When you hear Americans described as a uniquely mobile people, you may envision them pulling up stakes and striking out for distant frontiers. The facts are more prosaic. A new report from the Census Bureau confirms that Americans move in droves, but also notes that the majority of them don't move very far. Analyzing data from March 1999 to March 2000, the study found 43 million U.S. residents (16 percent of the population) moved to a new home. But 56 percent of moves were within the same county, and another 20 percent were from one county to another in the same state. Just 19 percent were from one state to another. As you'd expect, moves were much more common among renters than homeowners (33 percent vs. 9 percent). That's consistent with a breakdown of the statistics by income. Among households making under $25,000, 21 percent moved; among those making more than $100,000, 12 percent did so. What moved people to move? About half did so for what the Census Bureau classifies as "housing-related reasons." Most common of these was a wish for new or better quarters (18.5 percent), followed by a desire to own rather than rent (11.5 percent). A mere 5.5 percent moved to get cheaper housing. Of the report's other categories, "family-related" factors accounted for 26.3 percent of moves. Those moving to "establish own household" (7.4 percent) outnumbered those relocating due to a change in marital status (6.2 percent). Surprisingly few Americans moved for "work-related reasons" (16.2 percent), including the 9.7 percent who relocated to accept a new job or a job transfer. While the category of economic relocation may bring to mind images of dust-covered Okies, the report offers a corrective: "The unemployed are not more likely than the employed to move for work-related reasons." Indeed, relocations for work-related reasons were more common among households making $75,000-plus than any other income cohort.