Other Scientific and Technical Consulting Services (U.S.)

NAICS 2022 code 541690 · An investor's primer

NAICS = North American Industry Classification System, the federal system used to sort businesses into industries.

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1. Overview

This is the "expert-for-hire" corner of the professional-services economy: firms that sell scientific, technical, and economic judgment, usually by the hour. When a company faces a billion-dollar antitrust case, a product that catches fire, a merger the government wants to block, a utility rate proceeding, or a question about crop yields or reactor safety, it hires people in this industry to analyze the problem and, often, to testify about it.[1]

It is a broad, fragmented, expertise-led market rather than a single product category. The economics are attractive: it is high-margin, low-capital, and cash-generative. The only real asset is credentialed people, so the best operators throw off free cash and return surplus cash to their owners. Demand is also unusually durable — much of the work (litigation, regulatory enforcement, restructuring) actually rises when the economy weakens, which makes parts of this industry counter-cyclical.

Public vs. private ways in. A handful of pure-play consultancies are publicly listed — Exponent and Charles River Associates are the cleanest — and several large diversified firms (led by FTI Consulting) house sizable scientific/economic-consulting arms. But the marquee names in the most prestigious niche, economic and litigation consulting, are almost all private and employee-owned (Analysis Group, The Brattle Group, Cornerstone Research) or private-equity-owned (Guidehouse, Berkeley Research Group). Public investors mostly get indirect exposure through diversified companies; private investors can buy specialist firms outright, back consolidation platforms, or co-invest alongside the private-equity owners.

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2. What it is and how it's structured

The Census Bureau defines 541690 as establishments that advise other organizations on scientific and technical matters — except environmental.[1] It is deliberately a catch-all "other" bucket. Illustrative sub-fields include:

• Economic and litigation consulting — antitrust, damages, intellectual-property (IP) valuation, securities, transfer pricing, expert testimony. (The highest-profile, highest-margin niche.)
• Physical-science and engineering consulting — failure analysis, product-safety and recall investigations, materials, biomechanics, industrial accidents.
• Energy consulting — utility economics, grid and power-market analysis, energy-efficiency program design.
• Agricultural / agronomy / forestry / dairy-herd consulting.
• Safety, security, and defense consulting; biological, chemical, physics, and radio/audio consulting.[1]

Clients typically hire these firms to answer questions such as: Is a product or process safe? What caused a failure or accident? How should an energy or security system be designed? What are the economic or technical consequences of a decision — and will that analysis hold up in court or before a regulator?

What it excludes (and where that work lives instead). The taxonomy draws several fine lines an investor should know — this matters because many "consulting" companies sit mostly outside 541690:

Ownership mix. Overwhelmingly private. The universe runs from a few publicly listed firms, through large private-equity- and employee-owned partnerships and nonprofit research institutes, down to tens of thousands of one- and two-person specialist shops (a lone agronomist, safety consultant, or forensic engineer). Reputation and credentialed people — PhDs, professors, licensed professionals — are the franchise; there is essentially no physical plant. Of 28,043 establishments counted in 2023, roughly 23,020 (about 82%) had fewer than five employees — the statistical fingerprint of a long tail of tiny operators.[3]

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3. How big it is

Federal ground-truth figures for 541690:

SBA = U.S. Small Business Administration. Payroll of $18.3 billion against $53.5 billion of receipts shows how labor-heavy this is — compensation is the dominant cost, and much of the rest is partner profit.

Undercount caveat — the true footprint is bigger and more barbell-shaped than these tables suggest. County Business Patterns covers only establishments with paid employees; it excludes the self-employed, businesses without employees, and most government workers. The Economic Census likewise excludes non-employer businesses.[4] Two large groups therefore leak out of the 541690 tally:

1. Giant diversified consultancies (FTI Consulting, Deloitte, and others) run substantial scientific/economic-consulting practices that report under their firm's primary code, not 541690. Their expert-consulting revenue is real but doesn't land here.
2. The very smallest operators — sole-proprietor agronomists, safety consultants, and forensic specialists with no payroll — are non-employer businesses excluded from the counts.

