Other Automotive Repair and Maintenance (U.S.) — NAICS 81119

A Histometrics rollup primer for a general investing audience — relevant to both public-market and private investors. It synthesizes the three child-industry primers (811191 oil change, 811192 car washes, 811198 all other) against our ingested federal ground truth for this five-digit industry. Federal figures are U.S. Census Bureau and U.S. Small Business Administration (SBA) data; company, trade-body, and market-research numbers are labeled as such.

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1. Overview

The North American Industry Classification System (NAICS) — the U.S. government's business-classification scheme — code 81119, "Other Automotive Repair and Maintenance," is the quick-service, non-mechanical corner of the car-care economy. It sits alongside the two other pieces of automotive repair: mechanical and electrical repair (NAICS 81111 — engines, brakes, diagnostics) and body/paint/glass work (NAICS 81112 — collision shops). What is left in 81119 is everything that keeps a car maintained, clean, and protected without opening the hood for a major repair: routine oil changes, car washing, and a residual bucket of protection and light-service work (rustproofing, tire repair, air-conditioning service, paint film, and ceramic coating).[3]

Three child industries make up the level, and they are strikingly different businesses that happen to share a customer:

• 811191 — Automotive Oil Change and Lubrication Shops (the "quick lube": Jiffy Lube, Valvoline, Take 5).
• 811192 — Car Washes (express tunnels, in-bay automatics, self-serve, detailing).
• 811198 — All Other Automotive Repair and Maintenance (rustproofing, tire repair, A/C repair, paint protection film, ceramic coating — the catch-all).

Why it matters to an investor: this is recurring, mostly non-discretionary, real-estate-anchored, deeply fragmented car care — exactly the profile that has drawn a decade of private-equity (PE) roll-up capital. The federal government counts about 34,260 establishments generating roughly $27.7 billion in annual receipts and employing 271,951 people across the level.[1][2] But the three children differ on almost every axis an investor cares about — size, growth direction, who owns them, how concentrated they are, and how (or whether) you can buy them on a stock exchange. That contrast is the point of this primer, so we lead with it.

The single most useful public-market fact: across this entire five-digit industry, there is today only one clean, U.S.-listed pure-play — Valvoline, in the oil-change child. The car-wash pure-play (Mister Car Wash) was taken private in 2026, and the residual child never had one. Most of this industry trades privately, and that is itself the story.

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

The distinctive value of a rollup is the contrast across the children. The table below compares them on the axes that drive an investment decision. (Federal data give us no growth rates or margins, so "direction of travel" is drawn from the company and trade evidence in the child primers, not from the ground-truth file — treat it as informed judgment.)

How to read the contrast. Three takeaways matter more than the rest:

1. Car washes are the surprise heavyweight. People hear "auto repair" and picture a mechanic, but by revenue and by headcount this five-digit industry is majority car-wash — over half of receipts and nearly two-thirds of the workers.[1][2] It is also the most capital-intensive and most financialized child (memberships, sale-leaseback real estate, PE leverage).

2. Public access runs opposite to size. The smallest-but-cleanest public exposure is in oil change (Valvoline), the largest child (car washes) has no listed pure-play at all after Mister Car Wash went private in 2026, and the residual child offers only a supplier proxy (XPEL). If you want to own this theme in a brokerage account, you are mostly buying the oil-change child or an indirect proxy.[8][11][13]

3. The same sponsors treat the whole level as one thesis. Leonard Green & Partners owns both a car wash (Mister) and a tire/service platform (Sun Auto); Mavis (BayPine/TSG) owns an oil-change brand (Express Oil) and tire/repair chains; Driven Brands has held oil change (Take 5), car wash (Take 5, since divested), and repair (Meineke) under one roof.[9][11][16][14] Private capital sees "recurring, real-estate-backed car care" as a single roll-up game and moves across all three children.

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

Histometrics uses U.S. federal statistics as ground truth. For NAICS 81119 as a whole, and for the three children beneath it:

Note the vintage mix: receipts, firm counts, and concentration are 2022 Economic Census; establishments, employment, and payroll are 2023 County Business Patterns (CBP). They are consistent in magnitude but not a single synchronized snapshot.

