FactHub reusable chart

Washington's gasoline premium tracked carbon allowance costs, 2023-2026

Quarterly Washington-specific gasoline price premium (vs. a 7-state comparison group, relative to 2015-2022) and the auction-implied carbon cost per gallon, 2023Q1-2026Q3, in January 2024 dollars.

Credit: FactHub Research Team; prices from EIA, auction prices from Washington Dept. of Ecology, emission factors from EPA.

Node: chart:wa-cca-premium-vs-carbon-cost:1

Send feedback on this chart

Line chart of two quarterly series from 2023 through the third quarter of 2026, in cents per gallon. "Carbon cost" (auction-implied carbon cost per gallon) starts near 39 cents, peaks near 50 in mid-2023, falls to about 20-23 cents in 2024, rises to about 53 cents in late 2025, and drops to about 29 cents in 2026Q3. "WA premium" (measured Washington premium vs. 7 states) starts near 2 cents in 2023Q1, rises to about 64 cents in 2023Q3, falls to about 12 cents in 2024Q3, rises to about 57 cents in 2025Q3, and is about 39 cents in 2026Q3. The two lines rise and fall together. — Across 15 quarters, Washington's gasoline premium over a 7-state comparison group averaged 38.7 cents per gallon, nearly identical to the average carbon cost implied by allowance auctions (38.9 cents). Both fell sharply in 2024, when allowance prices collapsed while a repeal initiative was pending, and rose again in 2025. A regression slope of about 1.0 is consistent with drivers paying essentially the full carbon cost, though the premium also reflects other Washington-specific factors.

What this chart asks

Did the measured Washington gasoline premium move with the carbon allowance price quarter by quarter?

Why it is shown this way

A quarterly line chart matches the auction frequency, so each carbon-cost point corresponds to one auction.
Both series use the same unit (cents per gallon, January 2024 dollars) on one axis, so no dual axis is needed.
The y-axis starts at zero to avoid exaggerating differences.
Series names are short ("Carbon cost", "WA premium") so direct labels fit; the description and alt text define them.

Chart annotations

These markers provide relevant context for interpreting the chart. Their timing or position does not, by itself, establish causation.

Cap-and-invest began: January 1, 2023
Climate Commitment Act compliance obligations began January 1, 2023.
Voters rejected repeal (I-2117): November 5, 2024
Allowance prices were depressed while the repeal initiative was pending and recovered after it failed.

Data and accessibility

Download chart data · Open accessible table · Download PNG · Download SVG

Dataset wa-cca-gasoline-price-premium-2015-2026, analysis quarterly-long-series

Sources

This chart draws on the sources of the dataset versions it visualizes.

