Martin Bird, of consultants Hewitt Associates, said retaining control of the scheme's assets was important when there was still a need to tackle pension fund deficits.
Central banks could both provide monetary stimulus and act as willing buyers for government bonds through quantitative easing (QE), making it easier to fund deficits.
Governments also find it easier to fund deficits during recessions, when nervous investors are only too happy to shelter behind the safety of government bonds.
One method is already being employed, namely class-action lawsuits by beneficiaries against trustees; this may increase, given the big fund deficits.
"We aren't going to make up the funding gap by taxing electric vehicles, given how many are likely to be sold with even the most optimistic projections and the size of the trust fund deficits," he said.
The review team found a city troubled for years with cash shortfalls — including one expected to reach $100 million by June — as well as repeated general fund deficits, dealt with mostly by issuing long-term debt.
