Abel Aganbegyan, a top Soviet economist close to Mikhail Gorbachev, shrugs and cites an old Russian proverb: "The pessimists say it's not possible for it to get worse. The optimists say that it is possible."

"It," of course, is the Soviet economy. In a conversation with Post reporters the other day, Aganbegyan said that not only is the Soviet Union suffering from hyper-inflation but that the budget deficit during Gorbachev's attempted reforms had zoomed from $10 billion, or 1 1/2 percent of gross domestic product in 1985, to a staggering $90 billion, or 10 percent of GDP in 1989.

As a result of what could be an imminent collapse of the Soviet Union -- even anarchy or civil war -- President Bush increasingly is being urged to retreat from the cautious stance he took for aid to the Soviet Union at the Houston economic summit in July. There he promised Gorbachev only technical and managerial assistance pending completion of a study of the Soviet economy by the International Monetary Fund.

Bush's rationale, not to be dismissed out of hand, was that giving money to the Soviets was like pouring money down the drain. Aganbegyan doesn't deny the incredible inefficiency of the Soviet system, one that has succeeded in emptying shelves in the shops and markets.

Even with a new harvest that Aganbegyan says is a record, the Russian food crisis has worsened because farmers unsure of the next turn of political events are hoarding grain supplies on the farm.

If the Soviet Union is to exist at all -- if Bush wants to preserve an effective central government in Moscow that might yet endorse Bush's increasingly warlike stance in the Persian Gulf -- he must rethink the Houston policy, and quickly.

At a minimum, the Soviet Union desperately needs emergency food help this winter, as Gorbachev himself made painfully clear last week in Paris. In particular, the Bush administration and the European Community would do well to consider an imaginative proposal to use the Common Market's food surpluses to feed the Soviet multitudes.

Jagdish Bhagwati of the Russell Sage Foundation and Padma Desai of Columbia University -- a husband-and-wife team -- have dreamed up this idea, stunning in its simplicity: The Europeans have too much food because over the years they have subsidized their farmers. And the Russians are hungry.

Why not, ask Bhagwati and Desai, provide a temporary market for European food surpluses while the subsidies that create them are scheduled to be trimmed by the Uruguay round of trade negotiations? That would cushion the adjustment for European farmers that is proving to be politically difficult, especially in France and Germany.

Bhagwati, who is a trade expert, and Desai, who has written extensively on perestroika, propose that Europe grant the Soviets long-term credits to repay European farmers. They suggest that after five years, this could be done in convertible currencies for 20 million tons of foodstuffs annually.

Since the European surpluses would be rationed at fixed prices in state stores in the cities, the additional supply would help deflate farmers' hopes of price increases that now stimulate hoarding, Bhagwati and Desai said in an interview.

Beyond food, there is the question of overall aid to the Soviet Union. Sen. Sam Nunn (D-Ga.) has urged a waiver of the Jackson-Vanik Amendment, which bars the Soviets from most-favored-nation status. "Chaos in a nation that possesses 10,000 nuclear weapons is not in our national security interests," Nunn says.

That concern is outlined in detail in a new study by Timothy W. Stanley, president of the International Economics Study Institute, a nonprofit Washington research group. Stanley calls on Bush to be a more aggressive participant, along with Germany, in offering both bilateral and multilateral economic assistance to the Soviet Union: "Beyond technical advice, the United States needs to put some money where its mouth is to help the Soviet transition to a functioning market economy."

Stanley fears that, without a big boost from Washington, the Soviet Union might not only lose control over its nuclear weapons but suffer serious consequences that could be harmful to Western and world interests. Among them: a reversion to old or orthodox Soviet thinking, or even civil war and a breakup of the Soviet Union into multiple parts.

The real issue is not the amount of aid or credits that the United States can afford in its present budgetary straits, but the political symbolism involved. If perestroika fails, it should not be seen as the result of Western refusal to heed the cry for help. The United States also has a selfish stake "in being in on the ground floor" after spending $4 trillion to contain the evil empire, Stanley says.

The next few months could make or break both perestroika and Gorbachev. If Bush wants help from Moscow, instead of the dangers that might arise from a total collapse of the Soviet Union, this is the time to act.