HERE'S an early Christmas present for the economists of Wall Street.
2015 may be the first year in five in which they get to raise forecasts for global economic growth rather than cut them.
That may be fanciful thinking as the year ends with Russia in crisis, investors rediscovering volatility and central banks returning to the monetary pumps. Other potential risks include more geopolitical flare-ups, elections from Greece to the UK, a hard landing in China, a premature exit from Federal Reserve stimulus and a slide toward deflation in Europe and Japan.
Recent history is on the side of the pessimists. A year ago, the median forecast of economists surveyed by Bloomberg News was for growth of...