws, AI-hiring audits, and PEO tax/benefits obligations raise compliance cost and can narrow the cost advantages these firms sell.
• Key-person and roll-up execution risk. The assets ride the elevator down every night; star billers can defect with clients, and PE consolidation depends on integrating people-dependent shops without losing them.
• Thin, uneven public access. No pure-play for the group as a whole; placement/search is nearly un-investable publicly, while temp and PEO equities are cyclical, sometimes small-cap and illiquid.
• Measurement risk. Federal statistics mix gross and net receipts across the children, omit nonemployers and most solo recruiters, and report no margin or growth series — so they do not support a standalone market-growth claim for the group [6].

10. How to invest, and the outlook

The three children are three different investments wearing one label. Choosing among them is choosing your exposure to the labor market's structure:

• 56131 Placement & Executive Search — the smallest and highest-margin, most naturally owned privately (founder boutiques, prestige partnerships, PE roll-ups). Public access is proxy-only: Robert Half and Kforce for professional direct-hire economics, Korn Ferry for a diversified search-anchored name [3][12].
• 56132 Temporary Help — the largest by revenue and the deepest public bench of cyclical, capital-light, cash-returning value equities (ManpowerGroup, Kelly, AMN, Cross Country, TrueBlue, HireQuest; Randstad/Adecco for global exposure) — cheap-looking at the bottom of a hiring cycle, expensive-looking at the top. Or go private: buy, build, or franchise an agency, or lend against staffing receivables for a cash-flow route without the equity cyclicality [4][14].
• 56133 PEO — the most defensible growth profile and the cleanest public pure-plays in the group (TriNet, Insperity; the hybrid Barrett; lower-volatility ADP/Paychex), judged on net service revenue, worksite-employee growth, insurance-cost ratios, and retention — never on gross billings [5][15].

What to watch (forward-looking). The clearest near-term catalyst for the whole group is a return of labor-market churn — JOLTS quits and hires climbing back toward normal after a long freeze [17]; layered on that are the temp penetration rate (the cyclical gauge for 56132) [18], executive/CEO turnover (a search driver less tied to the cycle) [19], small-business hiring and PEO penetration (a structural grower for 56133) [10], wage inflation (which lifts all three fee bases mechanically), the pace of AI adoption (whether it hollows out transactional work faster than firms move upmarket) [26], and M&A tempo, as founder-owner succession and PE conviction keep feeding a consolidation wave across all three children [16][25].

The considered view. Long-run demand for human intermediation in scarce-skill, confidential, senior, and compliance-heavy labor is durable and more defensible than commodity résumé-forwarding or bodies-on-benches. Within 5613 that points the same direction as the "employment relationship" spine: the judgment- and compliance-intensive ends — executive/specialist search and PEO co-employment — look structurally sturdier, while the commodity/transactional ends — light-industrial temp and low-skill placement — face the sharpest technology squeeze. Either way, this group is investable mainly through cyclical public staffing/PEO names and private PE platforms, and company-specific underwriting on net economics matters far more than the industry label.

