The names John Lichtblau, Arvid F. Jouppi or John A. Schnittker may not be household words to most Americans, but don't be surprised if you think you've heard them somewhere before.

Although none is a politician or celebrity, all are frequently quoted in the nation's leading newspapers, magazines and TV programs, from The Wall Street Journal and Business Week to the "MacNeil-Lehrer Report" on PBS.

More importantly, what these people say often sways millions of dollars in both business and government decisions. Pronouncements by Henry Kaufman, a financial expert, regularly send the stock and bond markets into spasms.

These are some of the men and women who have made reputations as modern-day "mavens" -- experts in particular fields or industries, whose views are so widely quoted that the experts have become institutions in their own right.

To most outside observers, Kaufman probably is the most influential. His warnings about a possible collapse of the bond market last winter were a key factor prompting President Carter to announce a major new economic package March 14, designed in part to sooth those very jitters.

But others also are widely respected: for example, Lichtblau on petroleum and energy, Jouppi on the auto industry, Michael Sumichrast on housing construction and Schnittker on agricultural issues -- to name a few.

Another analyst, John Morton, is a nationally recognized expert on the newspaper industry. And New York securities specialist James E. Sinclair is quoted widely on the gold market and sales of strategic metals.

There are dozens of others whose names turn up regularly.

Who are these American mavens, and how did they get where they are today? How good are their track records? And more importantly, what is really their role in today's society?

It's 4:48 p.m. on a wintry Thursday, and a Washington correspondent for a large metropolitan daily newspaper has just returned from a White House briefing announcing a new U.S. embargo on grain sales to the Soviet Union.

Under pressure to complete a news story on the new action by 6 p.m., she calls an Agriculture Department official to check on one aspect of the announcement and shuffles through her files for some recent clips.

Then, still uncertain about the proposal's real impact, she phones an outside expert for some help. On the other end of the line, in a cluttered office atop a Georgetown bank, John Schnittker picks up his phone.

Schnittker, a soft-spoken man of 56 who was undersecretary of Agriculture during the Johnson administration, already knows most of the details of the new embargo and has made an initial assessment.

Quickly and succinctly, he proffers an estimate of its impact on supplies and prices and points to a potential snag that the White House briefer hadn't mentioned.

Then Schnittker provides a few more perspectives "on background" -- that is, with the agreement that what he says on these points won't be attributed to him in print. Eleven minutes later, the reporter has what she needs in order to write.

The article in the next day's paper has far more perspective than it otherwise would have had, with assessments from "other sources" balancing off the official White House rhetoric. On one issue, Schnittker is quoted directly.

It's a fair-seeming trade: The reporter, whose expertise on the complexities of grain embargoes doubtless is limited, gets some help from a knowledgeable -- and accessible -- source she knows has no political ax to grind.

Schnittker, who may or may not get his name in the paper as a result, influences what is printed, gleans from the reporter's questions what others are thinking and broadens his own impact.

For Schnittker -- as well as for other widely quoted mavens -- talking to reporters is only a small part of the daily routine. All are full-time consultants or analysts working for themselves or well-known firms.

Kaufman, for example, is a partner and chief economist in Salomon Brothers, a prestigious New York investment house. Jouppi works part-time for John Muir & Company, a securities firm, and runs his own consulting business from Detroit.

Morton is based in Washington, also for John Muir & Company, while Sinclair heads his own securities and investment firms in New York. Schnittker is a full-time agricultural consultant.

Their clients, collectively, range from banks and insurance companies to manufacturers and foreign governments -- from grain companies to investors. Like the journalists, all want advice and information. Lichtblau and Sumichrast serve a different clientele: Both work for industry-related groups -- Lichtblau for the Petroleum Industry Research Foundation, sponsored by oil firms, and Sumichrast for the National Association of Home Builders.

In all these cases, such connections naturally give rise to potential conflict-of-interest questions. Can an analyst use the information he may get, say, to make a killing on the market?

And how far should newspaper readers trust the assessment of an analyst who's employed by an industry group? Won't he inevitably be biased toward his industry's point of view?

Both the mavens and reporters insist, fairly convincingly, that in most instances, these don't pose a serious problem.

In most cases, the analysts are in business to obtain information, not to trade in the markets or promote new products, and they most likely already are aware of whatever new developments a reporter is asking about.

And Lichtblau and Sumichrast, to name two industry-related analysts in particular, have demonstrated over the years they take pains to avoid seeming to be shills for their individual industries.

"Once you get labeled as an industry spokesman, you're very, very limited," Lichblau cautions. Snaps Sumichrast: "I take the position that I don't have to work here. My strength is to be as honest as I can."

How does an ordinary industry expert get to be a maven? Most often, it happens accidentally: A crisis develops, and it turns into a major news story. All of a sudden, the analyst finds himself widely quoted.

For Lichtblau, the break came predictably with the start of the Arab oil embargo, in 1973. "Before that, oil wasn't all that important," he recalls. "Suddenly, it came, and reporters needed information -- in a hurry."

Kaufman's popularity with reporters began in the mid-1960s, when he began writing a weekly newsletter on the financial markets called "Comments on Credit." His style was so clear and crisp, he seemed a natural to call.

Once the ice is broken -- say, a name turns up a time or two in Business Week or The Wall Street Journal -- the journalistic herd instinct takes hold, and other publications, and eventually the TV networks, seem to follow.

