What is more airline service actually worth to Sonoma County?

By Malcolm Crawford

A claim about the whole airport gets used to settle a question about one part of it

Two ambiguities run through Sonoma County's economic case for commercial air service. Figures for "the airport" are readily heard as figures for airline service. Figures for "economic impact" are readily heard as figures for economic benefit. Neither follows from the figure alone.

The first conflation is easy to see. In ordinary use, "the airport" means commercial flights — Alaska, American, Southwest, the terminal, the departures board. In the figures used to support its economic value, "the airport" is used to mean everything at STS: airlines, general aviation, flight schools, maintenance businesses, charter operators, emergency services, and construction.

In practice, the conflation works in one direction. A claim that the airport supports 1,700 jobs does not naturally conjure flight instructors and hangar mechanics. In public discussion, the number attaches itself to the most visible part of the operation, which happens to be the contested part. A figure about the whole airport becomes, without anyone deciding to make it so, an argument for more scheduled flights.

The second is more subtle. "Economic impact" sounds much like "economic benefit," but the two measure different things. Economic impact measures the activity associated with something; economic benefit measures how much better off people are because that thing exists. An impact study can count jobs and spending associated with STS without showing how much of that activity exists because of airline service, or whether the benefits exceed the costs.

That STS as a whole provides valuable functions to Sonoma County isn't in question. The narrower question is what scheduled passenger service adds, what that addition is worth, and whether anyone has weighed it against what it costs. No single document answers that. What follows separates those questions, sets out what the public record establishes, and identifies where it stays silent.

Most airport activity is not airline activity

Airline flights are a minority of the traffic at STS. In 2025, the airport had 334 based aircraft and recorded almost 80,000 aircraft operations — the FAA counts each takeoff or landing as one operation. FAA traffic-control data classified just over 10,000 of those as air carrier operations and another 10,000 as air taxi — a mixed category that includes some smaller scheduled airline aircraft alongside charter and other commercial flights. The remaining nearly 59,000 movements were classified as itinerant general aviation, local civil, or military operations. So even counting every air taxi movement as airline activity, which overstates it, the two represent just over a quarter of all operations.

The airport's on-site partners include two fixed-base operators, two flight schools, a helicopter operator, charter and maintenance businesses, an air museum, a Civil Air Patrol squadron, REACH Air Medical Services, and a CAL FIRE air attack base. None of that requires a commercial passenger operation.

By way of comparison, Napa County Airport holds no FAA Part 139 certificate — the federal certification needed for conventional scheduled airline service — and has no such service. (It does have seasonal public charter flights under a different regulatory arrangement.) Its airport authority lists CAL FIRE, the California Highway Patrol, and REACH among regular users, and identifies medical transport, search and rescue, and wildfire response among the services it supports. It has 170 based aircraft and recorded over 65,000 operations in 2024, roughly four-fifths of the movement count at Santa Rosa.

Two wine-country airports, an hour apart, supporting many of the same categories of emergency aviation. One hosts conventional scheduled airlines. One doesn't. So a figure for the whole airport is not a figure for airline service.

From here on, the question is airline service.

The convenience is real, but its reach is limited

The clearest direct benefit of commercial service at STS is saving time. For many Sonoma County residents, using San Francisco or Oakland adds roughly an hour of driving each way compared with STS — a modest addition to a transcontinental journey, but a substantial one on a short trip to southern California. For the passengers it serves, having the airport close to home has real value. The harder question is how many travelers receive that benefit.

A study presented to the county's aviation commission in November 2021 estimated that the airport's service area generated about 7,211 passenger journeys a day in each direction. Only 7 percent started or ended at STS. Most of the rest used San Francisco or Oakland. That low share wasn't an artifact of drawing the service area too widely. The airport's own 2018 estimates showed it capturing about 5 percent of bookings across the full region, and only 12.2 percent even within Sonoma County itself. San Francisco alone took more than 80 percent of the wider market. Passenger traffic has grown substantially since; no later study of the same kind appears in the record.

