You pay. The idea is that your future pension is paid by yourself gradually over your productive years. Generally speaking of course - some have no work ever,

You pay. The idea is that your future pension is paid by yourself gradually over your productive years. Generally speaking of course - some have no work ever, some do and pay more, some die before they get some of it, and so on. Complex calculations though, since we can't know the situation 40 years ahead, perhaps not even 5 years ahead.