里克·佩里（共和党总统候选人）讥讽美国的社会保险为“庞氏骗东篱把酒黄昏后局”，引起了轩然大波，经济学家以及其他学术权威也卷入了这场争吵。左派博客 Matt Yglesias说只有疯子才会说出这番话来，因为社会保险依靠的只是未来的经济增长——就好象私人退休计划一样。自由市场经济学家Alex Tabarrok则用新凯恩斯主义者同时也是诺贝尔奖获奖者保罗·萨缪尔森和保罗·克鲁格曼的文章来回应 Matt Yglesias，他们都把社会保险与庞氏骗东篱把酒黄昏后局相提并论。
在这篇文章中，笔者将会论述三个观点：首先，我会指出对于社会保险的批评是正确的，社会保险之所以“行得通”，就是因为它与庞氏骗东篱把酒黄昏后局的相似性；第二，我会说明私人退休计划与社会保险是完全不同的。第三，对于查尔斯·庞齐本人（庞氏骗东篱把酒黄昏后局的发明者），我要维护他的名声，把他的所作所为与社会保险相提并论是下流的，他丝毫不像社会保险那样采取敲诈勒索的方式。
社会保险的“庞氏骗东篱把酒黄昏后局面目”
保罗·克鲁格曼以经常夸下海口著称。有时候，他会因他说过的话而自食其果。对此，克鲁格曼通常的做法是否认，认为大众媒体误读了他过去的专栏文章。例如克鲁格曼在2002年写的这篇文章就被认为纵容了格林斯潘制造房地产泡沫，对此克鲁格曼表示难以置信，人们竟然会如此解读。
当提到社会保险，克鲁格曼在1996年是这么写的：
“从受社会保险保障的人士的角度来看，社会保险的构造与一项平常的退休计划无异：你付出多少，将来就会得到多少。所以这并不是一项劫富济贫的制度。虽然实际上，这个制度的确已经产生了劫富济贫的效应。一代人所获得的多于付出的。不过，由于人口结构的改变,这种现象将会不复存在，从今以后被保险人只能获得他们所投入的（而现在的年轻人也许会比较吃亏）。”
正如那篇关于房地产泡沫的文章，克鲁格曼这次也不得不为这番言帘卷西风论灭火了。在这篇文章重新被发现，在网上传播之后，克鲁格曼尝试制止人们的讥笑，声称任何打算利用这篇文章来支持共和党人观点的人都是在玩“文字游戏",然后他放出一个链接，介绍庞氏骗东篱把酒黄昏后局的诱人历史，而资料来源竟然是美国社会保险总署（Social Security Administration下文简称SSA）！（看来这个机构掌握了很多庞氏骗东篱把酒黄昏后局的资料哦）
我很好奇SSA是怎么辩护这不是一个庞氏骗东篱把酒黄昏后局的。下面是他们的说法：
“”与庞氏骗东篱把酒黄昏后局依赖不可持续的资金流入相比，社会保险的量入为出（pay-as-you-go）系统是很正常的财务安排。社会保险与某些私人养老计划一样，使用相同的设计。一套量入为出的系统可被视为一条管道，今天的投保人把钱放进前面的管口，而受益人就从后面的管口取走钱……
“与庞氏或金字塔式传销骗东篱把酒黄昏后局相比，量入为出系统的确有表面上的相似性，即后来参加者的资金将会用来支付给先前的参加者。不过这种相似性仅此而已……
“只要流入管道的钱和流出管道的钱保持大致上的平衡，这套系统可以永远运行下去。量入为出系统里面并不存在不可持续的进程，因此它不是庞氏或金字塔式骗东篱把酒黄昏后局。”
我的看法与Yglesias、克鲁格曼和SSA相反，对于社会保险是“庞氏骗东篱把酒黄昏后局”的指控，我认为是十分恰当的。当人们批评社会保险“不可持续”的时候，他们的意思显然是，在维持税率及社会保险给付不变的情况下，社会保险不可能维持下去。要么加税，要么减少保险金，或者双有暗香盈袖管齐下。克鲁格曼1996年的专栏文章承认了这一点。SSA的管道同样也是不可持续的。
今时今日，退休人员依然拿到比他们付出要多的退休金，只能通过吸收更多的工人加入社会保险来维持这个制度，而这显然是不能持续的。换句话说，这就是一个庞氏骗东篱把酒黄昏后局。我在这里并不是要为里克·佩里站台，不过他说的显然是真理：人口结构会发生改变，不可能每一代人都能从这个系统中拿到比自己所付出的还要多的钱。
SSA的管道论很有趣。如果社会保险的确是这样的，也就是每一代投保人都只能获得他们“当初给的保险金”，那就意味着他们为这个系统作出了“贡献”，而回报率是零。
没错，在这种情况下，社会保险至少从会计学上来说是“可持续的”（在人口构成保持稳定的前提下），但这在政治上可行吗？如果政客诚实的告诉选民“我们会在你25岁的时候拿走1000元，别担心，那1000元会在你65岁的时候还给你”，你猜选民们会接受这样的安排吗？查尔斯·庞兹也可以让他的骗东篱把酒黄昏后局具有“可持续性”，只要他告诉投资者收益率是零就可以了，但这样就没有人愿意投资了。
公正地说，正如Matt Yglesias所言，通过管道是有可能获得回报的。如果工人不停地把他们的钱，比如工资的15%，放进管道的左边，50年之后，如果经济能过如常增长的话，工人的投入的确有可能增值。但庞氏也有可能令资金增值。每一代人都还是得到多于付出。按照克鲁格曼的说法，这依然有着“庞氏骗东篱把酒黄昏后局的面目”。因此，无论Yglesias如何构造社会保险，面对着人口的变动，社会保险依旧是不堪一击。