The same study found that 56 percent of travelers in the service area were visitors, predominantly coming to wine country. In principle that sounds like a large untapped market, but it isn't one market — it's fragmented across the country. Serving it would mean a nonstop from Santa Rosa to each major origin city, which describes an airport several times the size of the one Sonoma County has. Short of that, each new route reaches one slice of the visitors, unless the airport can offer connections attractive enough to compete with San Francisco or Oakland.

Thus the convenience is real, but historically it has reached only a minority of the region's travelers. Most have found their air connectivity somewhere else. That raises a question the county has not yet studied — whether some of the same convenience could be provided by improving the ground connection into a much larger airport network, rather than by adding routes one at a time at Santa Rosa. A satellite terminal, connecting local passengers by ground to a larger airport, is one possible model.

Early fare data show little airport-wide effect

Southwest's arrival on 7 April 2026 made one claimed benefit directly testable: lower fares.

In the first two months, Southwest's four routes were cheaper than the comparable Bay Area alternative, by as much as about $31 each way to Burbank. That's real. But most fares on that route fell between about $65 and $230 over the same period — a spread of $165, against a $31 gap between airports. For a price-sensitive traveler, variation between fares on the same route can matter more than the choice of airport. And two months is too little to show the discount will last.

Across the airport's wider nonstop network the result is less dramatic. Federal ticket data — the Bureau of Transportation Statistics' DB1C, a 40 percent sample of domestic tickets — show fares generally within a few dollars of the cheaper San Francisco or Oakland option once the monetary cost of driving south is included, across routes covering about 91 percent of the relevant passenger volume.

So far, Southwest appears to have made its own routes somewhat cheaper. There is little evidence yet of a broader reduction in the cost of flying from Santa Rosa. The full method is published separately.

Airline service has observable effects. Their value to the county is harder to establish

Some effects of commercial airline service are straightforward. What those effects amount to as an economic benefit to Sonoma County is a different question.

The jobs figures illustrate the problem. At least four numbers have circulated: 164, 414, 479, and 1,700. One is mainly construction employment from a capital improvement plan. One attributes jobs to a single airline's five daily flights. One forecasts jobs from the runway-extension project approved in 2012. The largest appears in a 2025 civil grand jury report with no identifiable supporting source. All can end up quoted simply as "airport jobs." But none provides the number that matters here: how many jobs in Sonoma County depend on scheduled airline service. Whole-airport employment includes businesses that would remain if the airlines stopped flying tomorrow, and the public figures don't separate them.

Avelo Airlines provides one of the few airline-specific employment figures in the record, and shows that even real airline jobs are not necessarily durable. In January 2024 the county announced that Avelo's new Santa Rosa crew base was expected to create up to 50 local jobs. On opening day that May the airline reported 32 hired. The base closed in May 2025, and Avelo left the airport altogether that August, citing low demand and financial results that had proven harder to achieve than expected. Those jobs were real. So was their disappearance.

Napa has a wine-country visitor economy of roughly the same scale as Sonoma County's, without traditional scheduled airline service at its airport. In 2008 the county adopted an airport master plan that explicitly made no provision for it, and nearly two decades later the airport still lacks the Part 139 certification conventional airlines require. That doesn't show STS contributes nothing to tourism. It does show that a successful wine-country visitor economy doesn't depend on conventional scheduled airline service at its county airport.

What's obvious is the direction of some effects. More flights can make travel more convenient, employ some people, bring some visitors through the terminal, and generate more revenue for the airport itself. What isn't obvious is how much of the claimed economic benefit comes from airline service, how much additional activity it creates, how long those benefits last, who receives them, or what remains after the costs are counted.

Even the county itself has never treated those benefits as self-evident. It has repeatedly paid consultants to estimate what future growth might produce. What is missing is the corresponding look backward: once the growth occurred, how much of the predicted benefit actually appeared?

