Ada County in 2020: Out-migration surpassed in-migration within Idaho

IRS data show urban outflows to exurban counties

In 2020 Ada County posted a net migration loss within Idaho. Simply stated, more Idaho residents moved out than moved in.

Inbound migration to the state’s most populous county from other parts of Idaho totaled 8,039, while outbound migrants numbered 10,610 for a net migration loss of 2,571. Where did they go?

 Figure 1: Ada County largest net migration losses, 2020

Source: IRS data accessed through, Feb. 14, 2023

With the exception of outflows to Idaho County, the largest number of Ada County residents migrated to counties within the commute shed – an area within a 30-minute commute – with 1,874 leaving for neighboring Canyon County.

Of course, the economic conditions of 2020 differed greatly from today. That was the height of the pandemic and large numbers of workers either exited the workforce, had the ability to work from home or a combination of both. The numbers seem to reflect that, as most of the relocations were within commuting distance, supporting the ability to work remotely but also access the office on occasion. The 2020 housing market was also at its peak, likely leading to homebuyers seeking more affordable locations than Ada County.

The data on positive inflows to Ada County from other parts of Idaho reveal some interesting findings. For example, Ada County had positive inbound migrations from only 12 counties totaling just 242 people.

Twin Falls County, which was designated part of a metro area in 2018, was the only urban area to feed into Ada County and represented the largest number of new residents, albeit very few,

Except for Twin Falls, the remaining new residents came from rural counties. Their movement to Idaho’s economic hub represents what economists call “exporting unemployment.” This refers to the phenomenon of people leaving areas with few job prospects for areas with more employment opportunities.

Figure 2: Inbound migration to Ada County, 2020

Figure 2: Inbound migration to Ada County, 2020

Source: IRS data accessed through Feb. 14, 2023

While that was happening within Idaho, what about new residents from outside of Idaho? To answer one popular question on many peoples’ mind is this: are the Californians continuing to come? In a word, yes.

Except for King County, Washington — the greater Seattle area — the nine counties in the U.S. with the most residents moving to Ada County in 2020 arrived from California. The majority of the inflows were from Southern California – Los Angeles, Orange County, San Diego and Riverside counties. Northern California was also well represented with Santa Clara, Contra Costa and Alameda — the Bay Area or Silicon Valley — counties sending large numbers to Ada County.

Likely reasons for these inflows? It could be the relatively lower cost of living in Ada County and easy access to Idaho. All four of the southern California counites have airports within a 90-minute flight to Boise.

Figure 3: Top 10 counties sending resident to Ada County, 2020

Figure 3: Top ten counties sending resident to Ada County, 2020

Source: IRS data accessed through Feb. 14, 2023

Real estate prices and the pandemic-induced changes to the labor market most likely explain migration patterns in 2020. With the macro economy exhibiting very different conditions in 2022-2023 — low unemployment, higher inflation and rising interest rates — the next time we review this data a very different story could emerge., research analyst, principal
Idaho Department of Labor
208-332-3570 ext. 3690