Critics of President Bush's Social Security reform plan sure have it easy these days.

All they need do, it seems, is point to the ups and downs -- well, mostly downs -- of the stock market. That's all it takes to confirm the folly of investing in personal retirement accounts, right? Like Al Gore said when he ran for president in 2000, it's a "risky scheme."

So what if Social Security is going broke? That it promises most workers entering the system today less than a 2 percent return on the money they will pay into it? That every relevant demographic trend works against it?

Better the proverbial "lockbox" than a "risky scheme," nervous members of Congress figure. At least "lockbox" sounds safer.

The problem is, it's not.

By the time the first of 77 million baby boomers begin retiring in 2011, barely more than three workers will be around to support each retiree -- down from 16 per retiree in 1950. That means those workers will have to start forking over bigger "contributions" (read: higher payroll taxes). By 2017, Social Security will begin taking in fewer dollars from taxes than it pays out in benefits. After 2043, absent a massive cut in benefits or hike in taxes, it'll be broke.

The Commission to Strengthen Social Security, appointed by President Bush, studied three plans for personal retirement accounts. All would allow workers the option (that's right, folks, it wouldn't be mandatory) of investing a small portion of their annual income in long-term, low-risk accounts. If the accounts prove profitable, workers would receive higher monthly retirement benefits. In the highly unlikely event they don't, benefits would be cut only by the amount they've deposited into their personal accounts.

In short, no one would be wiped out.

The commission's researchers found that, under the commission's second plan, which would allow workers to invest up to 4 percent of their gross income or $1,000 per year, monthly retirement benefits for medium-income workers would rise by an average of 18 percent by 2032 -- and 59 percent by 2052. Why so much? Because the market always pays better over the long run than Social Security does.

The key words are"long run." A long-term, buy-and-hold investment program is what the president proposes. No one with fewer than 10 years to go until retirement would be eligible for personal accounts, and most workers would contribute to them for 30 years or more.

The Standard & Poor's 500 (S&P), the index that measures the stock prices of large companies, has gained every 20-year period since it began in 1926. It even climbed 1.1 percent through the heart of the Great Depression -- 1929 to 1938. The short-term hiccups -- even the 25 calendar years in which the S&P fell, including the six when it fell more than 20 percent -- are more than outweighed by the market's overall upward climb.

The S&P has gone up for the year 51 times since it was first established. It has averaged a 7 percent annual gain over the last 75 years, and it never has had a 30-year period in which it did not gain at least 4.4 percent. In fact, seven 30-year periods since the S&P was created had rates of return of more than 9 percent.

Meanwhile, today's typical 35-year-old man, with average earnings for his age group, can expect to "earn" a minus 0.3 percent return on his Social Security retirement taxes, according to Heritage Foundation Social Security expert David John. That means after paying about $282,000 in taxes over his career, this man can expect only $262,000 in benefits -- a $20,000 loss. His 32-year-old wife would do better, but the typical rate of return for women this age -- 1.9 percent annually -- is still far below even what the most conservative investments would pay. (A simple savings account can outperform that.) And it's only going to get worse.

Social Security may have provided a warm blanket for Americans at the height of the Great Depression. But the blanket now has some holes. Something has to change. President Bush hasn't proposed a "risky scheme." What's risky is doing nothing and hoping our children somehow can solve this problem for themselves.

Alfredo Goyburu is a policy analyst in the Center for Data Analysis at The Heritage Foundation (www.heritage.org), a Washington-based public policy research institute.