[niggler]

The one sentence summary that explains the entire situation is: the 2006 pension funding requirement change was written and pushed by congresspeople who have taken campaign contributions by UPS and Fedex.

The reality is that most of the losses since 2006 were directly due to the overfunding requirement (they had to prepay 75 years of projected liabilities in 10 years time -- a requirement that no other agency has). They are also prohibited from cutting back service because they need congressional approval to do so (and a bunch of rural congresspeople are pushing back against it), so the USPS is in a real bind where they are being essentially forced to make changes but don't have the authority to do so.