At first glance, Treasury Secretary James A. Baker III appeared to have made a major gain yesterday in his efforts to buoy the world economy.

The decision yesterday by seven European central banks to lower key interest ratescapped a 10-day period during which European governments announced a steady stream of fiscal and monetary measures aimed at spurring economic growth. The actions, which Baker strongly urged, raised hopes that the Treasury chief will soon engineer an international agreement designed to check the dollar's precipitous fall, hold down interest rates and avert worldwide recession.

Such an agreement, in turn, could bolster Baker's hopes of keeping the economy afloat during the 1988 election campaign, with obvious benefits for the Republican side.

But many economists caution that Baker's initiatives won't fundamentally alter the global economy's underlying problems. In their view, Baker appears to be obtaining only modest progress toward shrinking the huge U.S. budget and trade deficits and the need to borrow vast sums of money from abroad.

And as yesterday's steep stock market decline makes plain, Baker's efforts may not be enough to ward off new waves of pessimism in financial markets in the months ahead.

Baker's efforts are "too little, too late" to gain meaningful reductions in the twin deficits, said John Albertine, an economist and vice chairman of Farley Industries, a diversified company. "The $64 dollar question is, can he get to November '88? I'd say there is a 50-50 chance that he can patch together enough {policy actions} to eke it out."

Stephen Roach, senior economist at Morgan Stanley & Co., agreed. "Right now," he said, "the approach of policy is one of patchwork, and one that basically has a 14-month time horizon."

Roach contended that at the root of Baker's problem lies his pursuit of contradictory goals. On the one hand, Baker wants to restore calm to the markets by showing that steps are being taken to narrow the U.S. deficits, especially the trade deficit that erodes confidence in the dollar. On the other hand, Baker wants to keep the U.S. economy expanding at as brisk a pace as possible, even though Americans' consumption must slow down to stem the flood of imports. Reconciling these two goals "is virtually impossible," Roach said.

Still, despite their skepticism, analysts described Baker's efforts as headed in a positive direction. For one thing, lower interest rates abroad should help the Federal Reserve keep U.S. interest rates from rising. This is because lower rates abroad prop up the dollar, thereby easing pressure on the Fed to defend the U.S. currency by tightening credit. (Higher interest rates in the United States tend to boost the dollar because dollar-denominated investments become more attractive.)

In the view of many economists, a major cause of the Oct. 19 stock-market plunge was a dispute between Baker and West German officials over Bonn's move to lift interest rates. The fact that West Germany's Bundesbank led yesterday's interest rate actions should help reassure the markets.

Similar arguments were advanced yesterday by U.S. officials. "The critical thing is that the international economic coordination process is working," said one American policy maker. A Group of Seven meeting between the finance ministers of the largest industrial countries, which is widely anticipated in the next few weeks, is hardly likely to produce all of the measures needed to correct global economic imbalances, this official said. "But this is all a major step in the right direction," he concluded.

Baker's hope -- shared by his counterparts in Britain, France and several other western nations -- is that the Bonn government, which controls the largest economy in Europe, will lead the way toward faster global growth by cutting interest rates and taxes. Speedier growth abroad, Baker contends, will increase demand for American products, thereby easing the U.S. trade gap. The Treasury secretary is aiming to get a commitment for such action at a Group of Seven meeting.

The events of the past few days suggest that Bonn is starting to respond to pressure. The drop in the dollar hurts German businessmen and farmers by making German products less competitive on world markets. The Bonn government is thus obliged to lower interest rates both to brake the dollar's descent and to minimize the risk that West Germany will suffer a recession.

According to U.S. officials, putting pressure on Bonn was the main motive behind Baker's willingness in recent weeks to see the dollar decline without taking measures to stop it.

But some analysts question whether this strategy will lead to anything more than cosmetic improvements in economic policy, given the U.S. failure to shrink its budget deficit substantially. The budget deficit contributes to the trade gap in a number of ways, including increasing Americans' appetite for goods.

"It doesn't look to me," said Paul Boltz, chief economist at T. Rowe Price Associates, "as if anything important is going to happen until after the elections.