When you pay your prsi contributions you are also buying a claim on future government prsi receipts, the same as someone retired now getting a pension is recouping their bonds purchased during their working careers through their prsi contributions. The bond analogy works both ways and also we know the chaos and instability that ensues when governments (usually from developing countries) renege on paying back those bonds. Therefore a government can never renege on their social insurance obligations, however at least with a funded model they can say you didn't pay in enough into the fund to get back a full state pensionEven with a funded pension scheme, the fund largely invests in equities and government bonds. And what are they? Government bonds are a claim on future tax receipts; as interest and/or redemption proceeds fall due governments tax businesses and/or employees to pay the amounts required.