The U.S. may face a prolonged period of stagnation. That's the warning from a Reuters op-ed written earlier this week by PIMCO CEO and co-CIO Mohamed El-Erian. He worries that the U.S. could be on a worse path than Japan was when it began its "lost decade." But he ends with a note of optimism, saying that policymakers have the power to avoid Japan's fate. Both their willingness and ability to do so should worry us, however. Why We Face a Lost Decade What has gone so wrong that the U.S. could be in for a decade or more of...