Which city has a higher percentage of residents with a college education: Boulder or Boston? If you guessed Boston – a city strongly associated with some of the country’s most prestigious higher education institutions – well, you’d be wrong.

According to 2007 data from the Census Bureau’s American FactFinder, Boulder, Ithaca, and Ann Arbor, three large “college towns,” ranked among the top three metro areas with the highest percentage of population aged 25 and older having completed a bachelor’s degree or higher education.

On a regional basis, the largest percentage of the adult population with a bachelor’s degree or higher live in the Northeast, according to Educational Attainment in the United States: 2007, recently released by the U.S. Census Bureau. Information in the report was based on two data sources: American Community Survey (ACS) and the Current Population Survey (CPS).

The District of Columbia carried the highest concentration of college graduates, with 47 percent of its adult residents having earned a bachelor’s degree or higher. In addition to D.C., more than one in three adults had at least a bachelor’s degree in Colorado, Connecticut, Maryland, Massachusetts, and New Jersey.

On the flip side, the smallest percentage of the population with a college education was in the South, according to the survey. Less than one in five adults had a bachelor’s degree or more education in Arkansas, Mississippi and West Virginia.

Higher educational attainment is associated with higher earnings on average … Median earnings for a worker with a bachelor’s degree were 74 percent higher than median earnings for a worker with a high school diploma alone, and median earnings for an advanced degree were 31 percent higher than earnings for a bachelor’s degree, according to the Census Bureau.