Why are the values and growth rates for U.S. (sum-of-states) GDP by state not equal to the values and growth rates for GDP in the national accounts?

Federal civilian and military personnel stationed abroad are included in the measure of GDP in the national accounts but excluded from GDP by state because they cannot be assigned to a particular state. More specifically, GDP by state excludes the wages and salaries and wage and salary supplements of these personnel. Also excluded are the capital consumption allowances associated with Federal government structures and equipment located abroad, and all military weaponry. In addition, some of the difference may be due to GDP by state and GDP in the national accounts having different revision schedules.