The county of Los Angeles's population declined over the past year, even as other major counties of the state added residents.
"There are large urban core districts across the country that either lose their population or gain less than they did three or four years ago," said William Frey, a demographer at the Brookings Institution. He said it was a reversal from earlier in the decade of 2010, when cities and metropolitan areas grew faster than suburbs.
According to data from the census, slightly more than 26% of the 360 metro areas in the US in 2018 recorded a population decline. The regions with the largest decline were mainly due to negative net internal migration.
Although Los Angeles County lost residents, the new census data show that California added 157,696 residents nationwide in 2018, reaching a population of 39.557 million.
The county of San Diego, the second largest district of California with 3.34 million inhabitants, increased in 2018 according to new census data almost 17,896 people. In addition, the districts of San Francisco Bay grew slightly in 2018, including Alameda (8,622 new residents), Contra Costa (5,352) and San Francisco (4,139).
In Los Angeles and other major cities in California, populations rose in the 1980s, in part due to international immigration from Latin America and Asia. Although this growth has slowed down significantly until 2000, newcomers have only increased the pressure on the tense real estate market in the last five years.
The housing situation in Southern California is particularly harsh for low-income residents. California has approximately 7.5 million people living in poverty, including about 15% of the Los Angeles County population.
USC's Green said there was an overflow of residents from Los Angeles who moved to nearby Inland Empire counties such as Riverside and San Bernardino. "They have all these people competing for housing and there just is not enough of that," said Green.
Census data shows that the Inland Empire region added more than 50,000 in 2018.
According to Rentcafe, average rents in Los Angeles County are $ 2,371 per month, an increase of 7% over the previous year. By comparison, San Bernardino County has average rentals of $ 1,229 and Riverside County of $ 1,528.
In addition, the Riverside and San Bernardino counties have become distribution centers and sites for large fulfillment centers operated by Amazon and other companies. They have created thousands of new jobs in the domestic empire area over the last decade and strengthened the housing estate.
"We've seen more jobs being moved east to the Riverside and San Bernardino counties," said Green. "They are becoming increasingly important centers of the regional economy."
– Artwork by John Schön of CNBC.