Economics correspondent Paul Solman explores the question of just how high U.S. tax rates should or shouldn't be and examines the relationship between economic activity and tax rates. It's part of his ongoing reporting series, Making Sen$e of financial news.

A jobs sign hangs above the entrance to the U.S. Chamber of Commerce building in Washington, D.C. Photo by Karen Bleier/AFP/Getty Images. Friday's unemployment figures are positive all around: The official unemployment number dipped to 8.5 percent, a rate…