So both the top and the tail of the industry escape the employer statistics. As a private cross-check, the research firm IBISWorld sizes a broader "Scientific & Economic Consulting" basket at about $62.3 billion for 2024 (up ~3.6% that year) — larger than the Census figure partly because of definition and vintage differences.[6] Treat the $53.5 billion Census number as the authoritative floor for the narrowly defined industry.

Concentration — fragmented, with a meaningful large-firm top. The largest four firms took just 30.9% of receipts; the top eight, 34%; the top 20, 40%; the top 50, 48.3% (2022).[2] (The Herfindahl-Hirschman Index — HHI, the standard concentration measure — is suppressed for this industry.[2]) A four-firm share near 31% spread across nearly 24,000 firms is the statistical signature of a talent-driven, low-barrier business where reputation, not scale, wins work.

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4. The investable universe

NAICS 541690 is not a clean stock-market peer group. None of the listed companies below is a pure-play 541690 investment — several are classified primarily in engineering, environmental, management, technology, or defense services. The right analysis is to weigh the share of revenue from genuinely relevant service lines, not a diversified company's entire revenue base. Tickers and scale below; valuation and yield are reserved for Section 10.

Publicly traded — best fits

EBITDA = earnings before interest, taxes, depreciation and amortization; TTM = trailing twelve months; IP = intellectual property.

Adjacent / diluted public plays (mostly outside 541690)

These do 541690-type work but are classified elsewhere, so they offer only partial exposure: Booz Allen Hamilton (BAH) and CACI International (CACI) for national-security and technical advisory (primarily management/technology and defense services); UL Solutions (ULS) for applied safety science (mostly testing and certification); and Tetra Tech (TTEK) and Montrose Environmental (MEG) for scientific/technical advisory that is largely environmental and engineering work — both explicitly excluded from 541690.

Major private and nonprofit owners

The most prestigious economic/litigation-consulting names are not public:

• Analysis Group — private, employee-owned (economics/litigation).
• The Brattle Group — private, employee-owned (energy, antitrust, finance economics).
• Cornerstone Research — private (financial/economic litigation; deep academic-expert bench).[14]
• Bates White — private (economic consulting).
• NERA Economic Consulting — subsidiary of Marsh McLennan (MMC, NYSE), inside its Oliver Wyman Group.[12]
• Compass Lexecon — part of FTI Consulting (FCN).[9]
• Guidehouse — owned by Bain Capital (acquired for ~$5.3 billion, closed December 2023; previously Veritas Capital / PwC Public Sector).[13]
• Berkeley Research Group (BRG) — private-equity-backed.
• Battelle — an independent nonprofit applied-science and technology institute — a reminder that nonprofits are meaningful players in this space.[17]

Below these sit tens of thousands of small specialist shops in agronomy, safety, security, defense, biotech, and energy.

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5. How the money works

This is a labor-led, billable-hours business, and the core identity is simple:

Revenue ≈ billable headcount × billing rate × utilization

Owners make money on the spread between what they bill for an expert's time and what they pay that expert, multiplied by how busy the staff are. Contracts come in a few shapes — time-and-materials (client pays for hours and expenses), fixed-price projects (the firm carries delivery risk), retainers and recurring compliance/monitoring work, and government contracts (often cost-reimbursement or indefinite-delivery). The levers:

• Utilization (chargeability) — the share of professional hours billed to clients. This is the single most-watched operating metric; Exponent runs around 75%.[7] Because most compensation is fixed but revenue is variable, small utilization swings move margins a lot, and idle staff or severance can compress margins quickly.
• Billing rate and realization — headline hourly rates (a senior testifying expert can bill four figures per hour) and the fraction actually collected.
• Headcount growth — the only way to add capacity; recruiting and retaining credentialed experts is the growth strategy.
• Reimbursements pass through. Firms report "revenue before reimbursements" (their actual fee income) separately from client-reimbursed expenses. Exponent's FY2024 gap: ~$518M of fees vs. ~$558M total.[7] Watch the net number.