"There's a little bit of snowball effect," Sinclair notes. "The more often they quote you, the more you become an expert, and the more you become an expert, the more often you're quoted."

Predictably, some would-be mavens mount full-fledged campaigns in an attempt to get their names in the paper. Sinclair, for example, hired a full-time press agent to help him break into public print.

Sinclair excepted, however, such efforts usually backfire. "And, while some analysts continue to be quoted widely for years, others find their phones soon go silent -- either because they've been replaced by fresher, newly fashionable experts or simply because of changing circumstances.

Why do some analysts turn up in print repeatedly, while others rarely appear at all? According to both the mavens and the reporters who cover them, the most quoted analysts share three basic characteristics:

First, they're all reasonalby accessible -- available to answer the phone on short notice, particularly if a reporter is facing a tight deadline.

Second, they're conscientiously honest -- able to take a broader, more policy-oriented view, rather than just promoting their own clients' interests -- and articulate as well.

As Schnittker puts it: "We try not to display our feelings or biases, but when we do, we make them known. We do not ever, if we can avoid it, push a point of view that isn't backed up by some kind of analysis."

And finally, they're extremely knowledgeable about their subject matter. "You've got to know what you're talking about -- or simply don't say it," Morton warns.

As might be expected, the mavens haven't been infallible, Jouppi, for example, recalls forecasting through the mid-1960s that General Motors stock would soar to $200 a share -- only to see it plunge after hitting $113.

Schnittker blushingly remembers advising clients a few years ago that U.S. farmers would not step up their soybean planting -- no matter what other analysts were saying. As it turned out, they did -- by a hefty 7 percent.

And in 1978, Lichblau put together a report on the outlook for world oil supplies that barely mentioned the posibility of an Iraqi-Irani war. "If you take what we have in retrospect, it looks silly," he says sheepishly.

Obviously, one wrong call won't ruin a maven's chances of being quoted again. But a string of them inevitably will sour journalists. And misleading a reporter once inevitably will turn him off.

Expectedly, the analysts' pronouncements quite often draw fire -- even if they're on target. Lee Iacocca, chairman of the Chrysler Corporation, recently groused that bad-mouthing by industry analysts hurt car sales early this year.

And some mavens find their own clients sometimes get upset if the analyst's views are aired in the press before they're send to the consultant's paid subscribers.

Schnittker has a rule-of-thumb to minimize that conflict: "If a reporter happens to call us before we've talked with our clients, we'll discuss an issue with him," he says, "but we try to phone our clients that very night."

By their own reckoning, the seven got into their respective specialities in a variety of ways:

Sinclair, an intense man who's just turning 40, claims he was born with a ticker tape in his mouth: His father sold securities on New York's curbside stock exchange in 1912, and Sinclair followed in the family business. c

His career hit a turning point in 1977 when Sinclair formed his own firm. Since then, he's branched out into cable TV and trading of metals. "Ever since I've been a kid," he says, "I've had no real goal outside this industry."

Jouppi, a disarming, jolly man of 62, is a would-be engineer who got involved in auto-industry finances because it seemed a quick way up the corporate ladder when he worked at General Motors in the early 1950s.

Kaufman started out to be a chemist or physician, but found college chemistry too complex -- and settled for economics as a substitute. A former economist for the New York Fed, he joined Salomon Brothers in 1962.

Hard-driving prim and serious-minded, he finds little time for recreation. Q: What do you do to relax? Kaufman: "I work." Lichblau, 58, also a perfectionist, is a Vienna-born economist who got into the oil business "mainly by accident": He was working in Washington at the Labor Department when a friend steered him to a job in an oil-consulting firm.

Sumichrast, 58, started as a sportswriter in his native Czechoslovakia, got into construction work after fleeing to Austrailia and branched into economics after arriving -- penniless -- in the United States. He has been with NAHB since 1963.

Morton, 46, is a former newspaper man who made good. A one-time reporter for the now defunct National Observer, he became an industry analyst in the early 1970s. [TEXT OMITTED FROM SOURCE] variably have some things is common: All do a lot of reading -- and traveling -- to keep up with new developments in their fields. All love to talk about their interest areas. And all put in relatively long hours.

After a start-of-day briefing on European currency markets, Sinclair makes a quick check of the firm's foreign and domestic branch offices, works on reports and client advisories and goes over market changes throughout the day.

"We let the younger kids run the night operation," he says. "I used to do this myself, but I ran out of steam."

Jouppi spends Mondays in New York, but operates out of Detroit-proximate Grosse Point, Mich., the rest of the week. Lichtblau comes in at 9 or 9:30 in the morning, leaves at 7 or 8 at night.

What does a maven get out of all the time spent on reporters? Most insist the publicity doesn't bring in substantial numbers of new clients. But there are some returns: The analysts say they sometimes pick up new information just from a journalist's questions. And the exposure in print gives them heightened access to the contacts they want to reach.

Sincliar concedes frankly he's also hoping his continual exposure will help thrust him into a policymaking job some day -- possibly undersecretary of the Treasury for monetary affairs. But other mavens are not that ambitious.

Except for Morton, who foresees relative prosperity for the newspaper industry next year, virtually all of the mavens are pessimistic.