To feel good again, the world’s financial elite need a growth catalyst like the Internet. America’s shale gas revolution fits the bill. Ask delegates at the World Economic Forum (WEF) in Davos for their 2013 outlook, and that simple idea features in most answers. It may only surface as a passing reference in conversations around the Swiss ski resort. But in the echo chamber of Davos, the notion that shale gas is a reason to be bullish has become common wisdom.