Does it pay to be one of the companies featured in Fortune magazine’s annual list of the 100 Best Companies To Work For in America? According to Alex Edmans, finance professor at the University of Pennsylvania, the answer is a definite “YES.” Professor Edmans found that the stock returns of companies cited as good places to work were more than double those of the overall market. Specifically, companies on Fortune’s list between 1998 and 2005 returned 14 percent per year, compared to 6 percent a year for the overall market.

The top 10 companies on Fortune’s 2008 list of the Best Companies to Work For are:

1. Google
2. Quicken Loans
3. Wegmans Food Markets
4. Edward Jones
5. Genetech
6. Cisco Systems
7. Starbucks
8. Qualcomm
9. Goldman Sachs
10. Methodist Hospital Systems

The lesson here? Companies that are able to attract and keep great employees are better able to serve customers and create value for stockholders.