Because of an editing error, a report on Bolivia in Friday's Post said scheduled elections next month would make Bolivia the first South American country since 1973 to trade military rule for democracy. In fact, the popular elections have already occurred and it is the transfer of power to civilian rule that is scheduled next month.

Plans to transfer power next month from Bolivia's military rulers to a democratically elected government are putting President Carter's human rights policy on the spot, according to policitians and diplomats here.

Bolivia, the poorest country in South America, expects substantial U.S. economic aid in return for holding free elections and scrapping 15 years of military rule.

However, U.S. diplomats here say that despite promoting human rights and democracy in Central and South America for the past two years, the United States is not in a position to offer Bolivia the amounts of new economic assistance or other rewards that Bolivians anticipate.

"There is still some flexibility (in U.S. aid programs), but not what we need," said one high ranking American diplomat here. "It's a part of our human rights policy where our mechanisms are not where our mouths are."

Yet without this aid, most Bolivian politicians - from Marcelo Quiroga Santa Cruz on the left to Waldo Cerruto on the right - believe that a democratic government will be unable to cope with the country's economic crisis, which threatens poltical stability here.

As it is, government in Bolivia tend to rise and fall with the seasons. There was a military coup last summer, and another one late last fall.

Now, however, many Bolivians appear to be fed up with military rule. Both Bolivian and foreign observers believe that if the new democratic government is overthrown, another military regime could run into armed opposition.

For these reasons and because many people here believe the Carter administration was instrumental in persuading the military here to hold elections, many Boliviann politicians will blame the United States if they are forced, once in office, to take severe austerity measures, which they believe would foment unrest. "It is in the interest of the United States to support Bolivia," Quiroga Santa Cruz said in an interview. "This is the first country to go through this process. It's very important because it will set a precedent."

The scheduled elections will make Bolivia the first South American country since 1973 to trade a military dictatorship for a democracy.

But Bolivia's economic plight and its history of revolving-door governments has aroused a measure of pessimism.

Middle class Bolivians, even those who are disgusted with the military and want a return to democracy, have begun to prepare for what they believe will be inevitable violence after the new elected government is installed Aug. 6.

They have begun to stock up on sugar, wheat, crackers, kerosene for cooking and bottled water because many of them see strikes, violence and possibly a civil war provides immediate aid of up to $100 million quickly, some Bolivians believe, the economy will deteriorate whithin weeks or months after the new government assumes power.

While some American diplomats here express concern, the official view of the embassy seems to be that, whatever the Bolivians may think and expect from the United States, there were never any promises made.

The Carter administration does want Bolivia to become a democracy on Aug. 6, these diplomats say, and Rosalynn Carter will probably lead an official delegattion to demonstrate this concern.

However, a massive and quick transfusion of unrestricted aid seems to be out of the question. Bolivia already received up to $60 million a year from the United States, one of the largest aid programs in the hemisphere.

If the new democratic government takes office as scheduled, the United States, according to American diplomats here, will probably respond with some additional assistance, and help refinance Bolivia's $2.5 billion foreign debt.

Interest on this debt, according to the Bolivian government and diplomatic observers, will account for almost $300 million of the country's expected $400 million balance of payments deficit this year.

To make matters worse for Bolivia's floundering economy and the United States' image here, the U.S. House of Representatives has passed a bill that would authorize the sale of $35,000 tons of tin from U.S. strategic stockpiles.The Senate is now considering the measure, which has the administration's backing.

It has been estimated that the sales could undercut the price of tin by $1 a pound, which would cost Bolivia $100 million dollars a year. Tin is Bolivia's main export.

"There will not be democracy in Bolivia with sales from the buffer stock," said Jose Luis Roca, a leading Christian Democrat politican and senator-elect.

Gen. David Padilla, Bolivia's outgoing military president, sent letter to President Carter this week asking the administration to stop the tin sales if they are approved by Congress.

Padilla said that the sales will have "the gravest effects on the Bolivian economy and could interfere, weaken and ultimately frustrate" the country's return to democracy. The White House has yet to respond to Padilla's letter.

Antonio Sanchez of Lozada, a former finance minister and Bolivian ambassador to the United States, has calculated that his country will need about $250 million in unrestricted foreign aid over the next three years to overcome its current balance of payments crisis and get its economic house in order.

Although he personally does not expect the United States to contribute significantly to an aid package of this dimension, he is convincing the money must come from somewhere if Bolivia is to avoid severe problems.