“Donald Trump’s suggestion that economic growth alone can solve the problem is not realistic and can hardly be called a plan,” said Robert L. Bixby, executive director of The Concord Coalition. “And while Hillary Clinton’s proposals were more specific, the higher taxes that she suggested would be used for new spending rather than to curb the projected growth in federal debt under current law.”

He added: “Washington is already on course to add trillions of dollars to the federal debt in the next decade, outstripping projected economic growth. So even budget plans that promise not to make the situation worse are inadequate. We must do more than tread water . . .”

Instead of building a mandate for comprehensive reforms, Bixby said, the candidates “are building in unrealistic expectations among their hard-core followers.”

Similar concerns were voiced in a New York Times op-ed last week by Paul A. Volcker, a former Federal Reserve chairman and member of Concord’s Board of Directors, and Peter G. Peterson, chairman of the Peterson Foundation and a Concord co-founder.

“Unfortunately,” they wrote, “despite a brief discussion during the final presidential debate, neither candidate has put forward a convincing plan to restrain the growth of the national debt in the decades to come.”