What was going on when I was born?

President Amin Gemayel has told Washington that Lebanon cannot afford the political costs of a treaty with Israel. News analysis, page A10. UNITED NATIONS, N.Y., Oct. 20 -The Arab countries have quietly abandoned an attempt to expel Israel from the General Assembly, Arab diplomats disclosed today. The diplomats said the decision was made Tuesday at a closed meeting of the 21 members of the Arab League. Instead of seeking to oust Israel this year, they said, the group agreed to express some form of symbolic collective reservation over Israel's credentials.

HIGH POINT, N.C. ''THIS is the first market in two years that has opened on an optimistic note,'' said Robert P. Gruenberg, general manager of the Southern Furniture Market, a wholesale center for more than 1,300 furniture manufacturers based here. ''Since about 60 percent of all furniture is bought on credit, the falling interest rates should have a positive effect on business,'' Mr. Gruenberg said. The optimism was cautious, for no one is sure when the economy will pick up. Furniture sales have been sluggish for several years now and retail-store buyers, who descend on this North Carolina town twice a year to shop furniture-showroom displays, don't seem ready to gamble.

The 1982 Nobel Memorial Prize for Economic Science was awarded today to George J. Stigler, a University of Chicago professor, for his half century of research on the working of industry and the role of government regulation in the economy. The citation by the Royal Swedish Academy of Sciences praised the 71-year-old economist's ''seminal studies of industrial structures, functioning of markets and the causes and effects of public regulation.'' The prize medal, to be presented in Stockholm on Dec. 10, carries with it a cash award of about $175,000. Economists said the prize further increased the prestige and influence of the ''Chicago School'' of economics, which favors monetarism, minimal regulation of industry and reduced government spending.

At the University of Chicago's business school, a popular item of attire is a T-shirt showing a back view of an odd couple of economists strolling together down a leafy walk. The very short one is Milton Friedman, the monetarist who is considered the core of the conservative Chicago school of economics; the very tall one is George J. Stigler, a professor at the business school and a longtime champion of deregulation. Mr. Friedman, 70 years old, won the Nobel Memorial Prize in Economic Science in 1976. Yesterday his friend Mr. Stigler was also awarded that prize. In a telephone interview, the tweedy, whitehaired professor was asked where the two economists parted company. ''Milton's out to save the world,'' he said, ''and I'm out to understand it.''

The stock market's most popular indicator - the Dow Jones industrial average - raced ahead 20.32 points yesterday to finish at 1,034.12, its highest level in nearly a decade. Analysts credited some surprisingly good earnings reports with providing part of the stimulus for the advance. Blue chips led the way, but an impressive majority of issues also shared in a session that saw the Dow extend its phenomenal gain to 257.20 points within 10 weeks. The rally began on Aug. 13, with the industrial average mired at 776.92. At that juncture, declining interest rates and signs of an easier monetary policy by the Federal Reserve Board touched off the advance.

International The Arab countries have abandoned an attempt to expel Israel from the United Nations General Assembly, Arab diplomats disclosed. In an alternative policy, the 21 members of the Arab League agreed to express a symbolic reservation over Israel's credentials. On Saturday, the United States said that, if Israel was expelled, it would leave the General Assembly and suspend its United Nations payments. (Page A1, Column 6.) France is willing to send more troops to reinforce the peacekeeping force in Beirut, according to an offer made by President Francois Mitterrand to President Amin Gemayel, a French spokesman reported. He said no figures were mentioned. (A8:1-2.)

The burglars who broke into Theodore Roosevelt's birthplace last year were probably young, very ordinary thieves who entered the brownstone on Manhattan's East Side looking for objects they could steal easily and sell quickly, authorities say. The burglars came to the home three times, and Federal officials say that each time they made off with pieces of Roosevelt's past - from a small bronze statue he had loved as a child to guns he had carried as a young man. Now, the officials who manage the birthplace - a national historic site at 28 East 20th Street - say they are not only upgrading the security system in the home, but they also have removed some historic items from public display and have requested that an armed guard be assigned to the site. ''It's a very sad commentary, but these historic sites are not immune to the crimes that plague the city itself,'' said Duane R. Pearson, superintendent of the five national historic sites in Manhattan operated by the National Park Service.

