The rest of us may grouse and grumble, but surely big business can have no reason to question the Reagan economic program.

Well, you ought to listen to J. Richard Munro. Munro is president and chief executive officer of Time Inc.--big business by any standard.

He likes what Reagan is trying to do--even considers it vital to the nation's economic health. But the way he is doing it, Munro fears, will spark a popular backlash that will delay for a generation any real hope of revitalizing American business.

". . . I support the new policies that promote growth, new investment, and greater productivity," he said in recent remarks to New York's Union League Club. "For too long, we were putting too little aside for future needs. Our competitive edge has been dulled, and something clearly needed to be done.

"Yet in the rush to fight inflation and stimulate investment, I fear that we have cut too deeply--that we have put too high a burden on the poor and the elderly--and that we are jeopardizing the long-term goals of this program and the interests of business."

He is especially concerned that some 70 percent of the cuts now in place are from programs affecting the poor: job training, education, Medicaid, housing aid, food stamps, school nutrition, jobless benefits, and so on.

"The budget cuts are leaving serious and immediate human needs unmet," he told the century-old organization of business leaders. "And if the budget cuts continue as scheduled, the problems of the poor will worsen intolerably. As business executives, I don't think we should stand by and let this happen."

He explained why. "This year, we have the chance to restore business incentives for greater investment and productivity. The president, the Congress, and, most important, the public are behind us.

"Yet this public support will vanish if the burdens of this program remain so uneven--if people think that the rich and big business get all the breaks, and if the promised surge of prosperity pays off only for those already well off."

Such a conclusion is virtually inevitable, he believes, given the nature of the president's program. The bulk of the cuts already in effect fall on the poor--as, in all probability, will the $13 billion in new cuts recently proposed and the $100 billion in cuts projected for 1984.

"Combined with the tax cuts that benefit mostly higher-income people, this program adds up to a major redistribution of money in our society--from the lower end to the upper end of the scale."

Munro is hardly the first to describe the Reagan approach as a redistribution of income from the poor to the rich. What is significant is that it was said by a top business executive to an organization of top business executives as a guide to their own self-interest.

Business needs the incentives that Reagan wants to provide, he said, and parts of the president's program are working well--notably an easing of the inflation rate. But there is another aspect of the program that smart businessmen should find troubling. The deepening recession and rising inflation will tend to kindle a new wave of inflation, through reduced taxes and increased unemployment and welfare payments. The only way to prevent the inflationary pressure is to reduce the relief payments--which is what Reagan apparently intends to do, despite his talk of "safety nets." In addition:

"While the economy declines, big business mergers are taking place with the subtlety and grace of dinosaurs mating; safety, health, consumer and environmental protections are weakening; civil rights enforcement is taking a giant step backward and the share of taxes paid by corporations drops significantly," Munro said.

"That's not a scenario designed to build confidence in the current program. Consequently, in the next election, people may decide that they're not getting the changes they really wanted. And it will be another generation before we get a similar chance to enact business incentives."

He suggested some things that his fellow executives might do to correct this fatal flaw in the Reagan approach:

They can increase their corporate contributions to organizations that are working to relieve human suffering; they can do more to hire and train young people, providing help in basic skills and day care; they can pursue their own affirmative action programs. And most important, they can work with "our friends in Washington" to restore some of the funding for social programs, to bring the tax cuts and defense outlays to a more reasonable level.

"A booming private economy--built with money withheld from vital social programs--won't help someone who's too old or too young for the job market, who can't find decent day care for their children, who has no job skills, or who is sick or disabled," Munro said.

"And if many of them will be helped in the long run, what do they do in the meantime?"

It's a question a lot of us have been asking.