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Sources

1. U.S. Census Bureau, "2022 NAICS — Industry Group 5613 Employment Services (definition and structure: 56131, 56132, 56133)." https://www.census.gov/naics/?input=5613&year=2022&details=5613
2. U.S. Census Bureau, "2022 NAICS — Sector 56 / Subsector 561 Administrative and Support Services." https://www.census.gov/naics/?input=561&year=2022&details=561
3. Histometrics primer, NAICS 56131 — Employment Placement Agencies and Executive Search Services (full company roster, fee models, off-limits rule, and citation set).
4. Histometrics primer, NAICS 56132 / 561320 — Temporary Help Services (spread economics, penetration rate, company roster).
5. Histometrics primer, NAICS 56133 / 561330 — Professional Employer Organizations (co-employment, insurance-spread economics, company roster).
6. U.S. Census Bureau — Histometrics ground-truth dataset for NAICS 5613: 2022 Economic Census (receipts $557.867B; firms 31,331; CR4 17.0%, CR8 23.2%, CR20 34.1%, CR50 47.1%; HHI 105.4) and 2023 County Business Patterns (establishments 56,173; employees 7,790,831; annual payroll $471.771B; Q1 payroll $120.498B). CBP excludes nonemployers, businesses without an EIN, and most government employees. https://www.census.gov/programs-surveys/economic-census.html; https://www.census.gov/programs-surveys/cbp.html
7. U.S. Census Bureau, 2022 Economic Census & 2023 County Business Patterns, NAICS 56131 — receipts ~$33.97B; establishments 13,576; employees 368,130; annual payroll ~$21.90B; CR4 10.2%; HHI 43.5.
8. U.S. Census Bureau, 2022 Economic Census & 2023 County Business Patterns, NAICS 56132/561320 — receipts ~$326.0B; establishments 38,254; employees ~3.646M; annual payroll ~$177.3B; CR4 18.1%; HHI 137.7.
9. U.S. Census Bureau, 2022 Economic Census & 2023 County Business Patterns, NAICS 56133/561330 — receipts ~$197.9B; establishments 4,343; employees 3,777,023; annual payroll ~$272.6B; CR4 35.4%; HHI 470.3.
10. National Association of Professional Employer Organizations (NAPEO), "Industry Overview / Industry Statistics" (~4.5M worksite employees; ~17% penetration among firms with 10–99 employees). https://www.napeo.org/what-is-a-peo/about-the-peo-industry/industry-statistics
11. American Staffing Association, "Staffing Industry Statistics" (~2.2M weekly / ~11.2M annual staffing employees; occupational mix). https://americanstaffing.net/research/fact-sheets-analysis-staffing-industry-trends/staffing-industry-statistics/
12. U.S. SEC — Heidrick & Struggles Form 8-K (Advent International/Corvex take-private completed December 2025, $59.00/share, ~$1.3B); Korn Ferry Form 10-K (executive search ~a third of ~$2.8B diversified talent-solutions revenue). https://www.sec.gov/Archives/edgar/data/1066605/000119312525313582/d832427d8k.htm; https://www.sec.gov/Archives/edgar/data/56679/000005667926000021/kfy-20260430.htm
13. Recruitment fee structures: TopEchelon, "Recruitment Agency Fee Structures"; Cowen Partners, "Executive Search Firms & Fees." https://topechelon.com/blog/recruitment-agency-fee-structures/; https://cowenpartners.com/the-two-types-of-executive-search-firms-fees/
14. Staffing Industry Analysts, "Largest US/Global Staffing Firms" and "US Staffing Industry Forecast" (public staffing majors; Allegis, Aya, Insight Global, Employbridge private; total U.S. staffing market ~$184B in 2024, +3% projected 2025). https://www.staffingindustry.com/research/research-reports/americas
15. Public PEO and payroll/HCM issuers: TriNet (NYSE: TNET), Insperity (NYSE: NSP), Barrett Business Services (Nasdaq: BBSI), ADP (Nasdaq: ADP, TotalSource), Paychex (Nasdaq: PAYX) — Forms 10-K and quarterly results. https://www.sec.gov/cgi-bin/browse-edgar
16. NAPEO PEO Insider, "Inside the PEO M&A Market" (~80% of 2025 PEO deals under $20M revenue; Paychex–Paycor ~$4.1B, 2025); Staffing Industry Analysts, "M&A Trends: North America." https://peoinsider.org/articles/inside-the-peo-ma-market-key-insights-and-future-outlook/
17. U.S. Bureau of Labor Statistics, "Job Openings and Labor Turnover Survey (JOLTS)"; Indeed Hiring Lab (2025) — quits rate ~1.8–2.0%, below pre-pandemic norm. https://www.bls.gov/jlt/home.htm
18. U.S. Bureau of Labor Statistics, Monthly Labor Review (2025) and FRED series TEMPHELPS — temp-help employment −159,000 in 2024, −624,000 from March 2022 peak; penetration rate ~1.56–1.59% (2025–2026). https://www.bls.gov/opub/mlr/; https://fred.stlouisfed.org/series/TEMPHELPS
19. Challenger, Gray & Christmas / Forbes, "CEO Turnover Soars in 2024" — 1,991 U.S. CEO exits, a record since tracking began in 2002. https://www.forbes.com/sites/julianhayesii/2024/12/22/ceo-turnover-soars-in-2024/
20. U.S. EEOC, "Coverage of Employment Agencies" (Title VII/ADA/ADEA); NYC Department of Consumer and Worker Protection, "Automated Employment Decision Tools (Local Law 144)"; state private-employment-agency licensing. https://www.eeoc.gov/employers/coverage-employment-agencies; https://www.nyc.gov/site/dca/about/automated-employment-decision-tools.page
21. Consumer Financial Protection Bureau, "Circular 2024-06: Background Dossiers and Algorithmic Scores for Hiring" (FCRA obligations; candidate-data privacy). https://www.consumerfinance.gov/compliance/circulars/consumer-financial-protection-circular-2024-06-background-dossiers-and-algorithmic-scores-for-hiring-promotion-and-other-employment-decisions/
22. U.S. Department of Labor, "Wages and the FLSA"; Occupational Safety and Health Administration, "Protecting Temporary Workers" (staffing agency and host jointly responsible); Congressional Research Service, "NLRB Joint Employer Rule vacated March 2024." https://www.dol.gov/agencies/whd/flsa/; https://www.osha.gov/temporaryworkers
23. Ogletree Deakins, "New Jersey Temporary Workers' Bill of Rights" (2023); Jackson Lewis / Illinois DOL, "Illinois Day and Temporary Labor Services Act" (2023–2025). https://ogletree.com/insights-resources/blog-posts/new-jersey-temporary-worker-pay-transparency-law-takes-effect/; https://www.jacksonlewis.com/insights/illinois-amends-temp-worker-law-boosting-employer-obligations
24. U.S. Internal Revenue Service, "Certified Professional Employer Organization (CPEO)"; Employer Services Assurance Corporation (ESAC), "PEO Accreditation"; NAPEO, "State PEO Laws & Regulations." https://www.irs.gov/tax-professionals/certified-professional-employer-organization; https://www.esacorp.org/; https://www.napeo.org/peo-resources/resources-by-topic/regulatory-database/
25. Lyndon Advisory, "Staffing and Recruitment M&A"; Staffing Industry Analysts, "Merger & Acquisition Trends: North America" — EBITDA multiples ~4–7x; PE roll-ups. https://lyndonadvisory.com/guides/staffing-recruitment-ma
26. HR Dive, "Glassdoor and Indeed announce layoffs" (2025); DHRMap, "Job Boards Are Dying — AI Is Becoming the New Hiring Front Door" (2025) — CareerBuilder/Monster parent Chapter 11, June 2025. https://www.hrdive.com/news/layoffs-glassdoor-indeed-ai-headwinds/752876/

U.S. Small Business Administration size standards (2023): NAICS 561311/561312 $34M receipts, 561330 $41.5M receipts. Company-level tickers, financials, and full citation sets appear in the three child primers (56131, 56132/561320, 56133/561330).