The forecasts became testable, and nobody appears to have tested them

Several forecasts have been attached to expansion at STS over the past fourteen years. The airport's economic case for expansion has relied heavily on forward-looking estimates — what growth might produce — rather than retrospective checks on whether earlier forecasts came true. Simple forecasts can be checked directly against what happened. The harder question of whether passenger growth actually produced broader economic gains received one substantial retrospective examination, but that got only as far as an association it explicitly declined to treat as causal.

In January 2012 the Board of Supervisors approved an airport master plan whose central project was lengthening the main runway to accommodate regional jets. The extended runway opened in 2014. The forecast attached to the project was unusually specific: twelve daily departures by 2015 were projected to produce another $170 million in economic impact and 479 jobs.

The timetable slipped, but the traffic target was eventually reached. A 2021 case study of the airport, prepared for the national Airport Cooperative Research Program, records about 12 scheduled flights a day at STS in 2019, and passenger traffic has since risen well beyond its 2019 level. The traffic level attached to the forecast eventually happened. The obvious next question is whether the promised $170 million and 479 jobs happened too.

No answer appears in the public record.

That is not because the airport stopped commissioning economic analysis. An earlier airport-funded analysis assigned roughly $9.5 million in annual revenue to each new nonstop market. It didn't say whose revenue — the airport's, local businesses', or the regional economy's. The later case study records that the analysis was funded to demonstrate the runway project's value to regional stakeholders, and that winning their support was important to getting the project built.

The airport's 2025 advertising media kit provides a simple example of a forecast that can be checked directly. It projected more than 850,000 passengers for the year. The actual total was 780,637 — growth of about 1 percent, rather than the roughly 10 percent needed to reach the projection. Forecasts miss, and that isn't remarkable. The point is that passenger traffic is observable, so the forecast can simply be compared with what happened.

The economic forecasts are harder to test, because jobs and regional growth have many causes. The exception was the 2021 Airport Cooperative Research Program case study, which neither the airport nor the county paid for. It examined the relationship between STS passenger traffic and regional employment from 2014 to 2019.

It did find a strong correlation between the two. However, the study then repeated the comparison using only industries it considered particularly reliant on commercial aviation. The result was almost identical — 0.956, against 0.970 for employment overall — which the study described as "essentially unchanged." In other words, the link between passenger traffic and employment was no stronger in the industries it considered most dependent on air service than across the economy as a whole. And a correlation, however strong, is still only evidence of a relationship, not a measure of economic benefit. The study itself warned explicitly that correlation did not establish causation — economic growth could be producing more passenger traffic rather than the reverse. So the analysis did not establish how much employment, if any, airline service caused, how much of that employment was genuinely additional, or whether the overall economic effect was a net benefit or a net cost.

So the simplest forecast could be checked, and missed. The most substantial retrospective analysis found a relationship but couldn't establish what caused it. What still doesn't appear in the record is a test of the expansion's central economic promises — the jobs and the economic impact it was supposed to produce.

Economic impact counts activity, not net benefit

The second ambiguity named at the outset is the difference between economic impact and economic benefit. It matters because only the latter tells you whether the overall result is a net benefit or a net cost. An impact study can be perfectly accurate and still leave that question unanswered, because economic impact and benefit-cost analysis answer different questions. Economic impact counts activity associated with the airport: passenger spending, jobs, wages, business output, and the further activity those expenditures are modeled to generate. Benefit-cost analysis asks something harder — what would be different if the service did not exist?

That distinction matters especially at STS, because most travelers in its service area already use San Francisco or Oakland. A visitor who flies into Santa Rosa and spends $1,000 in Sonoma County appears in an impact study as $1,000 of activity associated with the airport. If that visitor would otherwise have flown into San Francisco, driven north, and spent the same $1,000, the flight didn't create the spending. It changed how the visitor arrived.

Jobs and rental-car activity can work the same way. Moving a transaction from one airport to another can raise the measured economic impact of STS without creating an equivalent amount of new activity. Some of the gain may simply have moved from somewhere else. The economic benefit is the difference between the two outcomes: activity that would not otherwise have occurred, time or money genuinely saved, or resources used more efficiently.

