In Geographical Mobility: 2007, the bureau reports that 38.7 million people moved during that period. In that group, 25.2 remained in the same county, 7.4 million changed counties but not states, 4.9 million moved to a different state and 1.2 million moved to the United States from other countries.

Among those who moved to another county, 42 percent stayed within 50 miles of their previous home, while 22 percent moved 500 miles or more. In metropolitan areas, urban areas had a net loss of 1.9 million while suburbs had a net gain of 2 million.

The Northeast was the most stable area with only 9 percent of residents moving. In the Midwest, 13 percent moved, while 14 percent moved in the South and 15 percent in the West.

The largest group, 42 percent, said they moved to buy a house, to live in a better neighborhood or another housing-related reason. Thirty percent said they moved for family reasons, and 21 percent for a job.