To double down on what user5994461 said, that's indeed a ponzi scheme and quite stupid if you know current population trends. It also creates quite perverse in

To double down on what user5994461 said, that's indeed a ponzi scheme and quite stupid if you know current population trends. It also creates quite perverse incentives, as older folks want to reduce their retirement age (even as they live way longer) and raise the contributions of younger people (to pay for the extra costs).