Benefits are only one side of the calculation. Additional service also costs something — the resources spent providing it, and effects such as noise and emissions borne by people who aren't flying. Only when incremental benefits and incremental costs are set against each other can the question be answered.

FAA guidance is explicit. Regional employment and similar macroeconomic effects are difficult to quantify and frequently represent transfers from other regions. It notes that Office of Management and Budget Circular A-94 generally excludes multiplier effects — the modeled knock-on effects of spending — from benefit-cost analysis, permitting them only in limited circumstances, and that changes in employment and output are not themselves measures of social benefits or costs. The FAA's own example is infrastructure at one airport drawing operations from another: the transfer isn't the benefit — the benefit is whatever real resources the change saves.

The county is still commissioning impact studies, not net-benefit analysis

In July 2026 the Board of Supervisors approved a new air service development agreement, with $373,006 in task orders already authorized. One task order commissions another study using IMPLAN, a standard impact-modeling package, covering direct, indirect, and induced effects on jobs, output, income, and taxes, plus materials to "highlight the impacts in presentations and on the Airport's website."

The task order does not ask whether previous forecasts were right, what activity would have happened anyway, or whether the benefits exceed the costs.

The agreement is paid from the Airport Enterprise Fund. The revenues from additional airline service flow into that fund too. A June 2026 report to the Board projected $1,467,912 in new annual fees from Southwest. Across all its planned new rents and fees, including non-airline sources, the airport expected more than $2.5 million in additional recurring revenue by 2028.

For Southwest, the airport has forecast its own additional revenue to the dollar: $1,467,912 a year. No comparable estimate appears in the public record for what additional airline service is worth to Sonoma County once the costs are counted.

No analysis puts the costs and the benefits in the same ledger

Noise, emissions, and community impacts are assessed in environmental reviews. Jobs, spending, and airport revenue are counted in economic impact studies.

They stay separate. No public analysis in the record asks the final question: once the incremental benefits and costs are put on the same footing, is additional airline service a net benefit to Sonoma County?

What the record shows, and what it doesn't

The airport's role in wildfire response and emergency medicine is real, but Napa demonstrates it doesn't require a commercial-service airport.

The convenience of flying nonstop is real too. But it reaches a limited share of the region's travelers, and the alternatives to providing that connectivity haven't been examined.

The public record provides much less evidence for broader countywide economic benefit. Tourism spending attributed to the airport may simply be spending by visitors who would otherwise have arrived through San Francisco or Oakland. The headline jobs figures are forecasts, modeled estimates, or whole-airport claims, not demonstrated net new employment attributable to airline service, and the clearest observed case of airline job creation ended when Avelo left. Additional airport revenue strengthens the Airport Enterprise Fund; it is not itself evidence of an equivalent gain to the county economy.

The available evidence doesn't establish that increased commercial air service delivers a significant net economic benefit to Sonoma County. It may. But across fourteen years of expansion, repeated economic-impact studies, and continued airline recruitment spending, no readily available retrospective analysis asks whether the promised benefits actually materialized. And even if fully realized, the forecast of 479 jobs would amount to less than a quarter of one percent of employment in the Santa Rosa–Petaluma area.

The benefits have been estimated. The costs have been assessed. Nobody appears to have performed the subtraction.

Sources

The airport and its traffic

• FAA, Air Traffic Activity Data System (ATADS), Airport Operations: Standard Report, Facility STS, January 2011–June 2026. https://www.aspm.faa.gov/opsnet/sys/airport.asp — Calendar year 2025: 10,112 air carrier, 10,321 air taxi, 29,898 itinerant general aviation, 227 itinerant military, 28,646 local civil, 67 local military; 79,271 total operations. Query instructions: https://www.faa.gov/newsroom/airport-operations-and-ranking-reports-using-air-traffic-activity-data-system-atads
• FAA, National Plan of Integrated Airport Systems 2025–2029, Appendix A. https://www.faa.gov/sites/faa.gov/files/airports/planning_capacity/npias/current/ARP-NPIAS-2025-2029-Appendix-A.pdf — 334 based aircraft at STS.
• Charles M. Schulz–Sonoma County Airport, airport partners. https://sonomacountyairport.org/business-and-community/doing-business/partners/
• Charles M. Schulz–Sonoma County Airport, passenger numbers. https://sonomacountyairport.org/about-sts/passenger-numbers/

