Two components comprise population growth: natural increase (births minus deaths) and net migration. Statewide, Delaware net migration accounted for 70% of the population change between 2010-19. In Sussex County, net migration accounted for 102% of the population change (deaths exceed births) compared to 67% in Kent County and only 12% in New Castle County.
Young people move into counties with good job opportunities while older folks migrate to counties with warmer weather, amenities (e.g., beaches, lakes), and lower taxes. Employment is not growing in New Castle County. The total regional population over age 55 is soaring and thinking about retirement.
Net migration includes both domestic migration (U.S. residents changing location) and international migration. Over 97% of the net migration into Sussex County from 2010-19 was domestic and 67% of the Kent County net migration. New Castle County had net domestic out-migration that was offset by net international in-migration.
What may be expected looking forward?
Sussex County’s net migration will slow as a growing population clogs the roads and the beaches. Regardless, the population growth in Sussex County will continue to add to consumption demand while doing little to boost economic productivity in Delaware. Burdened by strict environmental land use regulations and poor public schools, net domestic out-migration from New Castle County will continue.
Ultimately, below-average population growth will constrain future Delaware economic growth.