Washington Gasoline Price Premium and Carbon Allowance Costs, 2015-2026

U.S. Energy Information Administration, weekly retail gasoline prices Principal source of weekly prices for Washington and comparison regions.
Retrieved October 9, 2026. U.S. federal government data. Retrieved files are identified by digest in source-manifest.json; curated values redistributed with attribution to EIA.
BLS CPI-U (CPIAUCSL) via Federal Reserve Bank of St. Louis FRED Inflation adjustment.
Retrieved October 9, 2026. U.S. federal government data. Factor values redistributed with attribution.
EPA 40 CFR Part 98 Subpart MM, Table MM-1 default factors CO2 emission factors for gasoline (8.78 kg/gal) and diesel (10.21 kg/gal).
Retrieved October 9, 2026. U.S. federal regulation. Linked as a public record; source bytes are not redistributed in this release.
Washington Transportation Revenue Forecast Council, Feb 2026 forecast, Vol. II, Table A.1 Taxed gasoline and diesel gallons by fiscal year.
Retrieved October 9, 2026. Washington State public record. Linked as a public record; source bytes are not redistributed in this release.
Washington Dept. of Ecology, Clean Fuel Standard 2024 Progress (Pub. 26-14-043), Table 2 State-commissioned 2023-2024 estimates used in replication-check.
Retrieved October 9, 2026. Washington State public record. Linked as a public record; source bytes are not redistributed in this release.
Ecology, Cap-and-Invest Auction Revenue Forecast Summary, Nov 2023 2023Q1-Q3 settlement prices.
Retrieved October 9, 2026. Washington State public record. Linked as a public record; source bytes are not redistributed in this release.
Ecology, Auction #4 Summary Report, Dec 2023 2023Q4 settlement price.
Retrieved October 9, 2026. Washington State public record. Linked as a public record; source bytes are not redistributed in this release.
S&P Global Commodity Insights, Washington auction prices drop sharply (Mar 2024) 2024Q1 settlement price (secondary).
Retrieved October 9, 2026. News report. Linked as a public record; source bytes are not redistributed in this release.
Ecology Revenue Forecast Summary June 2024 (copy hosted by Washington Research Council) 2024Q2 settlement price (secondary host).
Retrieved October 9, 2026. Washington State public record. Linked as a public record; source bytes are not redistributed in this release.
Ecology, Auction #7 Summary Report, Sep 2024 2024Q3 settlement price.
Retrieved October 9, 2026. Washington State public record. Linked as a public record; source bytes are not redistributed in this release.
Environmental Defense Fund, Climate 411, Mar 12 2025 2024Q4 and 2025Q1 settlement prices (secondary).
Retrieved October 9, 2026. Advocacy blog. Linked as a public record; source bytes are not redistributed in this release.
Ecology, Auction #10 Summary Report, Jun 2025 2025Q2 settlement price.
Retrieved October 9, 2026. Washington State public record. Linked as a public record; source bytes are not redistributed in this release.
Ecology news release, Sep 10 2025 2025Q3 settlement price.
Retrieved October 9, 2026. Washington State public record. Linked as a public record; source bytes are not redistributed in this release.
Ecology, Auction #12 Summary Report, Dec 2025 2025Q4 settlement price.
Retrieved October 9, 2026. Washington State public record. Linked as a public record; source bytes are not redistributed in this release.
Environmental Defense Fund, Climate 411, Mar 11 2026 2026Q1 settlement price (secondary).
Retrieved October 9, 2026. Advocacy blog. Linked as a public record; source bytes are not redistributed in this release.
Environmental Defense Fund, Climate 411, Jun 10 2026 2026Q2 settlement price (secondary).
Retrieved October 9, 2026. Advocacy blog. Linked as a public record; source bytes are not redistributed in this release.
Ecology, Auction #15 Summary Report, Sep 2026 (Pub. 26-14-063) 2026Q3 settlement price ($39.50, auction held 2026-09-02).
Retrieved October 9, 2026. Washington State public record. Linked as a public record; source bytes are not redistributed in this release.
Washington Legislature, ESSB 5987 (2015), session law Enacted 7-cent (Aug 1 2015) and 4.9-cent (Jul 1 2016) increases from a 37.5-cent base to 49.4 cents.
Retrieved October 9, 2026. Washington State public record. Linked as a public record; source bytes are not redistributed in this release.
OPB, Washington gas tax increase July 1 2025 July 2025 increase from 49.4 to 55.4 cents.
Retrieved October 9, 2026. News report. Linked as a public record; source bytes are not redistributed in this release.
Washington State Standard, gas tax inflation adjustment July 2026 adjustment to about 56.5 cents.
Retrieved October 9, 2026. News report. Linked as a public record; source bytes are not redistributed in this release.

Limitations

The measured premium captures all Washington-specific factors relative to the comparison group, not only the Climate Commitment Act.
Placebo tests show single-year pre-policy deviations of up to about 20 cents per gallon; single quarters are noisier still.
2023Q1 shows almost no premium; compliance costs may not have reached retail prices in the first quarter.
Close tracking is consistent with full pass-through but does not by itself prove causation.
The comparison group (CO, TX, FL, MN, OH, NY, MA) excludes Oregon and Idaho, for which EIA publishes no weekly series.

Articles and datasets using this chart

Article Washington's carbon market has added 24 to 46 cents a gallon to gasoline.

Version details

The exact citing versions, and the version of this chart each cites.

Article wa-cca-gas-price-effect — version 2 (published) cites version 1
Article wa-cca-gas-price-effect — version 1 (published) cites version 1