Napa County Airport

• Napa County, Airport Approach: frequently asked questions. https://connect.napacounty.gov/AirportApproach/frequently-asked-questions
• Napa County Airport Master Plan, March 2007. https://www.napacounty.gov/DocumentCenter/View/1985/Napa-County-Airport-Master-Plan-PDF — "No scheduled air carrier (passenger) or commuter airline service is anticipated at this time… Therefore, no provision for airline service has been made in this plan."
• Napa County Board of Supervisors, minutes of 15 April 2008, Resolution R-08-59 adopting the updated Airport Master Plan. https://napa.granicus.com/MinutesViewer.php?clip_id=135&doc_id=d1f5c629-21aa-4191-a106-5cb3a219de4c&view_id=2

Where the region's travelers fly from

• Sonoma County Aviation Commission, minutes of 18 November 2021: passenger leakage study prepared by Crawford, Murphy & Tilly. https://sonomacountyairport.org/wp-content/uploads/02-Minutes-Nov-21.pdf — 7,211 passengers per day each way in the catchment area; 7 percent using STS, the remainder largely using San Francisco or Oakland; Southwest carrying the most catchment passengers despite not then serving STS; 56 percent of catchment travelers visitors, predominantly to wine country, who generally did not use STS. Approval of those minutes is recorded in the Commission's minutes of 20 January 2022: https://sonomacountyairport.org/wp-content/uploads/02-Minutes-Jan-22.pdf
• Airport Cooperative Research Program, Charles M. Schulz Sonoma County Airport: Expanding Services in the Shadow of Large Competitors, 2021. https://crp.trb.org/acrpwebresource12/wp-content/uploads/sites/25/2021/08/Charles-M.-Schulz-Sonoma-County-Airport-Case-Study.pdf — 2018 airport estimates of booking capture by county (Sonoma 12.2 percent, catchment-wide about 5 percent, San Francisco over 80 percent); average daily flights in 2019; the $9.5 million per new nonstop market analysis and the purpose for which it was funded; correlations of 0.970 and 0.956 between passenger traffic and regional employment, described as "essentially unchanged"; the caution that correlation does not establish causation.

Fares

• US Bureau of Transportation Statistics, Origin and Destination Survey Data (Market), DB1C. https://www.bts.gov/topics/airlines-and-airports/origin-and-destination-survey-data-market
• Method, findings, and script: STS fare comparison: method and findings

Jobs and economic impact figures

• Charles M. Schulz–Sonoma County Airport, master plan frequently asked questions. https://sonomacountyairport.org/about-sts/master-plan/frequently-asked-questions-faq-deir-and-master-plan/ — the forecast of $170 million in economic impact and 479 jobs, conditional on twelve daily departures by 2015.
• Charles M. Schulz–Sonoma County Airport, master plan. https://sonomacountyairport.org/about-sts/master-plan/ — Board of Supervisors approval, 24 January 2012.
• Sonoma County Board of Supervisors, 2011: Tri-Star Marketing Airport Economic Impact Review, attributing approximately $112 million a year and 414 jobs to Horizon's five daily flights. https://sonoma-county.granicus.com/MetaViewer.php?clip_id=186&meta_id=70238&view_id=2
• Charles M. Schulz–Sonoma County Airport, modernized air terminal. https://sonomacountyairport.org/sonoma-county-airport-unveils-modernized-air-terminal/ — capital improvement plan employment and output figures.
• Sonoma County Civil Grand Jury, Sonoma County Airport: Addressing Challenges and Preparing for the Future, 12 June 2025. https://sonoma.courts.ca.gov/system/files/grand-jury/sonoma-county-airport.pdf — the claim that the airport supports approximately 1,700 jobs; the closure of Avelo's base on 1 May 2025.
• Avelo Airlines, opening of its Sonoma County crew base, May 2024. https://www.aveloair.com/company-news/avelo-airlines-opens-6th-aircraft-base-at-bay-area-sonoma-county-airport-doubling-number-of-nonstop-routes — 32 crew members hired, approximately 50 expected by year end.
• CBS News Bay Area, "Budget airline Avelo pulling out of Sonoma County Airport," 10 April 2025. https://www.cbsnews.com/sanfrancisco/news/budget-airline-avelo-pulling-out-sonoma-county-airport-ice-deportation-flights/ — Avelo's statement that the base closed due to low demand and because achieving the necessary financial results had proven more elusive than expected.
• KSRO, "Charles M. Schulz–Sonoma County Airport Looking To Fill Gaps Left By Avelo," 17 July 2025. https://www.ksro.com/2025/07/17/charles-m-schulz-sonoma-county-airport-looking-to-fill-gaps-left-by-avelo/ — Airport Manager Jon Stout on Avelo's departure from STS on 11 August 2025.