为什么私人退休计划行得通
公众讨论社会保险时的困惑，部分是由于他们普遍忽视了，一个社会事实上可以通过储蓄和投资实现共同富裕。换句话说，他们往往相信（不管有没有经过深思熟虑），如果要让张三每年有一万块储蓄金，那就意味着要从在某处的李四那里拿走一万块。因此，当张三需要依靠存款过活，就必须以牺牲李四的生活水准为代价。这种想法源于公有制，在公有制的情况下，所有财产都是一个整体，我们需要的只是根据人们需求的多寡而对“总产出”的分配作出调整而已。
这个想法是完全错误的。我曾在我的书中系统地阐述过这一点，这里我只讲其中的要点：社会中的每个人都可以低于自己收入的水平去生活，也就是支出少于收入，把剩余的钱存起来。
设想一下这个情景：在一个农民的工作生涯里，他每年把收成的一部分用来购买拖拉机组件，第一年买轮胎，然后买转向盘，持之以恒。到了45岁的时候，农民准备退休了。他终于组装了一台全新的拖拉机。他不需要亲自劳动干活赚钱了，现在，他可以把拖拉机租给其他年轻的农民了。(否则他们只能够用双手干活了)
显然，退休的农民不再工作后，所吃的每一分粮食都是“不劳而获的”。退休农民的粮食来自其他人的生产。虽然如此，退休农民的生活、消费并不依赖于年轻人的“贡献”或者“分配”。
而年轻的工人，不用交保险费，反而可以完全获得市场提供的薪酬（如果他们精明的话，还可以为了日后的退休生活进行储蓄）。退休的农民可以利用拖拉机的租金在市场上购买粮食。而得益于这个农民组装的拖拉机，还有其他人生产的化肥、农具、灌溉设备，粮食的产量因此提高了。
我的故事虽然显然是虚构的，但它揭示了自愿退休计划的精髓。由于庞巴维克所提出的迂回生产理论（庞巴维克，奥地利学派经济学家，迂回生产指的是，通过生产生产资料间接获得生活资料，退休人员利用储蓄或投资，实现迂回生产，获得生活资料——译者注），你所得到的会多于你所付出的。正如我在小布什的社会保障私有化改革的争论中所抱怨的，许多支持市场的改革者想认识利滚利的奥秘，多年来却没有建立储蓄的机制。
为查尔斯·庞兹辩护
上面我解释了在政治辩论的环境下，为什么社会保险是庞氏骗东篱把酒黄昏后局的指控是准确的。然而，很重要的是，这个指控是不公平的，对查尔斯·庞兹是不公平的。
没错，庞兹的确犯下了诈骗罪；受害人如果确切地得知庞兹的盈利模式，他们是绝对不会进行“投资”的。古典自由主义者也会认为像庞兹这样的行为构成犯罪，在任何公正的法律制度下都应该受到制裁。
但是就我们所知，庞兹并没有威胁、恐吓任何人。他并没有告诉努力工作的工人“你们必须没周把工资的15%拿出来交给我，将来你会有很美好的回报的——否则我就要把你抓起来了。”
从这个角度看，社会保险毕竟不是庞氏骗东篱把酒黄昏后局。它更类似于黑瑞脑消金兽社会，向民众敲诈保护费，并声称不交的话“后果很严重”。
结论
对社会保险的指控是准确的：它之所以取得“成功”，唯一的原因是依靠新增加的参保工人。如今人口结构已发生逆转，这个制度确实已不可再持续。我们将来我们会面临加税，或者减少退休金，或者二者双有暗香盈袖管齐下。
而在自愿私人退休计划中，人们可以通过自己的储蓄或投资活动，来为自己日后的退休做好规划。由于退休人员之前的收入足够他们在不能再工作的时候利用资本货物获得收入，他们根本不需要靠压榨下一代工人的收入来实现退休。
最后，社会保险比庞氏骗东篱把酒黄昏后局还要危险：庞氏骗东篱把酒黄昏后局依靠的是欺骗，让受骗的人自愿交出财物。一旦被揭穿，危险便告解除。与之相比，美国的工人没有选择，不管他们愿意不愿意，他们只能“持续地”把钱投入社会保险。
译后记
文章虽然提的是美国，但中国的问题似乎更加严重。一方面，老龄化趋势来得更快，另一方面，一些退休干部的待遇与美国相比更是有过之而无不及。现有的社会保险制度能持续下去吗？也许，很快我们就会面临加税，削减退休金，或者开动印钞机的时刻了。
原文：
Ever since Rick Perry derided Social Security as a Ponzi scheme, economists and other pundits have jumped into the fray. Progressive blogger Matt Yglesias says it's "nuts" for anyone to talk like this, because Social Security merely relies on future economic growth — just like a private pension plan. Free-market economist Alex Tabarrok responded to Yglesias with links to arch-Keynesians (and Nobel laureates) Paul Samuelson and Paul Krugman, both comparing Social Security to a "Ponzi game."
