In California last week, the four remaining candidates for the Democratic nomination for president appeared together for a televised question-and-answer session. Answering questions from two journalists and Larry King, the candidate offered their positions on various topics. The object was to avoid controversy and appeal to as many voters as possible. If elected, they would stop job losses to foreign countries, increase spending for education, implement universal health care, and ensure that Social Security and Medicare - and balance the budget, without raising taxes except on the wealthy

It sounded good, if unrealistic.

Back in Washington, Federal Reserve Chairman Alan Greenspan, brought up a topic that was not designed to please voters, but was a more honest assessment of a critical issue facing America - the looming crisis in Social Security. Greenspan suggested that to avoid the retirement of the baby boom generation from bankrupting the Social Security Trust Fund, benefits should be scaled back a little and the retirement age should be nudged upward.

Sensible suggestions, but not politically popular. Apparently, only an unelected official not concerned with re-election can speak with such honesty, saying things people don't want to hear.

Not surprisingly, the Democratic candidates blasted Greenspan's suggestions, promising they would never do anything to reduce benefits or materially change Social Security.

Responsible voters, however, should question the honesty or intelligence of such a response. Simple facts and demographic data suggest the current Social Security system will collapse if no significant changes are made.

To put things in perspective, it is helpful to understand that in 1945, just ten years after the act was created, there were 42 workers supporting each retiree or beneficiary. Over the years coverage was expanded and benefits increased.

But trouble is on the horizon. Twenty years from now, when most of the baby boomers will have retired, there are projected to be just 2.25 workers for each retiree.

That alone, makes it clear that Social Security will not survive a business-as-usual approach.

The impact of the massive baby boom generation is central to the problem. But so is the fact that people are living longer than they did in the 1940s, which means more years of drawing Social Security even though the years of contribution have remained the same.

In the early years of Social Security, the average retiree was likely to live less than 10 years while collecting benefits. In the coming decades, many people are likely to live 20 years or more beyond the current retirement age of 65, collecting benefits over all those years.

A small reform effort in 1983 resulted in the eligible retirement age gradually increasing to 67 between 2000 and 2020. Clearly, this is not an adequate adjustment to reflect today's longer life expectancies.

Greenspan, 77, also suggested that cost-of-living increases be pegged to something called the "chain-weighted CPI," a version of the consumer price index expected to indicate lower inflation. This too, would help Social Security survive by slowing the growth of benefit payouts.

Further reforms might involve permitting younger workers to put a small portion of their Social Security funds into mutual funds or some other conservative equity investment. President Bush has expressed support for this in the past, but Democratic opposition and the recent stock market slump weakened support for such a "partial privatization" approach.

Still, it is worth noting that certain state and municipal workers around the United States, estimated at close to five million workers, have "opted out" of Social Security. These workers' retirement funds are considered defined-contribution plans and have historically outperformed traditional Social Security returns by significant margins.

The independent retirement plan created for city of San Diego workers in 1981 is returning more than double the returns of Social Security funds. The real assets associated with each city of San Diego workers' retirement funds are invested and growing at market rates, historically about eight percent. This is in stark contrast to Social Security, which is a pay-as-you-go system in which no funds are actually invested in the equity markets.

Social Security continues to generate controversy and remains a favorite topic for political rhetoric. The pending crisis is not speculation or scare-mongering, it is a certainty. Any presidential candidate who flatly condemns Greenspan's suggestions and promises no changes to the system is ignoring reality - and increasing the risks to the retirement income for millions of Americans.