THE WORLD FROM...Cambridge, Mass.

HARVARD University professor Graham Allison gave several Soviet economists a sweat shirt with the words written on it (in Russian): "Just Do It." He, a few other academics from Harvard and Massachusetts Institute of Technology, and the six Soviet economists are trying to persuade Soviet leaders to act on reform, not just talk about it.

Mr. Allison, a former dean of the John F. Kennedy School of Government, says there is too much planning in the Soviet Union, too much preparation, too much utopianism.

The small group of Soviet and American economists or political scientists have high ambitions.

Over the past three weeks they have devised a plan, a "grand bargain" that would dramatically change the world if - a big "if accepted by the leaders of the Soviet Union and the Western industrial democracies. It would transform the Soviet Union into a democracy and a full-fledged market economy. It would commit the United States and the other six members of the Group of Seven industrialized nations to assist this transformation with both technical help and unspecified billions of dollars of financing.

The Soviet Union would become a "normal country, a civilized country," as some Soviet citizens put it, not a country driven by Marxist-Leninist ideology and pledged to world revolution.

Economists, of course, have had a major impact on world history. John Maynard Keynes, the famed British economist, wrote about the influence of "dead economists." Keynes, representing the British government, along with Harry Dexter White, a Harvard man and undersecretary of the US Treasury, and economist Edward Bernstein, were leading designers of the system of financial institutions - the International Monetary Fund, the World Bank, and, in a way, the General Agreement on Tariffs and Trade - which stem m

ed from the 1944 Bretton Woods conference and still help maintain the world economic order.

But none of Allison's group are in official positions of power. In this regard, notes Stanley Fischer, an MIT professor and one of those who drew up the inch-thick reform proposal, "This is certainly unusual. You tell me about another one like it."

The Soviet-US group, though, does have influence.

The head of the Soviet team, for example, is Grigory Yavlinsky, a former Russian deputy prime minister and author of a 500-day plan for Soviet economic reform that got nowhere.

Before his departure for Cambridge, he had the ear, approval, and some expense money from President Mikhail Gorbachev. He also presented the general proposal to President Bush earlier this month, who, Mr. Yavlinsky says, responded by saying, "I like what we heard."

Mr. Fischer was chief economist at the World Bank until last year. Harvard Professor Jeffrey Sachs is an adviser to Solidarity in Poland. Allison has been an adviser in Washington.

After giving a press conference with Allison at the Kennedy School here Friday, Yavlinsky returned to Moscow to present the plan to Mr. Gorbachev.

"We will see what will be his reaction," the genial, bushy-haired economist said.

Mr. Bush and the leaders of the other industrial nations will also be asked to consider the plan.

If all goes well, it could be discussed at the Group of Seven meeting, which starts in London on July 15 and which will receive Gorbachev on July 17. But, as Fischer admits, "This thing can fall off the rails."