Portfolio.com and bizjournals set out to find the medium-sized markets that offer the best quality of life. Here are the details:

Criteria: The study looked for well-rounded areas with healthy economies, light traffic, moderate costs of living, impressive housing stocks and strong educational systems.

Areas: Portfolio.com and bizjournals analyzed all 109 metropolitan areas that had populations between 250,000 and 750,000 as of 2008. Statistics cited in the study encompass all portions of metros, not just their central cities.

Sources: Raw statistics came from the U.S. Census Bureau’s 2006-2008 American Community Survey, which was released late last year. All percentages, ratios and growth rates were calculated by Portfolio.com and bizjournals.

Factors: Portfolio.com and bizjournals used a 20-part formula to rate each market’s quality of life. Each component is followed in parentheses by the trait it measured and the type of reading—highest or lowest—that earned a maximum score:

1. Population growth since 2000 (growth, highest).
2. Percentage of residents who have lived in the same home for more than one year (stability, highest).
3. Share of all residents who are between the ages of 25 and 44 (young adults, highest).
4. Percentage of workers who work at home or walk to work (ease of movement, highest).
5. Average commuting time to work (ease of movement, lowest).
6. Median household income (earnings, highest).
7. Poverty rate for families (earnings, lowest).
8. Mortgage affordability, calculated as a ratio of median house value per $1,000 of median household income (cost of living, lowest).
9. Rent affordability, calculated as a ratio of annual median rent per $1,000 of median household income (cost of living, lowest).
10. Unemployment rate for persons between the ages of 25 and 64 (employment, lowest).
11. Percentage of all jobs that are classified as management or professional positions (employment, highest).
12. Percentage of workers who are self-employed (entrepreneurship, highest).
13. Percentage of houses that have been built since 1990 (housing stock, highest).
14. Percentage of houses that have nine or more rooms (housing stock, highest).
15. Housing vacancy rate (housing stock, lowest).
16. Homeownership rate (homeownership, highest).
17. Median house value (homeownership, highest).
18. Percentage of adults (25 or older) who hold high school diplomas (education, highest).
19. Percentage of adults (25 or older) who hold bachelor’s degrees (education, highest).
20. Percentage of adults (25 or older) who hold advanced (master’s, doctoral and/or professional) degrees (education, highest).

Formula: Each market’s statistics were compared against the averages for the study group in all 20 categories.

Above-average performances received positive scores, while below-average results received negative scores. Each area’s 20 category scores were totaled to determine its overall rank. Final scores ranged from 21.059 points for Boulder, Colorado, to minus-14.635 points for Visalia, California.