Worldviews clashed Tuesday as New York Times columnist and Princeton economics professor Paul Krugman debated the director of health and welfare studies at the Cato Institute, Michael Tanner, at the New York Society for Ethical Culture. The subject was “Social Security: Is It Really a Crisis?”

Any doubt of being on the Upper West Side was quickly dissipated when Kate Loverly welcomed the audience, described the Ethical Culture Society’s support for issues such as reproductive freedom and separation of church and state, and announced an upcoming WBAI Fund-raiser that will feature Phil Donahue, Amy Goodman, and the first court-martialed Iraq War resister, who has just been released from jail.

Joshua Micah Marshall of TalkingPointsMemo.com offered intermittent commentary, and the evening was cosponsored by the Century Foundation, openDemocracy.net, WBAI Pacifica, Democracy Now!, Democrats.com, and the Nation magazine.

Mr. Tanner said Social Security reform was not an option but a necessity. We face unfunded obligations of $12 trillion – “That’s real money, even in Washington.” Reform was an opportunity, he said, for citizens to gain ownership and control over their money. Under the present system, he said, “Social Security turns us all into supplicants” with hat in hand to Congress.

“Maybe to people inside the Cato Institute,” Mr. Krugman said, those “collecting Social Security benefits look like supplicants.” He said that only in the ivory tower of a libertarian think tank could this program be seen as creating dependency. “It doesn’t feel that way socially.”

In introducing Mr. Krugman, moderator Vered Mallon had to compete with an overzealous audience member who continued clapping through her introduction and gave him a solo standing ovation before he uttered a word.

Mr. Krugman said Social Security was neither a pension fund nor an investment fund but a social-insurance program to protect people against misfortune, designed to help those “really in need.”

One can think about Social Security as a stand-alone problem or as part of the federal budget as a whole, he said. “We don’t talk about the deficit of the Defense Department,” he said.

Lastly, Mr. Krugman said, “This is not a debate about solvency.” The issue on the table is privatization, a term he said the Cato Institute had changed to “choice.”

Mr. Marshall brought up the topic of why the White House went down this path. He said they decided it was a popular reform and put the best case forward but fooled themselves into thinking it would be easy to garner support. Among other problems, he said, was that White House political interests are different from those of congressional Republicans.

Mr. Tanner spoke next, saying “the longer we wait,” the more difficult the problem would become. It’s a problem we can deal with, and there is moral obligation not to lie about promised benefits that we will not be able to afford in the future, he said.

Mr. Krugman said retirement planners speak of three legs of a stool: private pension, personal savings, and Social Security. “Why remove one leg?” he asked.

Mr. Krugman called the Social-Security reform “crisis-mongering.” As for trying to predict events in 2050, he joked, barbarians from Canada could overrun America by then.

Ms. Mallon asked Mr. Tanner about the richest 1% in American owning as much as members of the bottom 90%. Mr. Tanner said he was sure Mr. Krugman’s next question would be a “softball like that.” He said he was very concerned about the growing wealth gap.

Mr. Krugman said the riskiness of ordinary middle-class lives has been increasing, and that privatization was going to expose people to more risk.

Asked about handling economic calculations, Mr. Marshall joked, “I represent people who got bad grades in high school.” About the relative popularity of privatization among young people, Mr. Marshall suggested, to audience laughter, another way of looking at it: “Maybe young people don’t know a lot about retirement.”

Discussion turned to how privatization has fared in other countries, namely Britain and Chile. Mr. Tanner agreed the British model is very poorly designed but said a Chilean example was more promising: “The fees in Chile are quite low.” Mr. Krugman said that in Chile, the rate of return on private accounts has been pretty good, but noted the situations were not parallel, unless, he joked, one could invest at low prices after a “near-civil war” and “coup d’etat.”

Mr. Tanner said, “Let’s stop patronizing poor people and make them wealthier.” Mr. Krugman replied that using the low-income worker as a “poster child” is unfair to the current system.

Mr. Krugman also criticized the type of system being discussed by the Bush administration. “We are told it’s not going to be expensive to run and one would choose from a limited number of index funds, but who chooses what’s in those index funds?” Mr. Krugman asked. He said that “the weird thing” about the whole debate was that “liberals kind of like America the way it is” and conservatives want to change it.

Mr. Tanner said the fundamental question was, “Do you get to make decisions about your life, or do other people make them for you?”

After the event, audience member Ken Fischetti said the program was stacked two against one. Paul Berkowitz said, “Nothing was lost,” in that both sides amply made their points. Samuel Fenster, who disagrees with Mr. Tanner, acknowledged that the latter was “brave to venture into the Upper West Side.”