(FORTUNE Magazine) – ''The single greatest problem of the U.S. economy in the late 1980s is its extremely low level of national saving,'' assert the authors of Overconsumption: The Challenge to U.S. Economic Policy. Fair enough. The paper, published by the American Business Conference, offers two unusual solutions plus a provocative argument that debt-financed takeovers and buyouts have made the problem worse.

Overconsumption's authors include two MIT economists, Paul R. Krugman and James M. Poterba, and George N. Hatsopoulos, who is chairman of the Boston Federal Reserve and also of Thermo Electron Corp. (see ''Growing Fast on the 500's Fringe''), which helped underwrite the study. The authors want to get the U.S. saving rate above the 8% level of the Seventies. They acknowledge that the federal budget deficit is a serious impediment but rightly emphasize that the shrinkage of private saving has been an even bigger drag. IRAs failed, they say, not only because the program was too short-lived but also because it attracted mainly high-income people and didn't offer them enough shelter. Hatsopoulos, Krugman, and Poterba propose instead that the Treasury issue seven-year, zero-coupon ''supersavings'' bonds carrying above- market interest rates. These would be available only through monthly payroll deductions with a cap of $5,000 per worker each year, and savers would not be taxed until they redeemed the bonds -- which could be rolled over indefinitely. The costs to the Treasury would have to be offset by cuts elsewhere in the budget. Since incentive alone may not suffice, the new bonds must be promoted heavily: ''A campaign to raise saving is at least as important as the actual instrument.'' Companies should tout them to employees as they do, say, the United Way. Would jawboning work? The authors note that it raised Japan's saving rate dramatically after World War II, and in the U.S. more recently helped curb energy consumption and reduce highway fatalities. Even if the campaign succeeded at first, though, the long run could be a disappointment if the holders took a beating from higher inflation or interest rates. The proposal for corporations, which is more radical, aims at the unequal taxation of equity and debt. Hatsopoulos, Krugman, and Poterba would put them on an equal tax footing by replacing the current deduction for interest payments with a credit equal to 5% of both equity and debt, a method they figure would generate the same revenue as the current system. They grant that 5% is arbitrary, but no more so than the deduction of interest payments alone. They also acknowledge that the change would be hugely complicated, requiring detailed transition rules to avoid disrupting capital spending. Would Congress go along? The proposal offers an interesting correction of the tax system's tilt toward debt, but Capitol Hill has little appetite for making big changes in the code. The paper's most provocative conclusion might provide an extra incentive for the many congressional critics of takeovers financed by debt. The authors calculate that stockholders who received cash payouts from takeovers and buyouts in recent years have spent more than half their gains -- far more than such presumably wealthy investors would be expected to. In 1987, they say, such spending accounted for a decline of 0.8% in the personal saving rate. Though any such estimate is imprecise at best, the authors' work does suggest that the impact on savings is significant.