Ask Federal Reserve Board Chairman Paul A. Volcker what he thinks about the job swap between Treasury Secretary Donald T. Regan and White House chief of staff James A. Baker III, and his response is as calm as if he were discussing the history of M1.

"I myself don't see why it should have any major policy effect," Volcker said last week. "I don't see any significance in it."

The same response was registered on Wall Street after the president announced the jobs switch last week: Trading that day was light, reflecting little emotion over the decision.

A week after President Reagan announced the change in jobs between two of his administration's most powerful advisers, it is still unclear what impact that decision will have on economic policy this year. Only Reagan, Regan and Baker know how the change will affect economic policy this year, and they are not yet talking.

Adding to the uncertainty over the executive-level changes will be new positions in the Senate for Sen. Robert J. Dole (R-Kan.), moving from the chairmanship of the Senate Finance Committee to become Senate Majority Leader, and Sen. Robert Packwood (R-Ore.), who takes over Dole's finance post.

Then, late last week, Reagan also nominated presidential assistant Richard Darman to the post of deputy Treasury secretary. Darman has served in five Cabinet departments during the Nixon and Ford administrations and once was an assistant secretary of Commerce.

Hanging in the balance because of these changes are the Treasury's tax simplification plan, budget and tax considerations, and the relationship between the president's new chief economic spokesman and the Fed.

In addition, as the finance minister of the world's most powerful economy, Baker will have to grapple immediately with the international debt problem, as well as with the spring meeting of the International Monetary Fund and the World Bank, and in May, the economic summit of industrial nations.

The views of Baker, a lawyer, on the domestic economy or international economics are not readily known; some administration insiders said his major problem may be in grasping international finance. However, on the domestic side, Baker is said to have been instrumental in negotiating many legislative compromises, such as on budget and tax-cut issues.

Baker will succeed Regan, who during 30 years on Wall Street rose to the top post at Merrill Lynch. Baker has not had wide experience on Wall Street or in the business world, but he has been director of the respected Texas Commerce Bank of Houston and also undersecretary of Commerce.

The move of Baker to Treasury is regarded by some financial analysts as a victory for pragmatism and traditional economic thinking, as opposed to the supply-side policies and constant optimism that emanated from Regan. For example, Baker -- like Dole -- has supported tax increases to reduce the federal budget deficit, despite oppostion to higher taxes by the president and Regan.

"Baker is a very thoughtful and experienced policy maker. I think he'll be excellent," said Alan Greenspan, chairman of the Council of Economic Advisers in the Ford administration and an adviser for the Reagan administration. "He's quite knowledgeable about financial and economic matters, and quite obviously is sensitive to the policy implications of what's going on," Greenspan said.

Regan, who is considered one of Reagan's strongest loyalists, has been criticized in private by his former colleagues on Wall Street for espousing any cause that would make the president look good. How he will fare amid the internal political wrangling within the White House has become a hot new riddle for official Washington.

But Regan brings with him tested organizational abilities and a drive to achieve what he sets out to do. He was a maverick in the financial world -- the first Wall Street chief executive to appreciate that brokerage firms could not survive much longer solely on income from trading stocks and bonds. He moved Merrill Lynch into ventures such as real estate and insurance, and the rest of the industry followed.

Another question mark is what role will be played by David Stockman, the president's director of the Office of Management and Budget, who also has privately pressed for tax increases and whose career took a nosedive when he criticized the president's economic policies in an Atlantic Monthly article in 1981.

Although Stockman has not said publicly that he will leave, some political analysts believe he will do so after the 1986 budget is completed. It also is uncertain who will be members of the Council of Economic Advisers, a group Regan is considering abolishing anyway.

Some analysts said the important alliance on the economic front may be between Baker and Dole, with greatly diminished roles for the OMB director and the CEA chairman, if one is selected. However, Regan's influence on economic policy still is expected to be strong.

For example, in an interview with reporters Friday, Regan talked as if he planned to maintain firm control of the Treasury Department's tax reform program his department worked on most of last year. Regan said final decisions on the plan will be presented to Congress after the budget is released next month.

Regan also reiterated to the reporters his wariness of critics of the tax reform proposal.

"If there's any sector of that plan that can be proven to us -- and that's the operative word, 'proven' to us -- that it will hurt a sector of the economy, or the economy as a whole, we would be willing to talk change," Regan said. "Now, there've been a lot of people complain about certain sectors, but no one yet has demonstrated the proof."

Regan already had begun negotiating with influential members of Capitol Hill to reach a compromise that will be enacted possibly by this summer, a job expected to be taken over by Baker.

Baker is not known to be opposed to a tax reform plan, and many analysts expect that Baker and Regan will support whatever proposal the president agrees to.

Regan also said that although budget deficits are the nation's number one problem, he still adheres to his long-held belief that budget deficits do not lead to high interest rates.

"If we can cut that budget deficit, I think we'll be rewarded with lower rates of interest than we would otherwise have," Regan told reporters. He said that interest rates would decline not because of any direct link between rates and deficits, but because there is a perception in financial markets that such a connection exists. "And if we do get that combination of lower rates of interest and the like, I think you'll find that part of our trade deficit will be cut back also."

Perhaps one of the biggest changes in the Baker-Regan exchange will be in style. Regan, whose administration has been characterized by brash statements and abrasiveness with the president's other economic advisers, is expected to be replaced by a more gentlemanly demeanor in Baker.

Regan on many occasions publicly criticized the antiinflationary monetary policies of the Federal Reserve as threatening the economic expansion, and last month he revealed that the administration was considering eliminating the Fed's independence.

Regan also has often sparred publicly with former Council of Economic Advisers Chairman Martin S. Feldstein, who campaigned that the deficits threatened the stability of the economy. When asked about Feldstein's 1984 economic report to the president, Regan made headlines for saying: "As far as I'm concerned, you can throw it away."

Regan has been one of the administration's most vocal "Fed-bashers," criticizing the Fed whenever he believed monetary policy was too stringent to keep the economic expansion going.

When Volcker was asked whether he was glad that Baker was replacing Regan so that Regan would get off his back, Volcker only smiled and said, "I didn't know he was on my back.