While Uncle Sam turns his back on the problem, a growing number of states are turning their attention to the nation's glaring shortage of affordable housing. They may even have a money tree to provide billions of dollars to do the job.

*For starters, the New York Legislature, under Gov. Mario Cuomo's urging, appropriated $25 million in April for low-income housing construction and rehabilitation.

*California has just earmarked $20 million yearly from tidelands oil revenues for poor people's housing.

*New Jersey set aside $25 million this year: $15 million for lower-cost housing to help integrate suburbs and $10 million for urban projects.

Connecticut's Democratic Gov. William O'Neill says: "The ability of almost any citizen in this state to achieve what was once a customary standard of shelter is now fully open to doubt." O'Neill has just proposed a $183 million program of state-backed low-interest mortgages, rent subsidies, new construction and renovation.

You might mark that down as a liberal gesture. But Connecticut's Republican Senate majority leader, Reginald Smith, discounted the O'Neill proposal as nothing particularly new. He said Republican lawmakers would be looking for "some really creative" funding mechanism, including a possible tap on the state's real estate transfer tax.

The real estate industry turns almost apoplectic at the very thought. But taxing a minimal percentage of real estate transactions -- 1 percent or even less -- would enable states to mine this country's most speculative and dynamic private capital flow: real estate sales.

As real estate prices in most regions have ridden a fast-moving upward escalator, middle- to upper-class Americans have profited handsomely. But the inflated housing prices and interest rates have knocked many of their sons and daughters (not to mention poorer Americans) off the escalator completely.

A simple 1 percent transfer tax on one- to four-unit residential apartments in the Boston metropolitan area alone would yield at least $34 million a year, according to housing and neighborhoods expert Rolf Goetze. That doesn't even count the potential on land, office and commercial deals.

What could be fairer, or more appropriate, than channeling a tiny percentage of that capital flow to Americans who have been elbowed off the housing escalator? Members of the real estate industry fight the idea everywhere, but states and localities already have bored dozens of holes in the dike. Only 13 states lack some form of tax, however modest, on real estate transfers, escrow deposits, tenant security deposits and the like.

But bigger housing trust funds, funded through real estate transfers, are the new order of the day. Maine just passed such a bill. Florida, where the tax already is applied in Miami-Dade County, is set to consider the same next year.

"Within the next three years, we'll see the majority of states enacting or considering housing-trust-fund legislation," says David Paul Rosen, an Oakland, Calif.-based exponent of the concept.

Any new tax whips up heavy voter resistance these days. Siphoning off real estate dollars surely won't be an exception. A possible difference is that individual citizens don't buy and sell houses all that often, and thus wouldn't face the tax yearly as they do other levies. Earmarking some of the funds for middle-class housing could make it more politically palatable than low-income housing alone.

A bright spot is that scores of alternatives to traditional, subsidized housing are sprouting up around the nation. One example: The Minneapolis-St. Paul Family Housing Fund, initiated by the McKnight Foundation, has subsidized interest rates and down payments for almost 5,500 houses and apartments for low- to middle-income people, including first-time home buyers.

The Boston Housing Partnership is turning abandoned, tax-delinquent properties -- many technically owned by the Department of Housing and Urban Development -- into affordable housing for low- to moderate-income families. New York City's Housing Partnership Mortgage Corp., headed by David Rockefeller, has lined up seven insurance companies to invest a projected $50 million by year's end in new units and rehabilitated apartments.

As opposed to old-line subsidized programs, where city hall housing offices assign tenants, most of the new projects function through community development corporations that make sure the housing fits into neighborhoods and is well maintained and policed.

One promising model is approaching completion in Baltimore and due for a try soon on Manhattan's Lower East Side. It's called "mutual housing" -- an adaptation of a form of subsidized cooperative housing that's worked well in Germany since the 1890s. It is being introduced in America by Neighborhood Housing Services.

Mutual housing isn't cheap: Funds must be found to cover up-front construction costs. Association members make a down payment of a few thousand dollars and then cover maintenance costs monthly. They don't gain equity. But if they remain good neighbors, they -- and their children -- have lifetime rights to their units. The feeling of "ownership" is very great.

Lifetime housing security is very important for poor people, so often battered from pillar to post by hostile landlords, abandonment or gentrification. Another strength of mutual housing associations is that their boards include neighbors, business and government figures as well as tenants -- ideally a buffer against the "not in my backyard" attitudes that bedevil subsidized housing.

Given such promising new housing tools, it's easy to imagine how state housing agencies could perform incalculable service in administering big pools of real estate transfer-tax funds. That might keep the dream of decent, affordable housing alive for millions of more Americans. Of course some price must be paid. Don't we owe the poor -- and our own children -- as much?