You can find Amitai Etzioni at the White House now, which is an appropriate address for a man Time magazine once labeled "the everything expert."

Etzioni is a sociologist concerned with the conduct of public policy, a rare bird in White House political circles where social scientists have yet to achieve the clout of economists and lawyers. But in the last two decades, Columbia University professor Etzioni studied such subjects as genetics, nursing homes, politics, gun control, families, income tax, status, Vietnam, the space race . . . the list of topics considered by Etzioni and the Center for Policy Research he founded in 1968 is boggling.

Reporters wondering about the meaning of the width of men's ties and politicians (such as Nelson Rockefeller) seeking counsel know a call to Etzioni will elicit a quick opinion that might fly wonderfully in the face of conventional wisdom.

Last July, just after Jimmy Carter delivered his speech about energy self-sufficiency and the crisis of the American spirit, Etzioni was hired by Richard Harden, President Carter's special assistant for information management and director of the office of administration.

"His task is not so much to say, 'Here's a solution,' but to say, 'Here's where some people are who are knowledgeable in this area,'" says boss Harden. The White House's Mr. Information has devoted time to energy problems, inflation, unemployment and how to use the world's information explosion.

Etzioni -- perhaps aware that in the past his high visibility has drawn fire from colleagues who branded him a glory seeker -- would rather not discuss specific tasks. But he will reflect on his current thinking about America, a subject he considered for a year as a Brookings Institution guest scholar prior to his move to the White House.

"Behind America's specific problems such as inflation, energy and the decline in productivity," says Etzioni, "is a loss of productive capacity, both economically and psychologically. That includes the loss of will to work hard and to save hard. I characterize the United States as an underdeveloped nation, and I mean it technically;

"We have the lowest rate of savings of any industrial nation. Our inflation rate almost matches Mexico's. We have a decline in productivity for the first time, and the rate of research and development is declining. The railroads are coming apart, even the highways and bridges. It's not going to all collapse; it's just an erosion process.

"I think that if we want to go on to be a major international power, and if we want to continue to have a high standard of living, we must spend a decade investing and shoring up the country's productive capacity."

Etzioni thinks Carter and America are ready for that, a view that fits nicely with an observation the sociologist made in the late '60s: to manipulate a complex social organization, one must first achieve a popular consensus, then link it to a well-established power base.

Etzioni talks faster than Henry Kissinger, but his accent resembles that of the former secretary of state. (The similarity ends there; Etzioni began publicly criticizing the war in Vietnam in 1964.) Born in 1929 in Cologne, he fled with his parents seven years later to Palestine. As a young commando, he fought the British and later the Arabs before traveling in 1957 to the University of California at Berkeley where, 18 months later, he received his Ph.D. He is married and has five sons.

Etzioni will leave the White House in July to become George Washington University's first "university professor," where he'll be comfortably close to the corridors of power.

"One of my fondest memories," Etzioni says, "is of the president's staff sitting on the floor of Hamilton Jordan's office the night the president gave his speech.Hamilton was adjusting the dials on the set so the image of the president would come across more clearly and in better color. I thought that was sort of symbolic."

If it's also prophetic, it's a good bet that at the White House in the first half of the '80s, the peripatetic doctor will be in.