From the abstract:
During the past year, the 100 largest U.S. public pension plans (as measured by accrued liability) reported assets of $2.705 trillion and accrued liabilities of $3.600 trillion, for an aggregate underfunding of $0.895 trillion and an aggregate funded ratio of 75.1%. However, the asset values the plans use for reporting purposes reflect asset-smoothing techniques, which are designed to minimize fluctuations in contribution amounts but may deviate significantly from market value. The liabilities the plans report may not reflect current views on future investment return levels.
The Milliman 2012 Public Pension Funding Study–using actuarial principles, reported liabilities, current market values of assets, and current views oninvestment return–determines that these plans have assets of $2.513 trillion and accrued liabilities of $3.706 trillion, resulting in aggregate underfunding of $1.193 trillion and an aggregate funded ratio of 67.8%.