Components of Population Change

Data Table

Explanation

Population growth is driven by two factors: 

  • Net migration: people moving in minus people moving out
  • Natural increases: births minus deaths

Since 1960, most population growth in Thurston County has been due to migration. Net migration is strongly influenced by economic conditions. When unemployment is high, net migration tends to be low. People also move to Thurston County to commute to jobs in nearby counties, where housing costs tend to be higher. Since 1960, there has only been one year where out-migration was greater than in-migration (1968-1969).

Population change due to natural increase tends to be more stable. 2021-2023 were the only two years on record where deaths in Thurston County outnumbered births.

Natural Increase

The natural increase in population is the number of births minus the number of deaths in a calendar year.

Net Migration

Net migration is equal to the number of people moving to Thurston County minus the number of people moving out of Thurston County.

Source

  • Washington State Office of Financial Management