Again, putting aside money to meet the obligations you will incur for having an employee today is funding. It is not prefunding by any stretch. I haven't seen

Again, putting aside money to meet the obligations you will incur for having an employee today is funding. It is not prefunding by any stretch. I haven't seen any mention of setting aside money for people who don't work there yet, including in your link. Asking to be treated like the government so that you can hire someone now, with promises of future payments, then pull in those payments based upon the revenue produced by future employees is analogous to a ponzi scheme. The federal government gets away with pay-as-you-go because they can set taxes, devalue money, change payment plans, etc... How much the government should be investing in providing a quality mail system is a different discussion entirely. But this discussion is basically "should pensions be funded or not". Calling it prefunding is a rhetorical device only, and doesn't stand up to actuarial scrutiny.