Super-low interest rates haven't done what they usually do after a recession. They haven't ignited economic growth or revived the home market or persuaded consumers to spend freely again. They have, though, caused misery for retirees and others who depend on interest income. Such income plummeted 27 percent from 2008 to last year. Now, some economists worry that low rates might be hurting the economy itself -- defeating the purpose of the Federal Reserve's low-rate policies. When savers earn less, they spend less. And spending by individuals drives about 70 percent of the U.S. economy. Those concerns arise 2 1/2...