Turmoil in Europe, the sluggish economy and low interest rates are intensifying pressure on public pension-fund systems to reduce the annual-performance assumptions they use to determine contributions from taxpayers and employees.

Some lawmakers and pension officials are pushing to abandon the roughly 8% annual-return assumption set by many public-employee funds, saying the rate is unrealistically high given upheaval in markets around the world and the preceding financial crisis.

"After 10 years of listening to the experts be wrong on the downside more than half the time, I would like to be more cautious," said James Dalton, chairman of the Oregon Public Employees Retirement System.

The pension system, which covers about 325,000 members, affirmed its 8% assumption this summer despite a dissenting vote from Mr. Dalton. Oregon exceeded its 8% assumed rate over the most recent 20-year period but fell short over five years and 10 years.

Filed Under : Pensions