The children add up — a useful cross-check. The three children's establishments (9,085 + 19,807 + 5,368 = 34,260), workers (77,250 + 172,644 + 22,057 = 271,951), payroll (~$8.89B), and receipts (~$27.7B) each tie to the level total almost exactly, which is what we should expect from a clean hierarchical rollup. The one small divergence is firms: the children sum to ~25,611 but the level shows 25,559, because a company that operates in two children is counted once at the level. The tiny gap (~50 firms) tells you these are mostly specialist operators — a company runs oil-change shops or car washes, rarely both.[2]

Concentration falls as you zoom out. The level's HHI of 42.7 is lower than any of its children (car washes 57, all other 86, oil change 212). The Herfindahl-Hirschman Index (HHI) sums the squared market shares of all firms; the U.S. Department of Justice (DOJ) treats anything under 1,500 as "unconcentrated," so 42.7 is near-atomized — pooling three distinct sub-markets dilutes any one firm's share of the combined pool.[24] The top four firms in the entire level hold just 10.5% of revenue.[2] This is genuinely one of the most fragmented five-digit industries in the economy — which is precisely why it is a roll-up magnet (Section 8). National data, though, says nothing about competition in any single town, where two or three washes or lube shops within a few miles is common.

The undercount caveat — read before citing a market size. These are employer-business statistics: CBP and the Economic Census summary universe cover establishments with paid employees and an employer identification number. They therefore understate the industry two ways:

• Missing nonemployers. One-person and mobile operators — mobile detailers, mobile tire-repair and rustproofing vans, solo paint-film installers — have no payroll and never appear. This is severe in the residual child (811198), which is unusually nonemployer-heavy; broad third-party estimates that fold in nonemployers run several times the measured employer floor.[25] Our ground-truth file does not include a nonemployer count for this level, so we do not state one.
• Missing secondary activity. A business is classified by its primary line, so every oil change done by a car dealer's service department or a tire chain, and every wash bolted onto a gas station or convenience store, is booked under a different code (dealerships, tire retail, fuel retailing) — not here. The federal ~$27.7 billion is a clean but narrow measure of firms that specialize in these services; total national spending on this kind of car care across all venues is materially higher.

The federal file also gives us no margins, growth rates, same-store sales, wash/car volumes, or capacity data for the level. Where those appear below, they come from company filings and trade surveys and are labeled as such.[1][2]

A quick profile from the ratios. The level averages roughly $809K of receipts and ~7.9 workers per establishment, at about $32,700 of pay per worker — small, local, service businesses.[1][2] But the children diverge: car washes carry the most workers per dollar of revenue at the lowest pay (~$29,400/worker — low-skill, automated tunnels), while the residual child pays the most (~$49,400/worker — scarcer A/C and paint-film technicians) out of the smallest shops (~4 workers each).

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

Very little of this industry is listed, and the listed exposure is lopsided toward one child. The table separates public routes from the private/franchise owners. Tickers and financials are for reference only; prices, yields, and multiples move continuously and should be judged against normalized cash flow, leverage, unit growth, and same-store performance.

Publicly traded (all exposure runs through, or adjacent to, the children):

Major private / franchise owners (representative, not exhaustive — private ownership changes without public reporting):

Takeaway. If you want this theme in a public portfolio, you are effectively buying the oil-change child through Valvoline (cleanest) or Driven Brands (diversified), with XPEL as a niche bet on the protection sub-segment. The largest child by far — car washes — is now entirely private after Mister's 2026 take-private. Everything else of scale sits inside PE portfolios, which is the industry's defining ownership story.

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5. How the money works

Despite different equipment, all three children share one economic identity: traffic × average ticket × margin, repeated across a network of small, standardized real-estate boxes. But the levers differ enough that a buyer should never underwrite them the same way.

• Oil change (811191): throughput plus upsell. Busy shops service 50–100 cars a day at ~$100+ tickets, at roughly 10–15% net margins for franchised units.[18] The base oil change is a traffic driver; the money is in mix (conventional → synthetic) and attach (filters, wipers, flushes). Same-store sales (SSS) — sales from stores open at least a year — is the metric that matters, and the leaders lean on it hard.[7]
• Car washes (811192): the membership flywheel. The modern thesis is the unlimited monthly membership (~$20–40/month), which turns a weather-dependent cash business into subscription-like recurring revenue — roughly three-quarters of wash revenue at the former public leader.[13] A member's extra wash costs pennies (water, chemicals, power), so once fixed costs are covered, incremental member revenue is almost all margin — and many members pay and rarely come (the gym-membership dynamic). A tunnel costs ~$3–8M+ to build and can gross ~$1.5–4M at unit-level margins of ~35–50%.[19] Because tunnels are highly automated, labor is a small cost here — the opposite of full-service detailing.
• All other (811198): labor and materials markup. Owners earn on technician hours and materials markup, not fixed assets. The swing factor is attach on premium work — a basic protection job is modest, a full paint-film or ceramic-coating package runs into the thousands.[13] Franchisors (Ziebart) and suppliers (XPEL) earn capital-light royalty and film-margin streams instead of operating shops.

