Welcome to the World of 'Pension Smoothing'

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The bill essentially allows companies to base their pension liability calculations on the average interest rate over the past 25 years, instead of the past two. The 25-year average is larger, because interest rates were much higher before the financial crisis.

The accounting technique doesn't actually reduce companies' obligations to retirees. Instead, it artificially lowers the present-day value of future liabilities by boosting the interest rate companies use to make that calculation.

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But the accounting tactic is controversial... "To use the federal pension insurance program to pay for wholly unrelated spending initiatives is just bad public policy," said Brad Belt, former executive director of the Pension Benefit Guaranty Corporation, the government's pension insurer. "It has adverse implications for the funding of corporate pension plans."