It was "John Who?" when the campaign began. The candidate asked the question himself in the headline of his New Hampshire newspaper ads as he struggled to make voters notice his long-shot candidacy.

John B. Anderson is no longer a curiosity piece in the 1980 presidential campaign. But the question arises again in a different way now, as the Illinois congressman prepares to run as an independent in the November election, opposing both the Republican and Democratic nominees.

Who is John Anderson and what are his views on the economy?

The difficulty with the definition is that Anderson is the man in the middle in 1980, somewhere left of Ronald Reagan and George Bush, somewhere right of Edward M. Kennedy and Jimmy Carter. There is no simple label that fixes the position, particularly on economic issues.

Anderson has built his success so far around what he calls "the Anderson Difference" -- a willingness to take firm, sharp stands on such controversial questions as gasoline taxes and gun control (which he favors) and the MX missile system (which he opposes). Paradoxically, his position on the economy is not as distinct, because it consists of a complex mixture of orthodox Republican conservatism and liberal activism.

The Republican right wing has long attached Anderson as a dangerous turncoat. Now the left has begun to challenge his right to liberal support. An article in the current issue of Rolling Stone magazine observes, "It's been said of Anderson that he brings to mind Wendell Willkie, the Midwestern moderate Republican nominee against Franklin D. Roosevelt in 1940. But in fact an analogy with William H. Taft may be more apt."

Anderson, to begin with, has never claimed to be a liberal as that label is applied on economic issues in Congress.

"I basically am a disciple of the free market system," Anderson said in an interview in his suburban Maryland home. The government cannot substitute its judgments "for the millions of decisions that have to be made daily by those who buy and sell," he added.

The litmus test of that perspective in recent years has been the debate over deregulation of interstate natural gas prices. When other energy prices took off after the 1973 Arab oil embargo, the price that natural gas producers received remained fixed by a 20-year-old federal regulatory program, rising only gradually. Liberals were determined to maintain regulation to protect consumers and limit energy producer profits.

Anderson stood with other Republicans and Democrats from gas-producing states who fought for deregulation of gas prices in 1977 and 1978. The result was a compromise that continues regulation until 1985, but permits a steady price escalation. Anderson supports the upward trend, saying that higher energy prices are essential to promote conservation and reward greater exploration for new supplies.

Stewart Mott, the financier of liberal causes, poured a small fortune into the fight against deregulation. Today, he is one of Amderson's important financial supporters.

Anderson describes himself as an "orthodox" Republican on economic issues. He has sponsored legislation that would limit federal spending to 20 percent of the gross national product, to control the size of government. With other Republicans, he criticized Carter for failing to offer a balanced budget for the 1981 fiscal year, and proposed 37 specific spending reductions totaling $11.3 billion to do the job. When the president and the Democratic congressional leadership moved to the same position last month, Anderson could claim "I told you so."

"Carter always seems to be on the trailing edge of economic developments," Anderson said.

Anderson's stand on tax policy also is essentially Republican. Just as he favored higher oil prices to prompt more drilling, he supports higher industrial profits to reward greater business investment in modernization, he says.

He calls for a two-percentage point reduction in corporate taxes by 1986, and backs the business community's No. 1 tax objective, a change in depreciation rules to permit a much faster write-off for buildings, equipment and vehicles (thus reducing corporate taxes and increasing available cash. He also backs proposals to protect taxpayers by automatically adjusting (indexing) rates downward as wages rise due to inflation.

A measure of "orthodoxy" is the political ratings by the liberal Americans for Democratic Action and the conservative Americans for Constitutional Action (although economic issues are only one set of key votes the two groups scrutinize).

Anderson's ACA rating was a near perfect 91 in 1965, the year after the 1964 presidential race when he supported Barry Goldwater, the conservative Republican nominee. His ADA rating that year was 11.

In the 1970s, however, Anderson's liberal score from ADA had moved up to a 40-50 range, while his conservative ACA rating dropped to an average of 46.

This shift does not mark a defection from Republican economic principles, Anderson says, and the record bears him out.He moved left essentially on social and foreign policy issues. "My heart is on the left and my pocketbook is on the right," he says frequently.

But if he is not an economic liberal, he also is not a pure free-marketer, whose only goal is getting government off the back of private business. He parts company with both Kennedy and Reagan, for instance, on overall energy policy.

Kennedy is wrong to think that the federal government can manage the nation's energy problems efficiently, Anderson said. "He just doesn't have any faith in the free market system at all," the congressman said But Reagan also is misguided in wanting to abolish the Energy Department and let the energy companies run free, he added.

"I think the government has to be more than just an indifferent spectator at ringside. It has to be more of an umpire, an arbiter and represent the public interest," he said.

Where Reagan would dismantle many federal laws that regulate business and the economy, Anderson says the laws and regulations must be changed to solve the nation's major problems.

It is this drive to change and reform government, and to have the government set goals and priorities for the country that separates Anderson from many of his Republican colleagues.

