You can tell the private sector works when even the public sector chooses private over public.
The biggest obstacle to postal reform, by far, is the problem of funding Congressionally mandated pre-retiree health benefits. Since 2006, the Post Office has been legally required to pre-fund health benefits for future retirees at a cost of around $5.5 billion a year. For the first time last year, it defaulted on its annual payment.
“WASHINGTON — Ten months after the Obama administration began pressing lenders to do more to prevent foreclosures, many struggling homeowners are holding up their end of the bargain but still find themselves rejected, and some are even having their homes sold out from under them without notice.”
This lead from a December 17th McClatchy Newspapers article [...]