The Great Moderation was a name economists gave to a post-1982 era marked by only two mild recessions and long stretches of uninterrupted growth. That's over, and the transition to whatever comes next will, if history is any guide, be messy. From 1970 to '82, the U.S. economy was hit by four downturns, two of which (1973-75 and 1981-82) until recently competed for the title of "worst since the Great Depression." The current recession has undisputed claim to that title. And while we may be about to climb out of it, don't be surprised if we endure more downturns. Think of a W shape — maybe multiple Ws — not a V.