Portland State researchers stand by finding that Oregon’s population grew in 2023

Published 9:00 am Sunday, December 31, 2023

PORTLAND — Population researchers at Portland State University stand by their finding that Oregon’s population grew last year, despite an estimate from the U.S. Census Bureau that suggests the opposite.

The Census Bureau’s 2023 population estimates, released in mid-December, showed that Oregon lost about 6,000 residents in the year leading up to July 1, 2023, representing a 0.1% loss to a total of 4,233,358 residents. That came after the state shed about 0.4% of its residents in the year before.

But recently revised certified estimates by Portland State University’s Population Research Center show that Oregon’s population grew by a tepid 0.52%, or roughly 22,000 residents, over the same time period. The center estimates that the state’s population now stands at 4,291,525.

Both sets of estimates are used by policymakers, including to allocate funding for state and federal programs. Political representation and districts, though, are based on the person-by-person census conducted every 10 years, not the estimates produced in between.

The Population Research Center’s numbers don’t always exactly match those developed by the Census Bureau because each organization uses different methodologies and data sources, said Huda Alkitkat, a population estimates program manager at Portland State.

“Over the last years, there have always been differences in the estimates … because of the assumptions and data used for the two models,” she said. “Recently, the difference is clear because the (U.S. Census Bureau’s) estimate shows a decline in the population, and the PRC’s estimate still shows an increase.”

The two estimates differ the most in their measure of migration to and from the state, Alkitkat said. And because of Oregon’s low birth rates and aging population, migration has an outsized influence on the state’s overall population trend.

While the Census Bureau estimates are based in part on mailing addresses on IRS tax returns, Portland State researchers don’t have access to those records until months later. But both use data from the 2020 national census, birth and death certificates, driver’s licenses applied for or surrendered, and other indicators of population change.

Meanwhile, Portland State also incorporates employment, school enrollment and housing market data to estimate population changes.

The Portland researchers say the Census Bureau may now be catching up to pandemic-era trends spotted locally a year earlier.

Alkitkat said Portland State’s estimates showed Oregon’s population decreased between July 2020 and July 2021, whereas census data showed an increase during this time. Then, over the next two years, the Portland State center’s estimates showed a population increase while the Census Bureau showed declines.

Ethan Sharygin, director of the Population Research Center at Portland State, said both organizations captured a year of significant population declines— the center saw it between July 2020 and July 2021, while the census saw it the next year. He said Portland State saw a larger population rebound between July 2021 and July 2022, gleaned largely from out-of-state IDs surrendered to the Oregon DMV.

The Population Research Center’s estimates show that more Oregonians died than were born in the year leading up to July 2023. But that was “offset by a net migration of approximately 21,000 new residents to the state,” Alkitkat said, based on the center’s analysis of data from the Oregon Department of Transportation, the Census Bureau and U.S. Customs and Border Protection.

Without migration, Portland State researchers said Oregon’s population would be in decline. The center found that 29 counties in the state saw more deaths than births in the past year. But only six counties in the state experienced population decline over the same time period, thanks to a net migration of new residents.

Because of those trends, economists say Oregon depends on working-age people moving from elsewhere to shop, pay taxes and join the workforce. Slower population growth, or a population decline, would strain Oregon’s economy, leaving companies struggling to hire workers or grow their sales.

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