Why opponents of Social Security are lying when they say it's a "Ponzi scheme"

Paul Krugman shoots down one of the favorite arguments of the let-Grandma-eat-catfood crowd, the idea that Social Security is a "Ponzi scheme", in Things That Aren’t Bubbles 10/22/2012:

Take the common claim on the right that Social Security is a Ponzi scheme because the system has few real assets. It's true that Social Security is mainly a system in which each generation pays for the previous generation’s retirement, in the expectation that it will receive the same treatment from the next generation. But like monetary circulation, this process can go on forever; there's nothing unsustainable about it (yes, demography, but that's about the levels of taxes and benefits, not the fundamental nature of the scheme). So there’s nothing Ponziesque at all.

Tags: grand bargain, paul krugman, social security