Tourism

• Sonoma County Tourism, research and visitor data. https://www.sonomacounty.com/partners/research/ — 10.5 million visitors and $2.4 billion in visitor spending in 2025.
• Visit Napa Valley, 2025 Visitor Profile and Economic Impact Study, released 28 July 2026. https://www.visitnapavalley.com/articles/post/visit-napa-valley-releases-2025-visitor-profile-and-economic-impact-data/ — 3.8 million visitors, $2.2 billion in visitor spending, $2.8 billion in total economic impact, 15,300 tourism-supported jobs. Visitor survey by SMARI Insights; economic impact by Tourism Economics. Public summary: https://assets.simpleviewinc.com/simpleview/image/upload/v1/clients/napavalley/VNV_Visitor_Ecomonic_Impact_Highlight_6139a43a-c271-44b5-9325-ed728bdb282e.pdf

Forecast against outcome

• Sonoma County Tourism, STS advertising media kit 2025. https://www.sonomacounty.com/wp-content/uploads/2023/09/STS_Advertising_Media_Kit_2025.pdf — projection of more than 850,000 passengers for 2025.

Economic impact and benefit-cost analysis

• Federal Aviation Administration, Airport Benefit-Cost Analysis Guidance. https://www.faa.gov/regulations_policies/policy_guidance/benefit_cost/FAA-Airport-Benefit-Cost-Guidance.pdf
• Office of Management and Budget, Circular A-94: Guidelines and Discount Rates for Benefit-Cost Analysis of Federal Programs, revised 9 November 2023. https://www.whitehouse.gov/wp-content/uploads/2023/11/CircularA-94.pdf
• US Department of Transportation, What is a benefit-cost analysis? https://www.transportation.gov/grants/dot-navigator/what-is-a-benefit-cost-analysis

Current county spending

• Sonoma County Board of Supervisors, 7 July 2026: air service development agreement with Crawford, Murphy & Tilly, task orders 1–11 at $373,006; Task Order 8 commissioning an IMPLAN economic impact report and materials to "highlight the impacts in presentations and on the Airport's website." https://sonoma-county.legistar.com/LegislationDetail.aspx?GUID=5D087FEB-91DB-4FC3-88C2-24BEDB6848D3&ID=8123218
• Sonoma County Board of Supervisors, 2 June 2026: Airport Revenue Strategy Update, projecting $1,467,912 in new annual fees from Southwest Airlines; across airline fees, ground leases, and other new or increased rents and fees, more than $2.5 million in new annual recurring airport revenue by the end of 2028. https://sonoma-county.legistar.com/LegislationDetail.aspx?GUID=F6A330F7-1FAA-4405-AC6C-39817C962CC5&ID=8035802

Regional employment

• US Bureau of Labor Statistics, Santa Rosa–Petaluma metropolitan area employment. https://www.bls.gov/eag/eag.ca_santarosa_msa.htm

Researched and drafted in collaboration with Claude (Anthropic).