Three separate surveys released this week show rising levels of anxiety among Americans over when -- or whether -- they'll be able to stop working.

On Tuesday, Ameriprise Financial (AMP) released a study that examined retirement readiness among people aged 40 to 75 in the nation's largest cities. Respondents were less confident about their ability to retire than they were last year. The financial services company also found increased reports of anxiety and depression surrounding retirement.

On Wednesday, several news outlets picked up the headline of Wells Fargo's (WFC) latest survey: 80 is the new 65. "The concept of 'a retirement age' is going the way of the typewriter," a press release proclaimed. That same day, a joint study produced by the Society of Actuaries, LIMRA and the International Foundation for Retirement Education reported that although confidence among retirees is returning to pre-crisis levels, significant gaps remain in understanding of what they're facing, and in planning for life after work.

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The Actuaries' study, titled The Financial Recovery for Retirees Continues,  is an attempt to measure the impact of the 2008 economic downturn on retirees' finances. The authors surveyed 461 retirees who had $100,000 or more in investable household assets in 2008, and who had participated in two previous surveys.

Many retirees grew more frugal in the downturn: 74% described themselves as more conservative and 46% had no debt in 2011, up from 38% in 2010. Possibly as a result of that, confidence is nearly back to pre-recession levels -- 85% of those surveyed this year say they are pretty sure they'll have enough money to live in retirement. In 2009, only 79% felt confident. In 2008, before the downturn really kicked in, the level was 88%.

But retirees aren't planning adequately, the study found. Many aren't taking into account that their retirement may last for 20 years. Only 45% of respondents believed that their retirement assets would need to last 20 years. In 2008, that number was 65%. "It's clear that retirees are hoping for the best or even taking an autopilot approach," wrote one of the study's authors.

The authors offer some suggestions for retirees. In a conference call with reporters, Betty Meredith, director of education and research at the International Foundation for Retirement Education, advocated new longevity insurance products that provide guaranteed income after a certain advanced age. She said that using those, as well as delaying Social Security and working a few more years, "could help a lot of boomers who are not prepared."

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