“Charles Ponzi, an Italian immigrant, started the first such scheme in Boston in 1916. He convinced some people to allow him to invest their money, but he never made any real investments. He just took the money from later investors and gave it to the earlier investors, paying them a handsome profit on what they originally paid in. He then used the early investors as advertisements to get more investors, using their money to pay a profit to previous investors, and so on.
To keep paying a profit to previous investors, Ponzi had to continue to find more and more new investors. Eventually, he couldn’t expand the number of new investors fast enough and the system collapsed. Because he never made any real investments, he had no funds to pay back the newer investors. They lost all the money they “invested” with Ponzi.
Just like Ponzi’s plan, Social Security does not make any real investments — it just takes money from later “investors,” or taxpayers, to pay benefits to earlier, now retired, taxpayers. Like Ponzi, Social Security will not be able to recruit new “investors” fast enough to continue paying promised benefits to previous investors. Because each year there are fewer young workers relative to the number of retirees, Social Security will eventually collapse, just like Ponzi’s scheme.” (Read more from The Motley Fool)
Ron Paul on Social Security during the Republican debates: