A study conducted by the California Policy Lab found that corrected estimates of migration patterns suggest signs of slowing pandemic-era trends in California. 

The study, released April 14, used credit bureau data from the UC Consumer Credit Panel ranging from the first quarter of 2016 to the fourth quarter of 2021 to conclude that the number of individuals leaving California to migrate to other U.S. states was decreasing, according to Evan White, a co-author of the study and the executive director of the California Policy Lab’s Berkeley site.

“The three Bay Area counties that saw the biggest pandemic changes to interstate exits and entrances – San Francisco, Santa Clara, and San Mateo – are all seeing returns to pre-pandemic patterns, though the spread between exits and entrances remains elevated in all three counties,” White said in an email.

The number of individuals entering California also rebounded, indicating a return to pre-pandemic migration patterns, White added.

The California Policy Lab also issued a corrected version of a migration publication from December 2021, according to a press release from the lab. 

Due to a methodological error, the previous publication had significantly underestimated the number of individuals entering California during the pandemic, White said in the email. This error, however, had no impact on the estimates of individuals leaving California. The correction indicates that quarterly migration into California was 8% lower in the third quarter of 2021 than in the first quarter of 2020. The previous publication mistakenly indicated that this value was 38% lower. 

While credit bureau data is generally a reliable measure of mobility, it has its shortcomings. Because the migration data only sampled adults with credit histories, the subjects involved in the study have characteristics that may not fully represent the overall population, White said in the email. Children are also not included in the sample, he added.

“Because the sample consists of adults with credit histories, it is slightly older, more financially advantaged, and less racially and ethnically diverse than the overall adult population,” White said in the email. “As such, these results are less able to capture patterns of residential mobility among lower-income Californians and among racial and ethnic minorities.”

With this data, scientists are able to determine the effects of a fluctuating Californian population. Demographic changes have the power to affect federal funding formulas and reduce the state’s political power. A potential result of this could be California losing a congressional seat. 

News reports and other sources have speculated whether there has been a mass exodus from California throughout the pandemic, White said in the email. The lab’s research may alleviate these debates and questions regarding population changes in California, he noted. 

“We wanted to help inform this important debate through our research, and credit-bureau data is one of the best sources to do that,” White said in the email.