Of the 1,600 Americans who reach retirement age each day, 77 percent have done no comprehensive retirement planning.

"We put more planning into a two-week vacation," said David Gamse, director of the American Association of Retired Persons worker equity department.Social Security benefits make up the largest portion of most American retirees' income, followed by pensions. But variables like early retirement and decreasing ratios of workers to those receiving benefits are creating interesting problems for those contemplating retirement.

Nearly four workers contribute to the Social Security fund for each person receiving benefits, but that number is shrinking - and will shrink drastically when baby boomers begin to retire. By 2030, experts say two workers will support each recipient.

"In 1950," Gamse said, "46 percent of older men were working. In 1987, only 16 percent work."

A federally sponsored survey found that of those within five years of normal retirement, and participating in their company's pension plan, 73 percent did not know when they could retire, according to Roger Thomas, attorney and former general counsel to the House Select Committee on Aging. Of workers over 50, 68 percent had no immediate plans to retire. But given an exit incentive, most said they would choose early retirement.

"People can afford retirement more," said Dallas Salisbury, president of the Employee Benefits Research Institute. "Companies have even found themselves shorthanded because three or four times as many accept the (early retirement) option as projected.

"As long as Social Security is available, we'll see more retiring. If they moved Medicare to 67, we'd see more stay in the work force. There's a heavy dose of schizophrenia in that we provide economic incentives for people to retire and wonder why people choose to retire."

Two-thirds of retirees choose to take their pension settlement in a lump sum, rather than annuities, a practice some later regret, Salisbury said.

"People believe they'll die about 10 years sooner than they do, statistically," he said. "So they think the money will stretch out and it won't. It's a natural tendency to try to spend all the money while you're alive,but if you live longer than expected and there's no money . . . "

The employment picture for older citizens is changing, too.

"Age discrimination charges are rising," Gamse said."The kinds of jobs older people have long held are disappearing and the short-range view is pretty bleak, but in the long range, there will be lots of jobs because there won't be enough young workers."

Another relatively new phenomena, according to Thomas, is termination of overfunded pension plans by employers. "Before '80, we basically didn't see termination to recover so-called `surplus' assets. Now (employers) can create a fictional termination of a plan, take the assets and reimplement. More than $19 billionhas been returned to employers through terminations.

"Retirement plans are voluntary. There's no requirement that a company start or maintain a plan. And this trend is perhaps one of the most erosive."

Even when the employer "plays fair," Thomas said people hurt themselves because they don't realize the implication of not saving today. "The longer you wait, the harder you have to work at it."