Sometimes you think it can’t get worse and then you pick up the newspaper. That the story of retirement security. Even as Americans struggle to keep roofs over their heads and their kids in college more than ever have to worry about their nest egg — either their pension fund itself or the stocks inside it. The news is getting worse, especially in the world of multi-employer pension funds.

Multi-employer pension funds are defined benefit plans in which several companies contribute to cover a unionized workforce. This worked well for a long time but has obvious problems, especially as a smaller percentage of young employees are going into that part of the workforce. This is a demographic problem that means fewer young employees pay the benefits promised to older and retired workers.

Now comes a new part of the story: some public companies have not been highlighting their massive unfunded liability to their pension plans, which serves to inflate the value of their enterprise. Thankfully, laws governing this accounting have been improved and firms are now being required to fully disclose these issues, as the Wall Street Journal notes in “The Union Pension Bomb“:

In “Crawling Out of the Shadows,” analysts David Zion, Amit Varshney and Nicole Burnap address the big but opaque world of pensions in which companies across an industry pay into a single asset pool. These 1,400 union-run retirement vehicles have long been poorly run and underfunded. (See “The Next Pension Bailout,” August 16, 2010.) But Credit Suisse has dug deeper and found how really big the mess is.

Among the findings: Multi-employer plans in the U.S. are underfunded by some $369 billion. An estimated $43 billion of that off-balance-sheet liability belongs to the 44 S&P 500 companies that are exposed to multi- employer plans. The other 88% of the $369 billion is borne by small, mid-cap or private firms that may be even less prepared to cover the obligations. The report says Safeway’s $6.9 billion in liabilities amount to 76% of the company’s market cap, for example.

It’s good that we are closer, finally, to a real reckoning of costs that companies face. As the numbers add up, it’s easier to see why so many employers have shifted to defined contribution plans and why so many employees opt out of joining a union where they can be forced into retirement plans that are less than secure.