The real-estate layer runs through all three. A lube pad, a wash tunnel, and a service bay are each two assets — an operating business and well-located "dirt." Operators routinely sell the property and lease it back on a 15–20-year triple-net (NNN) lease — where the tenant pays taxes, insurance, and maintenance — freeing capital to build the next unit.[19] Net-lease real-estate investors and REITs love these pads for their long, bond-like leases. The catch, visible in the car-wash reset, is that sale-leaseback rent is a fixed cost that does not fall when traffic does.

What a private buyer should actually underwrite (common across children): normalized store-level cash flow after replacing owner labor with market wages, funding maintenance capital, honoring environmental obligations, and pricing lease renewals — not headline sales. Local density and customer retention matter more than a headline store count.

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6. What drives demand

The three children ride the same macro base and then split on one variable — the electric vehicle.

Shared tailwinds (reported conditions):

• A large, aging fleet. About 289 million light vehicles are on U.S. roads, and the average vehicle is a record 12.8 years old.[5] Older, out-of-warranty cars drift toward independent and quick-service shops and get kept, cleaned, and protected longer — a durable positive for all three children.
• The do-it-for-me (DIFM) shift. Vehicle complexity, apartment living, and messy disposal push motorists to pay a shop rather than change their own oil or wash in the driveway. Every do-it-yourself (DIY) convert is a new customer.
• Miles driven. More vehicle-miles traveled (VMT) — the Federal Highway Administration (FHWA) recorded ~3.29 trillion in 2024 — uses up oil faster, dirties cars, and wears tires.[6]
• Replacement economics. High new- and used-car prices keep older cars on the road and reward maintaining and protecting the asset.

Where the children diverge — the EV split:

• Oil change is most exposed. Battery-electric vehicles need no engine-oil changes — the clearest long-term structural threat in the level, though slow to bite given a 289-million-vehicle, 12.8-year-old fleet.[7]
• Car washes are neutral-to-positive. EVs wash fine; the only issue is a consumer myth that they cannot.[19]
• The residual child is mixed-to-positive. EVs need less mechanical service but still need tires, A/C, and — crucially — EV owners buy heavily into paint film and coatings, so EV growth shifts the mix more than it threatens the need.[13]

Child-specific swing factors: oil change faces longer synthetic-oil intervals (3,000 → 7,500–15,000 miles) that cut visits per car (partly offset by higher-priced synthetic tickets); car washes ride weather, road salt, and the subscription habit (and suffer under drought/water restrictions); the residual child is seasonal (rustproofing before winter, A/C in summer) and its premium end is discretionary — a full ceramic package is one of the first things a household skips in a downturn.

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7. Regulation

The level carries a lighter regulatory load than mechanical or collision repair — no emissions or safety-inspection liability, low certification barriers — but each child has one binding rule tied to what it handles.

• Oil change — used oil. Under the federal Resource Conservation and Recovery Act (RCRA), the Environmental Protection Agency (EPA) regulates used oil at 40 CFR Part 279: shops are "used-oil generators" that must store it in labeled, leak-free tanks, respond to spills, and control transport.[20] All 50 states layer on their own rules.
• Car washes — wash-water discharge. Under the Clean Water Act (CWA), discharging wash water (oil, grease, detergents, sediment) to waters of the United States generally requires a National Pollutant Discharge Elimination System (NPDES) permit from the EPA; runoff to storm drains triggers stormwater rules, and recycling systems are increasingly required.[21] Because the business runs on recurring billing, the Federal Trade Commission's (FTC) auto-renewal / negative-option rules also bite.
• Residual child — refrigerant. Technicians who service a motor-vehicle air-conditioning (MVAC) system for pay must be certified under Section 609 of the Clean Air Act (CAA), using approved refrigerant-handling equipment.[22] Scrap-tire disposal, window-tint visible-light limits, and coating/solvent (VOC/PFAS) rules add state-level compliance.
• Shared: franchise law. Because all three children are heavily franchised, the FTC Franchise Rule governs the Franchise Disclosure Document (FDD) — 23 required items delivered at least 14 days before a franchisee signs or pays.[23]

Net: environmental compliance (used oil, wash-water, refrigerant) is the day-to-day regulatory reality; franchise and local rules (zoning, stormwater, licensing) do the rest. Regulation is a cost of doing business, not a barrier that concentrates the industry.

