The city has the 46th strongest economy in the U.S., compared to a 39th place ranking in 2009. Memphis’ ranking has steadily declined since 2006, when it ranked 12th in Policom’s survey.

The top 10 are Seattle; Washington, D.C.-Arlington-Alexandria; Denver; Houston; Sacramento, Calif.; Salt Lake City; Des Moines, Iowa; San Diego; Madison, Wis.; and Dallas-Fort Worth-Arlington.

The study focused on 366 metropolitan areas. Policom considers a metropolitan area to be at least one urbanized geographic location that has a population of 50,000 or more people.

To determine how these areas are performing, Policom measures 23 different economic factors.

The data company followed 20 years of data covering 23 economic factors to create the rankings. The most recent study focused on a 19-year period stretching from 1989 to 2008.

"The top rated areas have had rapid, consistent growth in both size and quality for an extended period of time," said William Fruth, president of Palm City, Fla.-based Policom. “The rankings do not reflect the latest ‘hot spot’ or boom town, but the areas which have the best economic foundation. While most communities have slowed or declined during this recession, the strongest areas have been able to weather the storm.”

Policom is an independent research firm that focuses on economics and specializes in analyzing local and state economies.