Why margins are attractive. Almost no capital is tied up — no factories, minimal equipment. The main cost is people. That yields high returns on capital and strong free cash flow: Exponent posted a ~28.6% EBITDA margin in FY2024; CRA runs a leaner ~13% (a lower-margin economic-consulting model that pays experts more of the revenue).[7][8]

Metrics to track. Beyond utilization and realization: revenue per professional, backlog and book-to-bill, pricing versus salary inflation, employee attrition, fixed-price project margins, client concentration, contract win/renewal rates, days sales outstanding (DSO), operating cash conversion, and net debt. Note that OUR federal source file provides no industrywide utilization, margin, pricing, or cash-conversion benchmark — those come from company disclosures, not the Census.

Cyclicality is mixed and, in parts, favorable. Litigation, antitrust enforcement, and corporate restructuring generate more work in downturns, cushioning the business; energy, agricultural, and federal-program work track their own capital and budget cycles.

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6. What drives demand

• Litigation and regulatory enforcement. Antitrust cases, IP disputes, securities class actions, and product-liability suits are the biggest engine — they need economists and scientists to quantify damages and testify. Merger reviews by the Department of Justice (DOJ) and Federal Trade Commission (FTC) drive antitrust economics; leading firms compete to staff both sides of the marquee cases.[14]
• Mergers-and-acquisitions (M&A) activity. More deals → more competition reviews, valuations, and IP work.
• Technical complexity. Batteries, advanced manufacturing, biotechnology, artificial intelligence (AI), data centers, and high-consequence products create problems clients cannot solve entirely in-house.
• Product safety, recalls, and catastrophic events. Fires, crashes, structural failures, and mass-tort claims drive forensic engineering and health-science work (Exponent's core).
• The energy transition and infrastructure investment. Grid modernization, power-market reform, utility rate cases, electrification, and efficiency mandates fuel energy consulting (Willdan, ICF, CRA's energy practice).
• Government, defense, and research spending. Federal and state agencies buy analytical, technical, and security advisory support (ICF, Guidehouse). Durable, but sensitive to appropriations and procurement timing — currently a headwind (Section 9).
• Cybersecurity and AI governance. The National Institute of Standards and Technology (NIST) Cybersecurity Framework (CSF) 2.0 is widely used to manage cyber risk, generating work for security, risk, and technology advisers.[20]
• Specialized science and agriculture. Agronomy, biotech, defense, and security consulting track their end markets' own budgets and R&D (research-and-development) cycles.

AI is both a demand driver and a substitution risk — it can increase demand for validation, safety, and governance work while cutting the labor needed for generic research and reporting (Section 9).

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7. Regulation

The unusual feature here is that the consultants themselves are lightly regulated, but their work is driven almost entirely by other people's regulation.

• No single license to be a "scientific consultant." NAICS is a statistical classification, not a professional license. Unlike lawyers or professional engineers, most people in this industry need no industry-specific license; credibility comes from credentials (PhDs, academic appointments) and reputation. Some sub-fields do carry individual licensure or certification (professional agronomists, certified foresters, certain safety professionals), and specific work may require lab accreditation, security clearances, or export-control compliance.[1]
• The courtroom gatekeeper: expert-testimony rules. For litigation work, whether an expert's opinion is even admitted is governed by the Daubert standard and Federal Rule of Evidence (FRE) 702 — the latter amended effective December 2023 to tighten the judge's gatekeeping role. A firm's value rests on producing experts and analyses that survive this scrutiny.[21]
• Government-contracting rules. Firms serving federal agencies must comply with the Federal Acquisition Regulation (FAR), the government-wide procurement rulebook; defense work adds the Defense Federal Acquisition Regulation Supplement (DFARS). Terms on IP, government data, privacy, audits, conflicts, and cybersecurity directly affect margins and eligibility.[18][19]
• Demand-side regulators. Revenue is a function of enforcement intensity at the DOJ, FTC, and Securities and Exchange Commission (SEC); energy oversight at the Federal Energy Regulatory Commission (FERC) and state public utility commissions (PUCs); and workplace rules at the Occupational Safety and Health Administration (OSHA). When these agencies get more aggressive, consulting demand rises.
• Small-business thresholds. The SBA sets a $19 million average-annual-receipts size standard for 541690, which affects federal small-business contracting eligibility; it does not define the commercial market.[5]
• Independence and conflicts. Testifying-expert work demands managed conflict checks and independence; a discredited or conflicted expert is a reputational and financial liability.

