I just bought my airline ticket for my friend's 100th birthday party, which she's anticipating with considerable excitement. Life has been quiet since she gave up competitive ballroom dancing at 85. Planning a party spices things up.

The oil wells that my friend's husband left her have kept her lifestyle comfortable – until the last couple of years when she developed a need for 24-hour care after the car she was riding in was broadsided.

Even a couple of active oil wells don't gush enough money to cover all the expenses of extreme aging. My friend and her children, who are old enough to be contemplating their own retirements, can see the day when it is all going to run out. If mom's still around – and the doc says she very well could be – longevity is going to be an expensive problem.

Retirement isn't what it used to be, particularly for those of us contemplating it without oil wells or pensions or big 401(k) savings accounts.

A history of retirement by Joanna Short, associate professor of economics at Augustana College in Illinois, points out that one of the most significant changes in the American labor market over the course of the 20th century was the virtual disappearance of older men from the labor force.

In 1880, 76.7% of white men and 87.3% of black men were what the U.S. Census called, "gainfully employed." By 2000, 17.8% of white men and 16.6% of black men met the gainfully employed standard. (These figures don't include women because until World War II, very few of them worked outside of the home.)

Short concludes that a combination of factors made it possible for so many men to enjoy a leisurely retirement, including better healthcare, company pensions, Social Security and tax-advantaged savings accounts like 401(k)s.

Today, everything seems shaky. Even good health is threatened by the rising cost of healthcare. My husband and I used to laugh that if all else failed, we were going to buy a doublewide overlooking the Pennsylvania Turnpike where we could always get a cheap meal at the truck stop and hitch a ride on an 18-wheeler. That seemed like a joke, but these days, considering our hard-hit retirement accounts, it may be one of our better options.

Of course, being baby boomers, we've never done anything that we didn't do in a crowd and retiring without much money – or working until we drop – is going to be one more experience that we share with millions.

The U.S. division of Sun Life Financial Inc. last month released the latest edition of its Unretirement Index, which reveals 65% of American workers will delay their retirement by at least one year – an 11% increase since the end of 2008. The Index also indicates 27% of Americans now believe they will need to work at least five years longer than expected because of the current economic environment.

More than 55% of those surveyed say they will work full- or part-time at 67, and another new high of 28% of US workers across all age groups are planning to work full time past the age of 67.

Only 28% of working Americans are confident that they will have sufficient retirement resources. In addition, only 22% are very confident that they will be able to take care of medical expenses and only 40% are very confident that they will have enough money for basic living expenses in retirement. Overall, fewer than 25% of workers are confident they will be able to live the kind of life they want in retirement.

Meanwhile, I've been trying to decide what to buy my friend for her 100th. Given the state of things, maybe I should be letting her do the buying. After all, I don't have any oil wells.