Google's chief economist is (as in June 2009) Hal Varian, a lanky (says Steven Levy, in Wired Magazine), 62-year-old professor at UC Berkeley's Haas School of Business and School of Information, Google's chief economist.
CGO is the fun and most pertinent acronym coined in a split second by Susan Noonan, former McKinsey communication specialist, when I introduced her to Mr. Varian and his googlenomics.