That is the essence of the ideas that garnish Anderson's speeches -- of a "social contract" between government, business and labor, of an "incomes policy" to restrain wage and price increases, of a "temporary national economic commission" of prominent citizens formed immediately after the 1980 election to consider answers to the nation's economic problems.

Such a commission could "outline precise goals and targets" on behalf of the administration. The goals would be something concrete that business could base their plans on, Anderson said, a sharp change from the "seat-of-the pants" economic policies he says the Carter administration has followed.

While Anderson favors substantial tax reduction for business, he is unwilling to do it with no strings attached, as Reagan would, he says. "I really believe in a much more planned, targeted approach." Anderson said. "Now when you mention 'planning,' that really raises the hackles on the backs of some people's necks. It suggests a detailed economic plan and that's not what I really mean." He means goals -- an attempt at reaching a broad consensus among business, labor, and the economy's competing interest.

"I've talked about a national unity administration, with a fairly eclectic group of advisers. I'm not the captive of any single school . . . I would try to demonstrate a willingness to consult with a broad group within the country -- that alone would restore the confidence that has been lacking (in economic policy).

"I think we ought to have a kind of social contract that, if government did its share to reduce spending and stabilize the economy, we could reasonably call on business and labor to show restraint" in price and wage increase, Anderson said.

Anderson's interest in a negotiated economic consensus is being encouraged by one of the country's master bargainers, Felix G. Rohatyn, a New York City banker and chairman of the city's Municipal Assistance Corp., the private financial group formed in 1975 to help New York avoid bankruptcy.

Rohatyn contends that the country is sliding toward bankruptcy as surely as New York City did five years ago and only a temporary freeze on wages and prices and other drastic measures will keep the country from an economic emergency. Weeks before the New Hampshire primary, Rohatyn was describing Anderson as the only candidate whose proposals were bold enough for the times. He particularly liked Anderson's plan for a 50-cents-a-gallon tax on gasoline, to enforce fuel conservation and limit U.S. imports of foreign oil.

Rohatyn, a Democrat, is one of those whose economic advice Anderson listens to closely, he says. He also consults with Michael K. Evans, a business-oriented economist.

Anderson is not an overnight convert to economic goals and national agreements between business and labor on wage and price policy. Nine years ago, during an earlier siege of double-digit inflation, he was one of a very few Republicans calling for such an incomes policy.

He supported the Humphrey-Hawkins bill, a symbolic commitment to full employment sponsored by the Democratic New Deal coaltion. His current, longer-range proposal for wage and price restraint is a tax-based incentive program (TIP) patterned after the proposal by the late Arthur M. Okun, chief economic adviser in the Johnson administration. The TIP approach provides tax breaks for companies that meet wage and price guidelines, while raising taxes on those that don't comply.

The support for TIP, too, is the mark of an activist who says political leaders are elected to find answers to national problems, not stand by. His major legislative achievements involve compromise measures on protection of Alaskan lands and campaign spending reforms, worked out with Democratic liberals in the House.

Where social and economic problems criss-cross, Anderson is a political moderate, favoring a balancing of interests. "I just think government has to speak up for the dispossessed and the disadvantaged. There are a lot of social goals that are not going to be met if you sit back and rely on the unfettered operation of the market system," Anderson said.

Responding to the powerful attack by business against government regulation, Anderson opposed establishment of a separate Consumer Protection Agency, and supported the first of many efforts to limit the consumer protection actions of the Federal Trade Commission. He hasn't gone all the way, however, with the Ftc's severest critics.

"I think the brouhaha over regulation has had a therapeutic, a deterrent effect. Generally speaking, federal administrators and regulators have been a little more cautious" lately, he said.

Anderson thinks the Carter administration has struck a reasonable balance between the competing pressures of trade policy, giving some protection to industries like steel, threatened by foreign imports, while resisting a general drift toward such trade restrictions.

Anderson acknowledged that balancing conflicting social and economic interests becomes tougher as the economic problems grow. There aren't many dividends in a balanced budget to spread around.

He has said that the federal budget should not be balanced "on the backs of the poor," and would trim more from the 1981 Defense Department budget that most of his Republican colleagues would accept. But Anderson's proposed budget cuts would affect some recipients of federal aid. The annual increase in federal pensions, for example, would be cut by $3.5 billion under Anderson's proposal.

He would increase government aid for casualties of a recession. "I think we're going to have to maintain income support programs to make sure that people who are out of work do not suffer," he said. But he would resist an early move to revive the economy as soon as unemployment begins to climb.

"I don't think I could recommend a tax cut in 1980, given the inflationary problems and the impact a tax cut would have on them," he said. His first priority is reducing inflation. Once confidence in the economy had been restored, and the public was convinced the government was really leading the charge against inflation, then it would be time for tax cuts to stimulate business investment and reforms to ease the tax load on individuals, he said.