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8. Competitive dynamics and consolidation

Fragmented and talent-defined. With a four-firm share near 31% across ~24,000 firms, no one dominates.[2] Barriers are low on paper — a credentialed expert can hang out a shingle — but high in practice for premium work, where a firm needs a stable of testifying experts with track records and deep relationships with the elite law firms and corporations that hire them. Large firms compete on breadth, geographic reach, cross-selling, and the ability to staff multidisciplinary projects; boutiques compete on specialist depth, speed, independence, and senior-level access.

"The assets ride the elevator down each night." People are the franchise, and star experts can move firms and take client relationships with them. This makes compensation, equity/partnership structure, and retention central to competitive position — and to risk.

Consolidation is happening at several levels:

• Private equity is rolling up the sector — Bain Capital's ~$5.3 billion purchase of Guidehouse,[13] plus PE ownership of Berkeley Research Group and others.
• Strategic acquirers add capabilities — FTI built its economic-consulting lead by absorbing Compass Lexecon; CRA and Willdan bolt on specialist boutiques.
• A broader adjacent wave is reshaping the neighboring engineering/environmental market (e.g., KKR's 2021 majority stake in ERM), which spills capital and competition into scientific consulting — but those deals sit largely outside 541690, so they are not proof that every dollar belongs here.[16]
• The prestige core resists consolidation. The top economic-consulting partnerships (Analysis Group, Brattle, Cornerstone) have stayed independent and employee-owned, because partner economics and culture, not capital, drive them.

The investment case for any roll-up ultimately turns on employee retention, pricing discipline, integration, and the durability of acquired client relationships.

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9. Risks

• Key-person / talent flight. Losing a rainmaking expert can move revenue and margins; a departing star may take clients. Compensation inflation is a persistent squeeze, especially in economic consulting, where scarce scientists and economists can capture much of the industry's pricing power.
• Utilization and demand swings. Fixed pay against variable billings means a slow quarter compresses margins quickly.
• Fixed-price execution. Overruns, rework, or bad estimates can turn a profitable contract into a loss.
• Client and end-market concentration. Heavy reliance on a few law firms, corporate clients, or a single funder (notably the federal government) raises volatility.
• Federal-budget risk — an active headwind. The 2025 government cost-cutting drive (the "Department of Government Efficiency," DOGE) and General Services Administration (GSA) pressure to cancel "non-essential" consulting have hit government-facing firms hard: ICF reported U.S.-federal revenue down ~12.6% year-over-year, with roughly $115 million of FY2025 revenue and $375 million of backlog affected; Guidehouse and Booz Allen saw contract terminations.[15] Firms tilted to federal work carry this risk; litigation- and commercial-tilted firms far less so.
• AI disruption. Generative AI compresses the research-and-analysis timelines that underpin billable-hours economics, pressuring pricing and the leverage model; buyers increasingly expect AI-enabled delivery.[16] The offsetting judgment: credentialed, courtroom-tested expert testimony is among the harder consulting outputs to automate, so the premium litigation niche looks more defensible than commodity analytical work. (Forward-looking.)
• Cybersecurity and confidentiality. Consultants often hold sensitive technical, personal, commercial, or government information; a breach is both a legal and a reputational hit.
• Reputational risk. A single high-profile expert whose testimony is excluded or discredited can damage a franchise.
• Acquisition / integration risk. Debt-funded consolidation destroys value if acquired cultures, systems, or experts fail to integrate.

