Social Security has enjoyed rock-solid political support for almost all of its 60-year history. Now it's beginning to look as movable as a continent. Long before they know the words "plate tectonics," children playing with a jigsaw map of the world observe that Africa and South America fit together. It's easy for children to say that, because they don't have to provide an explanation of how it could have happened. But before there was a plausible mechanism to explain how continents could move, scientists were leery of making the claim that is so obvious to children. Of course, plausible is a subjective term. Not everyone would chose to apply it to the theory that the continents are so light they are floating apart like bubbles on the surface of an earth churning with currents of boiling rock and metal. To people entering the work force, the vulnerability of Social Security is as obvious as the fit of the puzzle pieces. One survey showed young adults had more confidence in extraterrestrials than they did in the future of Social Security. But politicians have been leery of admitting the obvious. They suspect it will be harmful to their careers to say Social Security is doomed, especially if they have nothing plausible to put in its place. But there is a plausible alternative on offer: a completely private old-age security system to replace Social Security. And for those who find that idea as likely as floating continents, Jose Piņera has provided something even better than an explanation. As Minister of Labor and Social Security in Chile from 1978 to 1980, he has provided a demonstration. Piņera is now a co-chairman of the Cato Institute's project on privatizing Social Security, and he came to San Francisco Wednesday to talk about the Chilean experience at a Cato seminar. Chile actually established its pay-as-you-go retirement system in 1925, 10 years before the United States adopted it as a treatment for Depression symptoms. And Chile recognized the unfortunate side effects of socialized retirement sooner, too. In 1980 it converted its government-run pension system to one where workers invest and own their retirement savings individually. With 15 years' experience behind it, the conversion has been a success. Nearly 90 percent of Chilean workers opted for the new system, though it was not mandatory, and as they retire they are enjoying pensions 50 to 100 percent higher than they would have had under the old system, funded by their own assets rather than taxes on other people. Chile's growth rate has doubled from 3.5 percent a year for decades before the switch to 7 percent since, Piņera said. The nation's savings rate has nearly tripled. The total assets in all the companies that invest retirement funds equal about 40 percent of Chile's gross national product now, and when the system reaches a steady state, around 2008, total assets will approximately equal GNP. This is an enormous pool of capital now available for long-term investment in infrastructure projects, like toll roads and bridges. Thus more saving for retirement translates into more jobs. The way the U.S. does it, the more money we take for Social Security payments funded by taxes, the fewer jobs we have. Workers in the Chilean plan must put 10 percent of their earnings in a regulated, but private, pension savings account. At their option, they may contribute up to another 10 percent. To find out how much to save for the future they prefer, they can play "what-if" on the computers in their pension company's office "Some people want to go fishing at 55," Piņera said, while others want to work longer. "A socialized system cannot account for these divergent preferences, and it exacts a huge price in human happiness." The change has brought significant cultural changes, Piņera said. Strikes have almost vanished as workers realize they own big chunks of the companies they work for. "We are not masochists," one labor leader told Piņera. "We like strikes against someone else." The transition went smoothly because it addressed the separate concerns of three age groups. For those already retired, nothing changed. People currently in the labor force could choose whether to stay in or escape, and if they chose the new plan they received a "recognition bond" worth the real value of their contributions plus interest, to be paid at retirement. Most opted to switch. And new workers automatically joined the new system. The idea is, as intended, so simple "that every taxi driver can teach it to you between the airport and the center of the city," Piņera said. He's even been able to teach it to some other South American leaders. Chile was the first, but it's no longer alone. Peru converted in 1993, Argentina and Colombia in 1994. He's had discussions with Bolivia, Mexico and El Salvador, Piņera said. On other continents he's had slightly less success, though Europe's sclerotic welfare state desperately needs mending. "We are Europeans, we have 2,000 years of civilization" is one response he gets, as if no good idea could possibly come from anywhere else. Americans may not worry about the source of a good idea, but neither are they worrying enough about the consequences of the bad one we adopted 60 years ago. Social Security's cash flow will turn negative around 2012, meaning taxes will have to be raised to begin paying back the money the government has borrowed from the so-called "trust fund." By 2029 or sooner, even that fiction will be exhausted. As any child can see, the solution is obvious.