Il sistema pensionistico pubblico

One very curious governmental activity has grown enormously
in the present century. Its great popularity is a notable
indication of widespread popular ignorance of praxeological law.
We are referring to what is called “social security” legislation.
This system confiscates the income of the poorer wage earners
and then presumes to invest the money more wisely than they
could themselves, later paying out the money to them or their
beneficiaries in their old age. Considered as “social insurance,”
this is a typical example of government enterprise: there is no
relation between premiums and benefits, both changing yearly
under the impact of political pressures. On the free market, anyone
who wishes to invest in an insurance annuity or in stocks or
real estate may do so. Compelling everyone to transfer his funds
to the government forces him to lose utility

Thus, even on its face, it is difficult to understand the great
popularity of the social security system. But the true nature of
the operation differs greatly from its official image. For the government
does not invest the funds it takes in taxes; it simply
spends them, giving itself bonds, which must be later cashed
when the benefits fall due. How will the cash then be obtained?
Only from further taxes or inflation. Thus, the public must pay
twice for “social security.” The social security program taxes
twice for one payment; it is a device to permit palatable taxation
of the lower-income groups by the government. And, as is true
of all taxes, the proceeds go into governmental consumption

Rothbard, "Powern and Market, pag. 225-226