Several Harvard political experts yesterday agreed that Budget Director David Stockman's recently published comments doubting the feasibility of President Reagan's economic program would damage the credibility of the policies, but most felt that Stockman's resignation would have hurt the Administration even more.

"He's one of the most competent members of the administration--in the long run, [keeping him] is to Reagan's advantage," R. Shep Melnick, assistant professor of Government, said.

Stockman's controversial statements appeared in the December issue of The Atlantic Monthly. In an article based on a series of interviews with the budget director, Stockman says he and other members of the administration "didn't think it through" and "didn't add up the numbers" of the new economic program. Stockman offered his resignation Thursday, but it was not accepted by Reagan.

"It would have been more damaging if he had left," said Ellen Hume '68, a fellow at the Institute of Politics and a Washington correspondent for the Los Angeles Times. But she added that his statements will make it very difficult for Stockman to deal with Congress in the future.

Some professors, however, said that the statements--which Stockman himself described Thursday as "loose talk"--came as no real surprise. "The comments were a usual case of putting their feet in their mouth. I didn't think it was anything very startling one way or another--Stockman has done enough damage already," Sidney Verba, professor of Government, said.

Meanwhile, some Massachusetts congressmen yesterday sharply criticized Stockman's remarks, citing them as proof that Democrats who opposed Reagan's policies had acted correctly.

A spokesman for House Speaker Thomas P. O'Neill (D-Mass.) said O'Neill felt Reagan's "credibility and the credibility of the program he espouses are severely in doubt." He added, "The Speaker says he has known [Stockman] for years and he is subject to whichever way the wind blows."

"Mr. Stockman and the administration don't know what they're doing," Brian Delany, a press secretary to Sen. Edward M. Kennedy '54 (D-Mass.), said.

But Delaney added that he saw at least one possible benefit from the Stockman controversy. "Congress will now take a serious look at the programs and philosophy of the Reagan administration," he said.