Jim McTague devotes his latest Barron’s “D.C. Current” column to documenting the details of the Greased Palm Index, “which reflects political donations by Corporate America and has maintained a small lead over the S&P 500 this year, rising 8.1%, through Monday, to the benchmark’s 7.5%.”

Unlike the S&P 500, membership in the GPI is as flexible as Tarzan’s pet chimp Cheetah. In 2004, it contained 45 listings. The list shrank this year because employees at fewer companies made meaningful donations, presumably because the sick economy has reduced disposable income.

There’s a baldly cynical notion behind the GPI: Corporate donations purchase political goodwill, an asset that you won’t find listed in any 10-K. And in an age where extreme government meddling in our markets is the norm, every bit of political goodwill helps.