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10. How to invest and the outlook

Public routes. Direct exposure is limited to a few names, mostly small- and mid-cap. Treat all of them as exposure proxies, not pure measurements of 541690, and read the service-line disclosures, government exposure, backlog quality, contract mix, utilization, attrition, client concentration, cash conversion, and acquisition history:

• Exponent (EXPO) — the purest science/engineering + expert-witness play, prized for high margins, low capital intensity, and a consistent dividend; typically valued at a premium multiple that reflects that quality.
• Charles River Associates (CRAI) — the listed economic/litigation-consulting play; lower-margin but steady, with a dividend and buybacks.
• FTI Consulting (FCN) — diversified advisory whose ~$864M Economic Consulting segment gives the largest dollar exposure to this niche, buffered (and diluted) by restructuring, forensic, technology, and communications work.[9]
• ICF International (ICFI) and Willdan Group (WLDN) — energy/government-tilted technical consulting; more federal-budget and program cyclicality.

Reserve share-price, dividend-yield, and valuation-multiple decisions for your own screening — these are liquid but thinly-followed names where quality (Exponent) trades at a premium and government-exposed names trade cheaper on budget risk.

Private routes. Because the prestige core is private, most private-market exposure is indirect: private-equity funds (Bain Capital via Guidehouse; the sponsors behind BRG), a listed parent (Marsh McLennan owns NERA), or partnership/employment at the employee-owned firms. There is no simple index for the segment. For those buying specialist firms directly, the most attractive targets combine niche high-consequence expertise, recurring compliance or monitoring work, strong credentials, low customer concentration, transferable (not founder-dependent) client relationships, and clear succession. Diligence should cover backlog, project-level profitability, receivables, contract terms, professional liability, licenses, data rights, and employee retention.

Near-term drivers (forward-looking judgments):

• Litigation, antitrust, and IP demand looks structurally firm, and its counter-cyclical bias is a cushion if the economy softens.
• The energy transition should keep energy-consulting demand growing through the decade.
• Federal spending is the key swing factor near-term — a genuine drag on government-facing firms in 2025-26, largely irrelevant to the litigation/commercial names.
• AI is both tailwind and threat — a productivity boost to margins for firms that adopt it, and a pricing/headcount risk to the billable-hours model, with the expert-testimony franchises best insulated.
• Talent economics remain the ultimate variable. In a business whose only asset walks out the door each night, the firms that recruit, retain, and monetize scarce experts will out-earn the rest.

Bottom line: constructive but uneven. This is a portfolio of specialized knowledge businesses, not one homogeneous sector. The best assets pair expert judgment with recurring work, trusted credentials, proprietary workflows, or data that clients cannot easily replace.

