Next year in the Philippines probably will be a grim one of rising inflation, a declining economy and political instability.

After three years of economic growth rates of more than 5 percent, many economists predict recession in 1991, with sharp increases in unemployment, especially if war breaks out in the Persian Gulf.Higher oil costs that followed Iraq's seizure of Kuwait on Aug. 2 forced the government to raise consumer fuel prices more than 45 percent.

That sent shock waves through an economy already struggling with double-digit inflation, and there are clear signs the business community is losing confidence in President Corazon Aquino.

The Philippines gets 64 percent of its energy from imported oil, and more than 80 percent of it comes from the Middle East.

New foreign investments declined 47 percent in the first eight months of 1990, and the departure of capital rose 342 percent as financiers moved their money to more stable havens.

"We have not only lost our sense of bearings, we have taken leave of our senses," Teodoro Benigno, Aquino's former spokesman, wrote in the Philippine Star. "The Philippines is now looked upon abroad as a basket case."

Annual inflation of about 12 percent, is expected to reach 16 percent even without war in the gulf. That will lead to demands by labor for wage increases industry says it cannot afford.

"Strikes and demonstrations are going to abound in the months ahead," Political and Economic Risk Consultancy Ltd. of Hong Kong said in a report last month. "The government is widely perceived as being helpless."

Aurelio Periquet, president of the Philippine Chamber of Commerce and Industry, said industrial output could decline 40 percent in 1991 because of higher fuel costs and a chronic energy shortage.

Labor Secretary Ruben Torres said recently that unemployment in this nation of 60 million people may rise to 13 percent from the current level of 9 percent.

A national election scheduled for 1992, with no clear successor to Aquino in sight, virtually guarantees political uncertainty. The president has said she will not seek a second term.