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8. Consolidation

The federal data paint the level as near-atomized (HHI 42.7; top four firms just 10.5% of revenue), and that fragmentation is exactly what drives its defining trend: private-equity roll-up.[2] The combination investors love — recurring, largely non-discretionary demand; real-estate-backed units; a franchisable model; and thousands of independent shops to acquire — has made all three children magnets for PE capital.

• The same sponsors span the children. Leonard Green holds Mister Car Wash and Sun Auto; Mavis (BayPine/TSG) holds Express Oil and NTB/Midas/Big-O tire; Driven Brands has held oil change, car wash, and repair brands together. Capital treats "recurring car care" as one thesis and rolls across the level.[9][11][14][16]
• But the children are at different points in the cycle. Oil change is in steady accumulation — top chains growing units and buying independents off a fragmented base. The residual child sees franchise + supplier-led consolidation (Ziebart, XPEL certifying installers) plus tire roll-ups (Mavis's pending ~$700M Pep Boys deal), but the independent tail is enormous and self-replenishing.[15] Car washes have already run through a boom and reset: cheap debt and sale-leasebacks funded a 2015–2023 express-tunnel building spree, then overbuilding and over-leverage caught up — ZIPS filed Chapter 11 in 2025 carrying ~$654M of debt, Driven Brands sold out of car washes entirely to cut debt, and Mister was taken private.[12][17]
• The lesson across all three: consolidation is not automatic pricing power. Competition stays local, national concentration badly understates a crowded trade area, and roll-ups destroy value through overpaying, excess leverage, weak integration, and store cannibalization. Store count alone is not a moat; site quality, membership/retention, and balance-sheet discipline are.

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9. Risks

• EV transition (differentiated by child). Structural and permanent in direction for oil change (no oil to change); closer to neutral for car washes and mixed-to-positive for the residual child. Watch the fleet's powertrain mix over years, not quarters.[7]
• Over-leverage and fixed rent (mainly car washes). Sale-leaseback rent does not fall when traffic does — the mechanism behind the ZIPS bankruptcy — and higher interest rates raise both financing and refinancing costs and can lift cap rates, lowering the value of the real estate many deals lean on.[17]
• Interval lengthening (oil change). Longer synthetic-oil intervals cut visits per car, only partly offset by higher tickets.
• Discretionary cyclicality (residual child, and one-time washes). Appearance, coating, and premium work is postponable; revenue softens fast in a downturn.
• Fragmentation and local saturation. Low entry barriers keep commodity margins thin; overbuilt metros cannibalize each other regardless of low national concentration.
• Labor. Low-wage, high-turnover work (car-wash turnover often tops 100% a year) and scarce skilled technicians (A/C, paint film) both pressure throughput and cost.
• Reputational and regulatory. Upsell/"scare-tactic" reputations invite consumer-protection scrutiny; mishandled used oil, wash-water, or refrigerant creates fines and cleanup liability; membership auto-renewal draws FTC/state attention.
• Roll-up execution. Sponsor platforms can accumulate leverage, integration problems, and goodwill impairments; franchisee distress can cut royalties and damage the brand.
• Data comparability. Employer-only federal statistics understate small and nonemployer activity (severe in the residual child), and public-company results bundle adjacent NAICS work — both the size and the public "proxies" must be read with care.