In the present article I have three aims: First, I will point out that the critics are right; to the extent that Social Security "worked," it was because of its resemblance to a classic Ponzi scheme. Second, I will show how private-sector retirement planning operates nothing like this. Third, I will defend the good name of Charles Ponzi from the scurrilous comparisons — what he did was nothing like the racket known as Social Security.
Social Security's "Ponzi Game Aspects"
Paul Krugman is a famous guy with a long record of strong opinions. It's to be expected that periodically these will come back to bite him. His usual tack is to deny that his old columns meant what their plain-word reading would indicate. For example, Krugman can't believe anybody thought this column (from 2002) should be construed as his endorsement of Greenspan trying to create a housing bubble.
When it comes to Social Security, here's what Krugman wrote in late 1996:
Social Security is structured from the point of view of the recipients as if it were an ordinary retirement plan: what you get out depends on what you put in. So it does not look like a redistributionist scheme. In practice it has turned out to be strongly redistributionist, but only because of its Ponzi game aspect, in which each generation takes more out than it put in. Well, the Ponzi game will soon be over, thanks to changing demographics, so that the typical recipient henceforth will get only about as much as he or she put in (and today's young may well get less than they put in).
As with his unfortunate housing-bubble article, here too Krugman has had to do damage control. After the above column floated around the Internet, Krugman tried to quell the giggling, claiming that anyone who tried to use him in support of Republican claims was playing "word games." Krugman then gave a link to this fascinating history of the original Ponzi scheme, courtesy of — the Social Security Administration! (It seems they must get this a lot.)
I was curious to see how the Social Security Administration would defend itself from the charge that it was a Ponzi scheme. Here's what they say:
In contrast to a Ponzi scheme, dependent upon an unsustainable progression, a common financial arrangement is the so-called "pay-as-you-go" system. Some private pension systems, as well as Social Security, have used this design. A pay-as-you-go system can be visualized as a pipeline, with money from current contributors coming in the front end and money to current beneficiaries paid out the back end.…
There is a superficial analogy between pyramid or Ponzi schemes and pay-as-you-go programs in that in both money from later participants goes to pay the benefits of earlier participants. But that is where the similarity ends.…
As long as the amount of money coming in the front end of the pipe maintains a rough balance with the money paid out, the system can continue forever. There is no unsustainable progression driving the mechanism of a pay-as-you-go pension system and so it is not a pyramid or Ponzi scheme.
Contrary to the claims of Yglesias, Krugman, and the Social Security Administration, I don't think the "Ponzi scheme" charge is unfair in the slightest. When critics say Social Security is "unsustainable," they quite obviously mean that it can't keep up the current taxing and benefit schedules. Either taxes on workers will go up, promised benefits will be reduced, or some combination of the two. Krugman's 1996 column confirms that analysis, and the Social Security Administration's pipeline does too.
Up until now, retirees have been taking out more than they put in, and that can't continue — this pattern relied on finding ever more workers to join the system. In other words, it was a classic Ponzi scheme. I am not here to endorse candidate Rick Perry, but the point of his charge is obviously true: each generation can't keep taking more out of the system than it put in, once the demographics change.
The SSA's pipeline graphic is interesting. If that is ultimately what Social Security turns into, and if each generation of workers merely takes out "what it originally put in," then it means workers will earn a zero-percent (real) return on their "contributions" into the system.
Yes, that would certainly be "sustainable" in an accounting sense (at least with a stable age distribution in the population), but would it work politically? If politicians frankly told voters, "When we take $1,000 from you at age 25, don't worry, that $1,000 will be waiting for you when you're 65," would they be happy with this arrangement? Charles Ponzi too could have made his scheme more sustainable if he promised his investors a 0 percent rate of return, but then nobody would have been interested.
