Washington — A touch of good news brightens the economic picture at least slightly, with word that sky-high interest rates may have begun to edge down. A key White House official reacted cautiously to news that the Chase Manhattan Bank has lowered its prime rate half a percentage point to 20 percent.
"Obviously it is a welcome development," said Murray L. Weidenbaum, chairman of the Council of Economic Advisers (CEA) in a telephone interview, "but the term 'high interest rates' still applies."
Interest rates stuck at near historic highs trouble the White House because they appear to reflect widespread doubt among money managers that President Reagan's economic program will work.
Specifically, a balanced budget by 1984 -- the President's firm pledge -- seems to many analysts to be beyond Mr. Reagan's grasp.
Evidence that the 1982 budget deficit may end up in the $60 billion range, rather than the $42.5 billion aimed at by the White House, has continued to prop up interest rates, particularly in the eyes of Wall Street.
viewed more broadly, high interest rates have thrown at leat two key industries -- housing and autos -- into a slump and generally have slowed the economy to a crawl.
The stock and bond markets have tabogganed down, as investors deserted shares in favor of quick returns on their money in money-market certificates of various kinds.
At this writing, the stock market was up slightly, though it was too early to know whether this forecast some recovery for the Dow Jones industrial average.
"Quite clearly," Mr. Weidenbaum told reporters at a Aug. 31 breakfast meeting with reporters, "the [financial] market if taking its time to adjust to a less inflationary climate.
"Investors," he added, "have been burned many times in the past. So a certain amount of skepticism is understandable."
Several factors, all revolving around uncertainty about the future, appear to impel financial managers to keep interest rates high:
* Burgeoning federal deficits would force the US Treasury to increase its borrowings, thereby putting a squeeze on available capital.
* Despite some lessening of inflationary pressure, many analysts seem to believe that inflation will remain a stubborn problem.
* The Federal Reserved Board, under chairman Paul A. Volcker, vows to keep a tight rein on the money supply until inflation is more clearly under control.
apparently Chase Manhattan lowered its prime -- the rate of interest charged to its most credit-worthy customers -- in response to a slight easing ot other, mostly short-term, rates.
The interest which banks charge each other on overnight loans, for example -- called the federal funds rate -- has declined more than two percentage points in recent days.
Experts caution that none of this portedns a sustained fall in interest rates generally, until the future of federal budget deficits and inflation becomes more clear.
Pressure remains heavy on the Reagan team to find additional ways to trim the 1982 budget, both to fulfill the President's deficit pledge and to inject some confidence into the financial markets.
"We are mindful of the fact," said Weidenbaum, "that the more we can reduce the budget deficit, the healthier the response of the markets will be."
With many federal programs already cut to the bone, where will White House officials find additional billions?
Currently the Pentagon's vast budget is in the budget-cutter's sights, and the White House appears to be laying the groundwork for trims in defense outlays.
"How much defense can we afford?" asked Weidenbaum. "We can afford what we need."
But, he added, "there is a serious technical question. How fast can you feasibly expand military spending?"
Can the Pentagon, in other words, really use all the extra money for defense contained in President Reagan's 1982 budget?
"From fiscal 1980 to 1982," said Weidenbaum, "There is a 55 percent increase in defense spending authority. From fiscal 1980 to 1984 the increase is over 100 percent."
As a "management question," says the CEA chief, "we need always to consider the optimal efficient rate of absorption."
This appears to be a way of saying that, on grounds of efficiency, defense spending -- currently designed to consume $1.5 trillion over five years -- might be stretched out, without violating the President's pledge to boost defense outlays by 7 percent annually in real terms.