Thirty years ago, Americans did not use the word ''homeless.'' Millions of people were ill-housed, but except for the occasional skid row derelict, hardly anybody literally lived in the street.

Homelessness, as we understand it today, came from five sources: the closing of state hospitals for the mentally ill; the increase in drug and alcohol abuse; wives and children taking flight from abusive husbands or boyfriends; a street culture of runaway teenagers; and increasingly unaffordable housing costs for the poor.

While the casual observer may see a single subculture of the homeless, there are really several different kinds of homeless people. But each has a social cause - and a social remedy that our society could easily afford.

The largest single group of homeless is the mentally ill.

The tragedy is that 30 years after deinstitutionalization, there are well-established strategies for providing decent housing and noncoercive care to the mentally handicapped.

Here in Boston, the Massachusetts Housing and Shelter Alliance pioneered a strategy called the Special Initiative that combines permanent subsidized small-group or individual housing with support services and case-management. Thanks to this approach, which was launched in 1991, 1,200 of the state's estimated 2,000 mentally ill homeless now have decent housing. The support services are necessary so people stay on medication, avoid crises, and begin to live ordered and stable lives. Often they become able to take paying jobs.

This initiative, a national model, has an 83 percent success rate, and it is surprisingly cheap. It costs only $3 million of state money to house and support another 200 mentally ill homeless people. In other words, for $12 million more the problem in Massachusetts would be solved.

Although this initiative was embraced by William Weld, the former Republican governor, his successor has been surprisingly unsympathetic. This past year the governor's budget included no money for the homeless mentally ill. The state Legislature added a million dollars. With next year's budget due in mid-January, Governor Cellucci is still considering whether to support any additional funding.

Nationally the picture is even less defensible.

Community living for people with disabilities of various kinds works; it is far more cost-effective than institutionalizing people who cherish their freedom, and far more humane than leaving them to push their worldly possessions in shopping carts and sleep on heating grates. Yet nationally, the public funding for community living initiatives has eroded dramatically in recent decades.

Side by side with the crisis of homelessness for the mentally ill is a shortage of housing for victims of abuse and for ordinary people of modest income who cannot afford spiraling rents. In the years after World War II, the economy boomed but housing stayed affordable because government subsidized its construction in a variety of ways.

In the 1990s, however, government essentially stopped adding new units of subsidized housing to the nation's housing stock. Especially in booming metropolitan areas, supply and demand took over and pushed rentals to unimagined levels. In this game of musical chairs, some people doubled up and some simply got pushed onto the street.

As I write, both political parties are debating what to do with an unprecedented federal budget surplus. Most Republicans want to spend much of the surplus on a tax cut. Most Democrats want to use it to pay off the national debt.

Both miss the point.

Looked at through a green eyeshade, the budget surplus is a mark of fiscal rectitude. But looked at with even a shred of humanity, the surplus is a national disgrace. It reflects money wrung out of budgets for needy people.

In times like these, we should be spending some of this money so people can literally afford a roof over their heads.

In 30 years, our national income has nearly doubled, but more people are homeless today than in 1970. Indeed, 2,000 years after the birth of Christ in a manger shamed and awed onlookers, some people don't even have the shelter of a manger.

Kip Tiernan, the remarkable founder of Rosie's Place, the Boston shelter for homeless women and children, likes to say that the proliferation of shelters is not a success but a sign of failure. At this Christmas season, please remember the needy, but let's remember, too, that individual charity is no substitute for sensible and humane national action.

Robert Kuttner is co-editor of The American Prospect. His column appears regularly in the Globe.

© Copyright 2000 Globe Newspaper Company

###