WHAT HAS BEEN the effect of domestic budget cuts sought by the Reagan administration and voted by Congress? The report just prepared by the Congressional Budget Office on changes in human resources programs since 1981 does about as good a job as is likely to be done, between now and the 1984 elections, of pointing toward the answers. It shows what spending would have been in 1982-85 under laws as they were in 1981 and what it is or is scheduled to be under the laws of 1983. No one is likely to propose major changes in domestic spending this year or next, and none is likely to be approved by a Congress split between Tip O'Neill's Democratic House and Howard Baker's Republican Senate. So the CBO's numbers should be useful not only in 1983 but for 1984.

We don't need to pause too long over the conclusion trumpeted by Speaker O'Neill: that benefits have been reduced most for low-income families. Of course they have. "Human resources" programs (which include two-thirds of domestic spending, with the biggest item not included being interest on the national debt) are intended to help low-income people, and so of course reductions will tend to affect them most. But it's at least possible that some such money is misallocated or is more than the nation can afford. So it's important to look more specifically at the cuts.

When you do, what you find is that means-tested programs, those whose beneficiaries must have low incomes, were cut more than non-means-tested programs. Social Security was cut some 3 percent, for example. But Aid to Families With Dependent Children and food stamps were each cut 13 percent. Child nutrition programs were cut even more, although the Women, Infants and Children program was increased at Congress' insistence. Hundreds of thousands of working poor were cut from the AFDC rolls altogether, and other AFDC and food stamp recipients had their benefits cut. These changes, plus cuts in housing subsidies and the imposition of Medicare and Medicaid charges, must be having serious effects on millions of hard-pressed people.

Less clear is the effect of decreases in education and jobs programs. Education spending was cut by nearly $10 billion. But the federal government accounts for only a small percentage of total education spending, and states may make up much of the federal cuts. States like California and Michigan, though fiscally hard-pressed, voted big increases in education spending this year. Cuts in Pell grants and other aid to students may keep some students out of college. But many students will find the money elsewhere, and some of the money cut may just have gone to higher tuitions. As for jobs, Public Service Employment was, in budget language, "zeroed out" altogether; job training and the work incentive program were cut by one-third. Yet the very fact that the Democrats did not push to restore that money in 1982 and 1983 when unemployment was over 10 percent suggests that most politicians agreed there was a high quotient of boondoggle in these programs.

So the picture of spending cuts the CBO presents is not so one-sided as Mr. O'Neill would suggest. But neither does it support the view that no one seriously in need is hurt. Some of the budget cuts have made it much more difficult for some Americans--the working poor, low-income single mothers --to scrape by, and at a time when the private economy failed to generate the growth and the jobs that Mr. Reagan was predicting in 1980 and 1981.