Masaaki Shirakawa (left), Jean-Claude Trichet and Ben Bernanke at Jackson Hole, Wyoming

As central bankers from around the world queued on the terrace of Jackson Lake Lodge at the weekend to gaze at the stars above the Teton mountains through almost Nasa-sized telescopes, they must have wished they had as much clarity on the economic horizons they usually scan as they did on the constellations above.