Oregon's record-breaking population growth slowed slightly in 2018, but will still be the third-highest increase in state history, according to preliminary estimates from the Population Research Center at Portland State University.
The state's population as of July 1 was estimated to have increased by 54,200 people to 4,195,300 since the same time in 2017, according to estimates released Nov. 19. That is an increase of 1.3 percent, only slightly less than the 1.6 percent increase in 2016 and 2017.
According to the estimates, 2018 will be the third year in a row that the state's population has increased by more than 50,000 people; 88 percent of the additional people came from out of state this year.
"The last couple years were real outliers. The 2018 increase is still a large increase. It's extreme growth by historical standards," Charles Rynerson, a research faculty member at the center in PSU's College of Urban and Public Affairs, said.
The slowdown reflects weakening growth across the entire country. The population of the United States grew at its slowest rate in eight decades — 0.06 percent — according to Census Bureau figures released in mid-December. Oregon's growth is still strong enough to probably guarantee it will gain a U.S. House seat during scheduled congressional redistricting in 2021, however.
Much of the state's increase is continuing to happen in the greater Portland area. Multnomah and Washington counties each added more than 10,000 residents, while Clackamas County added more than 6,000.
Portland is expected to add more residents than other cities in Oregon in 2018, growing by 9,640 people to a total of 648,740. That is an increase of 1.5 percent.
The populations of Beaverton and Tigard are both expected to increase by more than 1,000 people. Happy Valley, in Clackamas County, had the fastest growth rate, at 4.8 percent. The second-fastest growing city is Bend, which is expected to add 2,740 residents — a 3.2 percent increase.
According to Rynerson, the slight slowdown from 2017 is caused by decreases in both "natural" and "net migration" growth.
Natural growth results from the number of births minus the number of deaths of the existing population. Rynerson said Oregon's birth rate is at a record low. At the same time, the state's population is aging, resulting in more deaths.
Net migration is the difference between the number of people moving into the state minus the number moving out. The number moving into Oregon slowed last year, although it still exceeded the number moving out. Rynerson said the number of people moving into the state probably slowed because there are fewer available jobs while the cost of living is increasing, especially housing costs.
According to Rynerson, one-quarter of the people moving to Oregon are expected to come from California in 2018.