Every week, one financial services firm or another releases findings of its latest retirement study: Americans aren’t saving enough. The savings rate is abysmal. Americans keep up with the Joneses at the expense of their Golden Years. They borrow against their homes to pay for luxuries, and so forth. But is the situation as dire as most people think? A New York Times story on January 27 cited a handful of academics who think Americans are saving plenty — too much, in many cases. So who is right? There is no definitive answer, says Olivia S. Mitchell , professor of insurance and risk management at Wharton and executive director of the school’s Pension Research Council. Some studies, including one of her own, suggest Americans are not headed for the old-age catastrophe that many predict. But key factors, like the future health of Social Security, are impossible to handicap. “It’s just a brutally difficult problem,” she notes.…