PENSIONS
Interestingly enough USPS pensions have historically been pretty much paid for by the employees who are going to use them.
This gets a bit complicated since there are two different systems involved ~ FERS (the current system) and CSRS (the former system).
With CSRS the government takes about 7% of your salary and sets it aside in treasury bonds (a not uncommon method used by many companies and equity funds). On top of that you can have a non-matched 401(k).
With FERS the government takes a smaller percentage of your salary, but the agency puts a larger percentage into a similar fund. To offset the differences in costs the FERS payout is less than the CSRS (about half for later years of service in fact). In general FERS ends up far less expensive to the taxpayers (or USPS ratepayers) than CSRS. Plus, you can have a matched 401(k) account, etc.
The government does not have any of those notoriously expensive disability packages found in state and local systems, plus, the background funding is adjusted regularly to make sure the whole system is actuarily sound.
In short, the federal pension program ends up being financially neutral.
Your Congresscritters do engage in one egregiously corrupt practice ~ they count each year in Congress as being equal to TWO YEARS in the federal retirement system.
That practice should be eliminated.