That is a myth (or depending who you talk to a purposeful lie by the Postal workers union). They don't have to pre-fund for future workers. They only pre-fund

That is a myth (or depending who you talk to a purposeful lie by the Postal workers union). They don't have to pre-fund for future workers. They only pre-fund over the time it takes for the worker to get a pension. But they have to fund the whole cost of the pension. So if you are starting as a postman tomorrow, they don't have to save anything. But if it takes 20 years to get a full pension, each year they have to save 1/20th of the total cost of your pension (estimate for the next 75 years). All government should operate on an accrual basis. I wouldn't demand they hold the funds, but it should count as part of the national debt.