"I don't think anyone knows where we are going," said Marilyn Moon, a health economist at the Urban Institute in Washington.

Marilyn Moon, a health economist, said: "This needs a lot of vigilance.

Marilyn Moon, a senior fellow at the Urban Institute, said, "The success of this proposal will rise or fall on the generosity of the subsidies."

Marilyn Moon, a health economist who served as a public trustee from 1995 to 2000, said: "It's good to have turnover.

The answer, said Marilyn Moon, an economist at the Urban Institute, can be summarized in three words: "Save like crazy."

Marilyn Moon, a public trustee of the Medicare trust fund since 1995, said: "Most people were caught by surprise at the extent of the reductions.

Marilyn Moon, a former director of public policy for AARP, said it had also become politically bolder.

Marilyn Moon, an economist at the Urban Institute, put the proposals in perspective.

But Marilyn Moon, an economist and former Medicare trustee, said she had little confidence in such long-range projections.

"These are big social questions I don't think anyone can know the answer to," said Marilyn Moon at the Urban Institute.