Has it been duly recorded how America's liberals recently improved on the political economy of Robin Hood? Stealing from the rich and giving to the poor transformed the merry populist of Sherwood Forest into a legend, but it did not make him prosperous. Moreover, it made him a lot of enemies among the rich, and the poor were not all that grateful -- biting the hand that feeds being an adage built on sociological evidence that goes back a long way.

Our huge government programs of recent years were often based on much sounder political and economic insights. The Robin Hoods of the Great Society and its miraculous successors realized that one could get a lot more loot by robbing the middle class and far fewer enemies by giving to the rich -- farmers, doctors, builders -- as well as to the poor. Thus were created such monstrous programs as food stamps, Medicaid and, most stupendous of all, urban renewal. With programs like these, our would-be Robin Hood discovered that they could minister to the poor and still be invited to The Hamptons for brie and chablis.

The mulcting of the middle class for the benefit of the poor and the rich is luminously manifest in the activity of the Public Broadcasting Service. Established as an alternative to commercial television, PBS's special audiences were the poor and the rich. The poor were to get educational programming and local access. The rich were to get culture. In these endeavors PBS has been tolerably successful. It has been particularly successful in cultural programming. Four nights a week it brings splendid productions of the performing arts to the tube.

Unfortunately, it has also been expensive. Federal aid to non-commercial television has swollen from a few million dollars in the late 1960s to more than $200 million in 1980. The Reagan administration wants to decrease this sum over the years ahead until the taxpayers' bill comes to only $100 million. I say this will still be highway robbery.

There are in Washington and elsewhere in the land a growing number of Reagan supporters who judge the Reagan administration's budget cuts moderate. They believe that the growth of government over the past 15 years has been extravagant to the point of seriously debilitating our productive power, and they believe many of the programs that have accumulated ought not to be pruned but rather abolished.

Lewis Lehrman, chairman of the Rite Aid Corporation, says "the Reagan administration's present budget cuts are necessary but not sufficient. The budget program heads in the right direction but only a budget balanced at the current level of tax receipts will restore financial order. Thus the cuts should be deeper." In the case of PBS, the cuts can go $100 million deeper.

Doubtless there are some areas of the budget where the Reaganites would cut too far. The cuts now planned for National Science Foundation programs in science education come to mind, as do NSF programs in social science research. But PBS is about to be rendered thoroughly obsolete. Its funding will be merely a waste. Why not phase it out totally?

Advances in television technology are about to give the highbrows their cultural broadcasting and the poor their local access without costing the taxpayers anything at all. Very soon every home will be able to have as many as 60 channels linked to its television. Dics and cassettes are already available. Now a half-dozen new commercial programmers are laying their traps for the PBS audience. Already one of these commercial programmers has lured the British Broadcasting Corporation away from PBS. In time, all that will be left will be PBS's 250 local stations and its costly bureaucracy.

ABC and CBS believe that they will be able to lure away PBS's highbrow audience and are making elaborate plans for their own cable networks. Apparently, many at PBS suspect these commercial ventures will succeed. Some are exiting PBS to form their own production companies. Others are letting up a howl. There really is no reason for howls. Rather, let us have some applause. PBS under Lawrence Grossman has shown that there is an audience, admittedly scarcely 5 percent of the whole television audience, eager for cultural fare. Working with such public stations as WNET in New York and WGBH in Boston, Grossman has created many useful programs. But now it is time to get PBS off the taxpayers' backs -- and at a savings of $100 million.