In fairness, Matt Yglesias points out that the pipeline method can yield a positive rate of return. If the workers at the left end of the pipe always pump in, say, 15 percent of their paycheck, then (if productivity grows over time as it normally does) 50 years later, when they are on the other end of the pipe, there will be more dollars shooting out. However, in this scenario we're back to an arrangement where each generation gets out more than it put in — what Krugman himself thought was a "Ponzi game aspect." In any event, Yglesias's framework is still vulnerable to demographic shifts.
Why Private-Sector Retirement Planning Works
The confusion in popular discussions of Social Security partly rests on the general ignorance of how an entire community can actually become richer through saving and investment. In other words, a lot of people believe (whether or not they've really thought it through carefully) that for every Sally out there who's saving $10,000 per year, there must be some Jim who's racking up $10,000 in debt. Therefore, whenever Sally starts living off her savings, people imagine that Jim must be cutting back on his own standard of living. At the communal level — so the thinking goes — everything is a wash, and we're just changing the distribution of "total output" based on which people were frugal and which were spendthrifts.
This mindset is totally wrong. I explain things methodically in chapter 10 of my introductory textbook, but here's the gist: It's possible for everyone in the entire community to "live below his means," that is, to consume less than his income and to save. The economy is then physically capable of reducing the output of consumption goods (TVs, sports cars, steak dinners, etc.) and increasing the output of investment or capital goods (drill presses, fertilizer, MRI machines, etc.). In the future, the larger quantities of various tools and equipment make the workers more productive than they otherwise would have been. That's why the standard of living can rise; the community is physically capable of cranking out more goods and services because of the past investments.
Think of it like this: During his working career, a farmer takes some of his crop every year and uses it to buy a component for a tractor. One year he buys a tire, another year he buys a steering wheel, and so on. After working for 45 years, the farmer is ready to retire. By this point, he has assembled a brand-new tractor. Now he no longer needs to use his labor to earn an income. Instead, he rents out use of the tractor to the younger workers (who otherwise would have to use their bare hands to till the soil, etc.).
From a certain viewpoint, the retired farmer would be "skimming off the top" every time he ate an ear of corn harvested after he no longer worked the fields himself. After all, that corn would be part of that year's harvest, so if the retired farmer ate it, there would be less corn available to the people who actually picked it. Yet the retired man's consumption wouldn't be financed through a "contribution" or "redistribution" from the young workers that year.
On the contrary, those young workers would be earning their full market wage (and if they were smart, they'd be saving some of it for their own retirement). The retired farmer would buy the corn on the open market, with the income he earned from renting out his tractor. There would be more corn to go around because he had spent decades assembling the tractor, and others in his cohort had built up stockpiles of fertilizer, hoes, irrigation equipment, etc.
Obviously my tale isn't realistic, but it serves to get across the essence of voluntary retirement planning. People can get out more than they put in (measured in physical terms) because of what Böhm-Bawerk called the superior physical productivity of roundabout processes. As I complained during the debates over George W. Bush's "privatization" proposals, many supposedly pro-market reformers want to get the magic of compound interest without the discipline of saving for decades.
A (Very Qualified) Defense of Charles Ponzi
Above I've explained why the "Ponzi scheme" accusation is accurate, in the context of modern political debates. However, there is a very important sense in which it is unfair — unfair to Charles Ponzi.
It's true that Ponzi engaged in fraud; his victims never would have "invested" with him, had he accurately explained the business model. Libertarians therefore agree with everybody else that Charles Ponzi was a criminal and would have to face legal consequences in any just legal order.
However, so far as we know Ponzi never threatened anybody. He didn't tell struggling young workers, "Give me 15 percent of your paycheck every week, so that I can make you a fantastic return — or else I'll send goons to kidnap you."
In this respect, Social Security isn't a Ponzi scheme after all. It's more analogous to mobsters shaking down people for protection money, because otherwise "bad things could happen."
Conclusion
The complaints about Social Security are accurate: The only reason it has enjoyed such "success" thus far is that it relied on increasing contributions from each new generation of workers. Now that the demographics have turned against the system, it is literally unsustainable. We will see increased taxes on workers, reduced payments to beneficiaries, or some combination of the two.
$25 $22
In the voluntary private sector, people can plan for their own retirement through genuine saving and investment. They don't need to extract concessions from the next generation of workers, because the retirees' prior savings allow the creation of capital goods that will provide income when their bodies no longer can do so.
Finally, in one important respect a classic Ponzi scheme is less dangerous than Social Security: It relies on fooling people into voluntarily handing over their money. Once the fraud is detected, the danger is eliminated. In contrast, American workers have no choice but to "contribute" to Social Security, whether they like the deal or not.
