The report was written by Jeffrey Brown of the National Bureau of Economic Research and the University of Illinois, and three members of the Brookings Institution – Douglas J. Elliott, Tracy Gordon and Ross Hammond. 

"Our in-depth review of the PBGC's models indicates that they are likely to underestimate how bad things can get when the economy is weak," said Brown. "The implication is that the financial risks facing the system are much greater than widely believed."

The report identified three areas of concern about management of the forecasting tool:

• Some of the model documentation is internally inconsistent and outdated;
• The process for updating data and model parameters appears, at least to external observers, ad hoc;
• There does not appear to exist any publicly available, systematic inventory of any robustness checks that might have been performed.

"Other longterm models that are important to federal programs – such as the actuarial models underlying the report of the Trustees of the Social Security and Medicare programs – regularly undergo an external review by a technical panel of outside experts, a process that has led to continual improvement of those models over time," the report noted.

The PBGC was established in 1974 as part of the Employee Retirement Income Security Act. The report said that PBGC premiums, mandated by Congress, are quite small. In 2012, the agency collected $2.6 billion in premiums, but paid out $5.8 billion. It had $82 billion is assets and projected future liabilities at $105 billion.