A United Nations study sharply critical of the International Monetary Fund's loans to South Africa has languished unpublished for more than a year, according to U.N. officials. The study charges that loans from the monetary fund have helped South Africa maintain its system of apartheid and have contributed to that country's military buildup. In addition it concludes that the I.M.F. has treated South Africa more favorably than other African countries and has ignored declarations by the General Assembly and Security Council that South Africa's occupation of Namibia is illegal. Jean Gazarian, director of General Assembly Affairs in the office of the Secretariat, said he could recall no other instances in which a United Nations report of this nature was not published as an official document and translated into the U.N.'s official languages. He called the treatment of this report ''very strange'' but said he did not know what had happened.

Ten thousand people, many carrying banners declaring ''Solidarity Lives,'' crowded into a small cemetery here today for the burial of a demonstrator who was fatally shot by the police last week during clashes sparked by the outlawing of the Solidarity trade union. The funeral of the demonstrator, Bogdan Wlosik, a 20-year-old electrician, had the overtones of a rally for the banned union as the mourners lining the coffin's path and crowding around the grave raised their hands in the V-sign that has became a symbol of resistance to the martial-law authorities. Police Patrols in City Center Less than a mile away, patrols of riot policemen saturated the center of Nowa Huta, a steel town built on the edge of the ancient city of Cracow during the 1950's as an example of the new, socialist way. A statue of Lenin, which workers tried to destroy during street fighting last week, is now protected by a corrugated steel fence.

Because of a technical error, the obituary of John Michelosen yesterday omitted part of the first sentence. It should have said that Mr. Michelosen became head coach of the Pittsburgh Steelers and later of the football team at the University of Pittsburgh.

President Reagan, campaigning in this economically distressed farm and industrial area, announced today that in the next three years the Agriculture Department would make available $1.5 billion in credits to spur farm exports and that the Farmers Home Administration would reduce loan rates effective Nov. 1. Mr. Reagan also said that he would ''enthusiastically consider'' any proposals to lift the American ban on parts for the Soviet Union's 3,700-mile natural gas pipeline from Siberia to Western Europe and replace it with economic sanctions less harmful to European and American manufacturers. 'Constant Consultations' It was Mr. Reagan's strongest comment yet about the possibility of lifting the pipeline ban. Mr. Reagan said his Administration had been in ''constant consultations'' with European allies about ''alternative measures that would be equally or more effective'' against the Russians. ''Certainly if we can establish restrictions that put greater pressure on the Soviets and less on our own companies, we will enthusiastically consider them,'' Mr. Reagan told 6,000 cheering supporters of Representative Robert H. Michel, the House minority leader, at a re-election rally this evening.

The New York Stock Exchange yesterday fined a prominent brokerage firm $400,000 for permitting the Hunt brothers of Texas to speculate so heavily in silver as to endanger the firm's survival and then failing to give the stock exchange timely notice of the developing crisis. The fine, against Bache Halsey Stuart Shields Inc., was the largest ever levied by the exchange. In a related development, a 279-page staff report of the Securities and Exchange Commission, released in Washington, assailed the stock exchange for insufficient surveillance of Bache and other brokerage firms dealing with the Hunts in the weeks leading up to the silver crisis in the spring of 1980. Failure to Get Information In some of the strongest language to come from the regulatory body under the chairmanship of John S.R. Shad, a former executive of the E.F. Hutton brokerage firm, the S.E.C. staff said that the exchange had failed to get sufficient information from Wall Street firms dealing with the Hunts, had failed to verify the little information it got and had ''failed to be alert to the potential of a crisis situation as it developed.''