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Sources

1. U.S. Census Bureau. "North American Industry Classification System: 541690 — Other Scientific and Technical Consulting Services (2022 definition, examples, and exclusions)." 2022. https://www.census.gov/naics/?details=541690&input=541690&year=2022
2. U.S. Census Bureau. "Selected Sectors: Concentration of Largest Firms for the U.S.: 2022 (Economic Census), NAICS 541690 — receipts $53.5B; 23,880 firms; CR4 30.9%, CR8 34%, CR20 40%, CR50 48.3%; HHI suppressed." 2025. https://data.census.gov/table/ECNSIZE2022.EC2200SIZECONCEN?codeset=naics~541690&y=2022
3. U.S. Census Bureau. "County Business Patterns, 2023 — NAICS 541690 (28,043 establishments; 180,378 employees; $18.296B annual payroll; $4.443B Q1 payroll; ~23,020 establishments with <5 employees)." 2025. https://data.census.gov/table/CBP2023.CB2300CBP?codeset=naics~541690
4. U.S. Census Bureau. "County Business Patterns Methodology" and "2022 Economic Census FAQ" (coverage excludes non-employers, self-employed, and most government workers). 2022-2026. https://www.census.gov/programs-surveys/cbp/technical-documentation/methodology.html
5. U.S. Small Business Administration. "Table of Small Business Size Standards — NAICS 541690 ($19.0 million average annual receipts)." 2023. https://www.sba.gov/document/support-table-size-standards
6. IBISWorld. "Scientific & Economic Consulting in the US — Market Size (2024: ~$62.3B, +3.6%)." 2024. https://www.ibisworld.com/industry-statistics/market-size/scientific-economic-consulting-united-states/
7. Exponent, Inc. "Exponent Reports Fourth Quarter and Fiscal Year 2024 Financial Results (total revenue $558.5M; revenue before reimbursements $518.5M; net income $109.0M; EBITDA margin 28.6%; ~75% utilization)." 2025. https://investors.exponent.com/investors/news-events/news-details/2025/Exponent-Reports-Fourth-Quarter-and-Fiscal-Year-2024-Financial-Results/default.aspx
8. CRA International, Inc. "Charles River Associates (CRA) Reports Fourth-Quarter and Full-Year 2024 Financial Results (revenue $687.4M, +10.2%; non-GAAP EBITDA $90.4M / 13.2%)." 2025. https://ir.crai.com/news-releases/news-release-details/charles-river-associates-cra-reports-fourth-quarter-and-full-6/
9. FTI Consulting, Inc. "FTI Consulting Reports Fourth Quarter and Full Year 2024 Financial Results (total revenue $3.699B; Economic Consulting segment $863.6M)." GlobeNewswire, 20 Feb 2025. https://www.globenewswire.com/news-release/2025/02/20/3029543/33891/en/FTI-Consulting-Reports-Fourth-Quarter-and-Full-Year-2024-Financial-Results.html
10. ICF International, Inc. "ICF Reports Fourth Quarter and Full Year 2024 Results (total revenue $2.02B, +2.9%)." 2025. https://investor.icf.com/news-releases/news-release-details/icf-reports-fourth-quarter-and-full-year-2024-results
11. PitchBook. "Willdan Group — Company Profile (trailing-12-month revenue ~$684M)." 2026. https://pitchbook.com/profiles/company/42077-80
12. Umbrex / Consultancy.org. "Profile of NERA Economic Consulting — wholly owned subsidiary of Marsh McLennan (Oliver Wyman Group)." 2024. https://umbrex.com/resources/profiles-of-the-top-consulting-firms/overview-profile-and-history-of-nera-economic-consulting/
13. Bain Capital. "Guidehouse to be Acquired by Bain Capital Private Equity (~$5.3B; closed December 2023; formerly Veritas Capital)." 2023. https://www.baincapital.com/news/guidehouse-leading-global-provider-consulting-services-be-acquired-bain-capital-private-equity
14. Cornerstone Research. "Antitrust & Competition practice (economic-consulting demand from antitrust enforcement, merger review, and expert testimony)." 2025. https://www.cornerstone.com/practices/services/antitrust-competition/
15. Washington Technology. "DOGE- and GSA-driven federal consulting cuts — ICF U.S. federal revenue -12.6%, ~$115M FY25 revenue and $375M backlog affected; Guidehouse and Booz Allen contract terminations." 2025. https://www.washingtontechnology.com/companies/2025/04/industry-layoffs-mount-cancelled-contracts-and-doge-efforts-take-hold/404304/
16. Consultancy.me / IBM Institute for Business Value. "How AI and generative AI will transform the consulting industry (buyers seek AI-enabled services; knowledge-work timeline compression)." 2025-2026. https://www.consultancy-me.com/news/10130/how-ai-and-gen-ai-will-transform-the-consulting-industry
17. Battelle. "Who We Are (independent nonprofit applied-science and technology institute)." 2026. https://www.battelle.org/who-we-are
18. Acquisition.gov. "Federal Acquisition Regulation (FAR)." 2026. https://www.acquisition.gov/browse/index/far
19. Acquisition.gov. "Defense Federal Acquisition Regulation Supplement (DFARS)." 2026. https://www.acquisition.gov/dfars
20. National Institute of Standards and Technology. "The NIST Cybersecurity Framework (CSF) 2.0." 2024. https://www.nist.gov/publications/nist-cybersecurity-framework-csf-20
21. U.S. Courts. "Federal Rules of Evidence — Rule 702 (Testimony by Expert Witnesses; amended effective December 1, 2023)." 2023. https://www.uscourts.gov/rules-policies/current-rules-practice-procedure/federal-rules-evidence