Externality Limiter: The Pricing Principle
Engine: Engine 6
Framing
Externalities are quantifiable harms currently dumped free on society. Carbon emissions. Methane leakage. Systemic financial risk. Pavement destruction. Aquifer depletion. Tobacco and sugar public health costs. Firearms violence. Algorithmic toxicity. The Accord prices these at source, captures revenue, and either returns it to households (dividend) or routes it to remediation funds (trust). Pricing is the mechanism; regulation is avoided where pricing works.
Forward-looking and retrospective externalities
The fifteen priced externalities below are forward-looking — they price harms ongoing and anticipated. The Accord also recognizes one retrospective externality that does not appear in the list because it is not amenable to pricing at source: the unpaid caregiving externality. Decades of unpaid care work captured by the broader economy, with the costs absorbed by caregivers (disproportionately women) who entered old age with sharply reduced Social Security accruals. The Accord prices it backward in the only available form — retroactive equity, paid out as the Dignity Floor (Chapter 14, $1,150/month for ~5.5 million low-income retirees, ~$13B/yr). Forward-looking caregiving is priced through Universal Child Allowance, the childcare mandate, and family policy.
The fifteen priced externalities
1. Carbon (CO₂-equivalent) — $80/ton escalating $30/year to $680 cap; household dividend up to $160/ton, excess to Climate Adaptation Trust
2. Methane (Methane Accountability and Reduction Levy) — $1,200/ton escalating $240/year to $2,880 ceiling; three source categories; routing detailed in Chapter 10
3. too-big-to-fail bank (systemic financial institution risk) — risk-weighted levy on too-big-to-fail institutions; revenue to Financial Stability Reserve
4. Pavement destruction — Mileage-Based Weight Fee (detail below)
5. Aquifer depletion — $50 per acre-foot above sustainable yield thresholds; escalated annually with CPI
6. Tobacco — federal excise at $15/pack. Tobacco's downstream cost falls on Distributed Healthcare; pricing it at source is now justifiable on Pigouvian grounds because the federal balance sheet bears the medical bill
7. Sugar (added sugar, beverages) — $0.02 per gram added sugar in beverages, calibrated to current soda-tax literature (Berkeley, Mexico, UK studies)
8. Firearms violence — 10% excise on ammunition, 5% excise on firearms. The trauma-care burden falls on Distributed Healthcare, whose trauma capacity is being expanded; pricing the externality at source is the Pigouvian counterpart. Sunset clause if violent-injury costs fall 20% from baseline
9. Algorithmic toxicity — disclosure and National Statistics Board measurement only at launch; no fee until Digital Online Safety Board-National Statistics Board privacy thresholds are set and algorithmic-harm index methodology is published
10. Plastic — EPA cost-benefit determination; placeholder $0.05/lb production levy pending peer-reviewed cost-of-externality studies
11. Noise pollution — EPA cost-benefit; placeholder airport/transportation levy in affected zones pending acoustic-health literature review
12. Airborne particulates — EPA cost-benefit; placeholder emission-weighted levy pending updated PM2.5 mortality studies
13. Ultra-processed food (NOVA 4 category) — per-kilogram excise on packaged foods exceeding defined thresholds for NOVA 4 classification. Restaurants and whole foods exempt to keep administration simple
14. Agricultural nitrogen surplus and low-dose antibiotic use — nitrogen surplus fee above agronomic need (verified through existing USDA nutrient management plans); low-dose antibiotic use fee in animal agriculture with documented-therapeutic-use exemption. The nitrogen burden falls on water-quality infrastructure; the antibiotic burden falls on Distributed Healthcare's antimicrobial-resistance load — pricing both at source is the Pigouvian counterpart
15. Urban congestion and curb pricing — federal framework enabling municipal congestion pricing (not preempting it); 50% of net revenue returned to locality via Infrastructure Decay Fund, 50% to transit capital; federal highway funding approval not conditioned on, or revoked because of, local implementation
All rates reviewed on a 3-year cycle by the relevant Expert Board (American Healthcare Quality Board for healthcare-linked externalities; EPA-National Statistics Board joint review for environmental externalities; Digital Online Safety Board for algorithmic; Financial Stability and Disbursement Board for too-big-to-fail bank; USDA joint review for agricultural externalities). Rates adjust to published cost-of-externality studies with citations in the Federal Register.
Externality 4: Pavement — Mileage-Based Weight Fee
The Mileage-Based Weight Fee replaces the federal gasoline tax. It has two components plus a modal parity subsidy:
Road repair component — Per-vehicle-mile fee calibrated to the fourth power of summed axle weight. This reflects the physics of pavement damage — a fully-loaded 5-axle truck imposes approximately 10,000× the pavement damage of a passenger car. Paid primarily by heavy freight; ensures modal equity with freight rail, which pays full infrastructure costs.
Road maintenance component — Per-vehicle-mile base fee applied to all vehicles for general road maintenance. Independent of axle weight; a usage-based substitute for the gas tax that captures electric and hybrid vehicles which currently free-ride on road funding.
Transit and rail parity subsidy — A fraction of road-use revenue funds mass transit and intercity and freight rail at equivalent per-passenger-mile or per-ton-mile subsidy. Prevents the current structural bias where highways are subsidized from general revenue while transit is expected to fund itself from fares. This is the single most important modal equity correction in 70 years of US surface transportation policy.
Revenue routing: road repair and maintenance components to Infrastructure Decay Fund; parity subsidy to Transit Parity Fund (transit and rail).
Revenue routing architecture
Externality revenue has two architectural destinations:
Household dividend — When the externality is paid by households in proportion to consumption (carbon up to the rebate cap), revenue flows back to households as a universal stipend. This preserves progressivity — lower-income households consume less and receive more in stipend than they pay in embedded price.
Ring-fenced trust (only two) — Two trusts are statutorily ring-fenced because the underlying externality requires multi-decade remediation capital insulated from annual appropriation politics: the Climate Adaptation Trust (carbon revenue above the household rebate cap, plus methane levy receipts) and the Financial Stability Reserve (too-big-to-fail bank levy). All other externality revenue — water-extraction fee, public-health excises, agricultural levies, and the rest — flows to the General Fund alongside every other federal receipt. The Accord deliberately avoids trivial earmarks: where a tax goes is the General Fund unless the architecture requires otherwise, and the architecture requires otherwise in only two places.
Why pricing over regulation
Regulation requires the state to specify what behavior is permitted and enforce compliance. Pricing requires the state to specify what the externality costs and let markets adjust. Pricing is simpler, more progressive (with dividend), and more effective at the margin.