Earlier quoted context omitted.
You can have a "contract of the generations", where the younger generation finances the pensions of the older generation through social security payments. Many countries do it like that.
That's a ponzi scheme. That's what many countries in Europe do and that is currently collapsing. It takes something like 4 active workers to pay the pension of 1 current retiree. The proportion was fine after the baby boom, it's not anymore and it's getting worse.
Not surprised you're using a throw-away username and I'm going to downvote it accordingly.