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10. How to invest, and the outlook

Public-market routes (concentrated in one child):

• Valvoline (NYSE: VVV) — the single cleanest way to own the level: a listed, pure-play quick-lube retailer with ~two decades of same-store-sales growth and ongoing unit growth.[7]
• Driven Brands (Nasdaq: DRVN) — Take 5 oil change plus Meineke/1-800-Radiator repair, bundled with other car-care brands; diversified, and now out of car washes.[9]
• XPEL (Nasdaq: XPEL) — the closest bet on the residual child's appearance-protection theme, but a volatile small-cap.[13]
• Monro (MNRO), Icahn (IEP), and suppliers/landlords — diluted, indirect exposure through tire-and-service chains, a complex holding company, or equipment/chemical makers and net-lease REITs that own the pads.[10][15]
• No public car-wash pure-play exists after Mister's 2026 take-private — a notable structural fact given car washes are the largest child.[11]

Private-market routes (where most of this industry actually trades):

• Own and operate — build or buy a quick-lube shop, a wash tunnel, or an A/C/tire-repair/protection shop; expect franchise or greenfield economics that vary widely by child (a 3-bay lube shop ~$600K–$1.2M; an express tunnel ~$3–8M+).[18][19]
• Franchise — Take 5, Jiffy Lube, or a Valvoline franchise (oil change); Tommy's Express (car wash); Ziebart or Tint World (residual). Obtain and read the FDD, and talk to existing franchisees first.[23]
• Own the real estate — a triple-net pad leased to a credit operator is a bond-like income asset across all three children, with tenant health and re-tenanting the key risks (as ZIPS showed).[17]
• Back a consolidator — equity or private credit into the PE platforms rolling up the sector; underwrite unit-level performance and leverage, not the growth-at-any-price story.

Diligence common to all three: verify tax returns against point-of-sale records; normalize owner compensation; inspect leases (especially related-party or sale-leaseback rent), environmental compliance, and equipment age; and count competing/planned sites within the drive time. For car washes specifically, add active-member count, churn, and remaining capacity; for the residual child, add attach rate on premium work and technician retention.

Outlook (forward-looking). The macro backdrop supports the whole level: a record-old, still-growing vehicle fleet, the ongoing DIFM shift, and high car prices that reward keeping, cleaning, and protecting the vehicle.[5][6] But the children point in different directions. Oil change looks steady and cash-generative, consolidating on top of years of same-store growth, with EV adoption the key long-horizon variable to monitor. Car washes — the biggest child — are past the boom and into a more disciplined, unit-economics-driven phase, with no public pure-play for now. The residual child offers steady, unspectacular growth with a fast-growing premium (film/coating) niche and the least EV risk, but the deepest fragmentation and the most discretionary spend. The reasonable base case for the level is a fragmented, recurring, slowly consolidating car-care economy where the best returns accrue to operators on excellent sites, with disciplined labor and leverage, who lean into the parts of each child that technology and demographics are adding to — protection, memberships, synthetic mix, fleet work — rather than the commodity service the same forces are slowly eroding.

