Newsom’s Big Housing Claim Is Built On Bad Data

In June, Gavin Newsom sat on a stage in Long Beach before an audience of mayors from across the country and unveiled a stunning statistic.

“We’ve seen a 59 percent increase in the number of homes constructed” during his tenure, the California governor said to applause.

The number quickly came to symbolize the remarkable progress Newsom claims to have made on an issue central to his agenda and to Californians struggling to afford housing. His administration has touted the statistic in at least five news releases, including one last week.

But a POLITICO analysis found Newsom’s tally was based on badly incomplete data that did not include homebuilding figures from San Diego and other large jurisdictions. The flawed methodology led the governor to significantly inflate the rate of construction — by more than three times, according to one established benchmark, POLITICO determined.

“It’s a pretty basic error,” said Michael Lens, an urban planning professor at UCLA and director of the school’s Lewis Center for Regional Policy Studies, who reviewed POLITICO’s findings.

The statistic carries weight for Newsom as he seeks to define his gubernatorial legacy and burnish potential weak spots on his resume ahead of a likely presidential bid. While the high cost of housing continues to plague California, a jump in production would demonstrate a meaningful advance on an intractable problem, and one that could offer a salve for the breaking of a lofty campaign promise.

Instead, none of the metrics typically used to measure production show homebuilding in California grew anywhere near the level the governor claims to have reached. For instance, data from real estate firm Cotality shows home completions increased by 18 percent from 2018 the year before Newsom took office, to 2024, which the governor used in comparison. Home permitting data collected by the U.S. Census Bureau, another common measurement, indicates production actually declined between 2018 and more recent years.

The governor based his calculation on annual progress reports that cities and counties submit to the state on the number of homes completed in their jurisdiction. These data showed 70,000 homes completed in 2018 compared to 111,000 in 2024, reflecting the 59 percent increase the governor claimed.

But in 2018, more than a quarter of California’s 539 local governments either failed to provide statistics or reported no homes were built. San Diego was among the cities to tell the state no homes were constructed that year. But more than 25,000 homes were permitted in the city in the five years beforehand, indicating that completions in 2018 likely measured in the thousands.

The cities of Stockton and San Bernardino and unincorporated Orange County were among other large jurisdictions that didn’t provide statistics or claimed zero finished homes in 2018.

In 2024, data collection improved substantially with 69 more local governments reporting housing completions, including San Diego and other population centers missing from 2018. As a result, the governor’s claim reflects this increase in responses more than a measurement of California’s housing production.

In a response to questions from POLITICO, the governor’s office defended Newsom’s calculation and did not address how the missing data skewed his claim of a surge in building.

“Calculating housing completions using the data as reported by cities and counties shows an increase of 59 percent during this administration,” Newsom spokesperson Tara Gallegos said. “The governor’s strategies to help address the housing crisis are working, creating foundational changes that will continue to increase housing for generations.”

High housing production numbers are of particular importance to Newsom because of promises made during his 2018 gubernatorial campaign. He pledged to build 3.5 million homes during his time in office, or 500,000 a year. Newsom argued that level of supply was necessary to address a shortage driving up costs.

“It’s what must be done,” Newsom told the Los Angeles Times in early 2018.

At the time, experts panned Newsom’s guarantee as fanciful, noting that his numbers were far above what California produced even during its mid-20th century boom. As construction inevitably has fallen short of the governor’s promise, he has said his campaign pledge was always meant as a “stretch goal.”

Multiple statistical sources show that homebuilding in California has increased during Newsom’s tenure compared to his predecessor Jerry Brown, who served when construction reached historic lows in the aftermath of the Great Recession. But growth has leveled off, with production largely hovering between 100,000 and 120,000 units annually.

For what seems like something simple, measuring housing production is notoriously fuzzy. Different sources track different metrics, such as the number of housing permits issued versus houses completed, and all come with varying levels of quality control, Lens said.

“We’re finding this is a very hard thing to capture,” said Lens, who is part of a national consortium of scholars seeking to standardize housing production data for major metropolitan areas.

Further complicating the situation is the cyclical nature of homebuilding, which is driven by demand, interest rates, material and labor costs and many other issues outside the control of a governor. Production can swing from one year to the next, making it hard to decipher broad trends of increased or decreased building.

For instance, the 18 percent increase in housing completions the Cotality data shows when comparing 2018 and 2024 totals, drops to 8 percent if 2025 figures are used instead.

At first glance, one metric does appear to support Newsom’s claim. The state Department of Finance measures the change in the number of housing units in California each year. Its data shows a 53 percent increase between the net number of new homes in 2024 versus 2018. But to use those numbers as proof that building boomed would be misleading because some of the most destructive wildfires in California’s history occurred in 2018. When the 16,300 homes lost in the three worst fires that year are taken into account, the Department of Finance data would reflect only a 28 percent increase between 2018 and 2024, a year when there were no comparable fires.

Katie Talbot, a spokesperson for the California Housing and Homelessness Agency, acknowledged gaps in the state’s home completion data. But she contended it is the best way to measure housing production because the figure was most relevant to Californians.

“People care about homes being built,” Talbot said. “Housing completions are a valid and important statistic to help showcase the genuine, on-the-ground progress the state is making on the affordable housing crisis.”

Lens said there’s nothing to suggest that the governor’s efforts have been material in increasing homebuilding above recent norms. That’s despite Newsom supporting many laws that he believes ultimately should boost growth, including last year’s bids to exempt urban housing developments from the California Environmental Quality Act and increase density around mass transit.

“There’s no doubt to me that there’s been a tremendous amount of progress in terms of policy changes,” Lens said. “The harder win, and a win that is currently elusive, is evidence that these policy changes are having a dramatic impact on the pace of housing production.”