I had an off the record briefing about Hermes (the uk's largest pension fund) for some reason the government makes pension funds appear to have major short falls by assuming that magically all the members will suddenly start drawing their benefits all at once.
On more reasonable forecasts the scheme was sightly under on more positive estimation it was actually in surplus.
Cynics might think that FS pensions are being made artificially expensive to allow employers to kill of the schemes.
On the other hand, government entities don't have to abide by ANY laws regarding funding for future benefits, so the politicians and union leaders/elders promise higher and better benefits to get the votes, while taxpayers get shafted when the bill comes due. It's ridiculous to promise full retiree healthcare (even the US government doesn't offer it to its citizens). That is why when Congress required USPS to prefund the benefits, it became an issue for their budget. Because when benefits actually get accounted for, and you start setting money aside, you realize how stupid it is to offer someone full retiree medical benefits.
Pay as you go can work for core civil service jobs - its just that it makes it hard to privatize the jobs.
I trust congress and the house also required pre funding of their benefits :-)