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Sources

1. U.S. Census Bureau, County Business Patterns (CBP), 2023 — NAICS 81119 and children 811191 / 811192 / 811198 (establishments, employment, annual and Q1 payroll). Histometrics-ingested federal data. https://www.census.gov/programs-surveys/cbp.html
2. U.S. Census Bureau, 2022 Economic Census — Concentration of Largest Firms (EC2200SIZECONCEN), NAICS 81119 and children (receipts, firm counts, CR4/CR8/CR20/CR50, HHI). Histometrics-ingested federal data. https://data.census.gov/table/ECNSIZE2022.EC2200SIZECONCEN
3. U.S. Census Bureau, "NAICS 81119 — Other Automotive Repair and Maintenance (2022 definition)" and child definitions 811191 / 811192 / 811198. https://www.census.gov/naics/?details=81119&year=2022
4. U.S. Small Business Administration, "Table of Size Standards" (811191 = $11M; 811192 = $9M; 811198 = $10M receipts), 2023. https://www.sba.gov/document/support-table-size-standards
5. S&P Global Mobility, "U.S. Vehicle Age Rises Again to 12.8 Years in 2025" (~289M light vehicles), 2025. https://press.spglobal.com/2025-05-21-U-S-Vehicle-Age-Rises-Again-to-12-8-Years-in-2025-According-to-S-P-Global-Mobility
6. U.S. Federal Highway Administration, "Annual Vehicle Distance Traveled — 2024 (Table VM-1)" (~3.29 trillion VMT). https://www.fhwa.dot.gov/policyinformation/statistics/2024/vm1.cfm
7. Valvoline Inc., "Fourth Quarter and Fiscal Year 2025 Results" (net revenue, same-store sales, store counts). https://investors.valvoline.com/
8. Valvoline Inc., Form 10-K for fiscal year ended September 30, 2025 (~2,180 stores; franchisee share; competitors). https://www.sec.gov/Archives/edgar/data/1674910/000167491025000135/vvv-20250930.htm
9. Driven Brands Holdings Inc., Form 10-K FY2025 (4,200+ locations; Take 5 oil change; Meineke; 1-800-Radiator & A/C; U.S. car-wash divestiture). https://www.sec.gov/Archives/edgar/data/1804745/000180474526000048/drvn-20251227.htm
10. Monro, Inc., Form 10-K (tire-and-service stores; vehicles serviced). https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000876427&type=10-K
11. Mister Car Wash, Inc. / GlobeNewswire, "Mister Car Wash to Be Taken Private by Leonard Green & Partners for $7.00 Per Share" (~$3.1B; ~550 locations; ~2.3M members), 2026; SEC Form 8-K completion. https://www.globenewswire.com/news-release/2026/02/18/3240042/0/en/Mister-Car-Wash-to-Be-Taken-Private-by-Leonard-Green-Partners-for-7-00-Per-Share.html
12. Whistle Express Car Wash (Oaktree-backed), "Whistle Express to Acquire Take 5 Car Wash" (Driven U.S. car-wash divestiture, $385M), 2025. https://whistleexpresscarwash.com/news/
13. XPEL, Inc., "Q4 and Full-Year 2024 Results" (revenue $420.4M; gross margin 42.2%; installer network; PPF/ceramic exposure). https://www.businesswire.com/news/home/20250226143725/en/
14. Jiffy Lube, "Monomoy Capital Partners Completes Acquisition of Jiffy Lube from Shell" (~$1.3B; 2,000+ centers; ~100% franchised), 2026. https://www.jiffylube.com/news-and-press/monomoy-capital-partners-completes-jiffy-lube-acquisition
15. Mavis, "Mavis to Acquire Pep Boys from Icahn Enterprises" (~$700M, pending); Business Wire, "Mavis Completes Acquisition of Midas" (>3,500 locations), 2025–2026. https://www.mavis.com/news/mavis-pep-boys/
16. BayPine / TSG Consumer Partners, "Investor Group to Acquire Mavis Tire Express Services" (Express Oil Change & Tire Engineers platform), 2021. https://www.businesswire.com/news/home/20210305005229/en/
17. Focus Bankers, "Washing Away Debt: ZIPS Car Wash and the Cost of Private Equity Ambition" (Chapter 11, Feb 2025; ~$654M debt; ~$279M restructured), 2025. https://focusbankers.com/washing-away-debt-zips-car-wash-and-the-cost-of-private-equity-ambition/
18. National Oil and Lube News, "That's the Ticket" (operator survey: average ticket, car count, ~10–15% net margins), 2025. https://www.noln.net/running-a-shop/financeoperations/article/55341839/thats-the-ticket
19. Matthews Real Estate Investment Services, "Car Wash M&A / The Great Reset" (build costs; unit margins; ~6.3% cap rates; sale-leaseback structure), 2025–2026; and Innowave/HonestCasa, "Express Tunnel Car Wash Economics." https://www.matthews.com/insights/car-wash-ma
20. U.S. Environmental Protection Agency, "Managing Used Oil: Answers to Frequent Questions for Businesses" (40 CFR Part 279). https://www.epa.gov/hw/managing-used-oil-answers-frequent-questions-businesses
21. U.S. Environmental Protection Agency, "NPDES Permit Basics" and vehicle wash / rinse-water guidance (Clean Water Act). https://www.epa.gov/npdes/npdes-permit-basics
22. U.S. Environmental Protection Agency, "Regulatory Requirements for MVAC System Servicing (Clean Air Act Section 609)." https://www.epa.gov/mvac/regulatory-requirements-mvac-system-servicing
23. U.S. Federal Trade Commission, "Franchise Rule" (Franchise Disclosure Document; 23 items; 14-day rule). https://www.ftc.gov/legal-library/browse/rules/franchise-rule
24. U.S. Department of Justice, "Herfindahl-Hirschman Index." https://www.justice.gov/atr/herfindahl-hirschman-index
25. IBISWorld / U.S. Census Bureau Nonemployer Statistics — third-party market sizing that folds in nonemployer operators (order-of-magnitude complement to the employer-only federal floor, especially for 811198). https://www.census.gov/programs-surveys/nonemployer-statistics.html