President Barack Obama sure has been talking about Warren Buffett's taxes a lot lately. At his speech before a joint session of Congress this month, the president said that the billionaire shouldn't pay a higher tax rate than his secretary, a point Buffett has often made. The secretary's tax rate, and her boss's, made another appearance on Sept. 19 in Obama's address on his deficit-reduction plan.

When the president invokes Buffett's name, he is using it to enhance his own economic credibility. It's an old habit for him. On the campaign trail in 2008, when Obama wanted to talk about the unjustness of the tax code, he often turned to Buffett — sometimes referring to him as "my friend Warren Buffett." For his part, Buffett appears pleased to play along; he'll headline an Obama fundraiser in Chicago next month.

But why should the president stop at using Buffett's name as shorthand for tax reform? The entirety of Buffett's life and career offers lessons that could guide Obama as he works to steer the U.S. economy toward recovery.