What was going on when I was born?

The Koch administration has decided to seek a cut in taxes on commercial banks despite some internal opposition, and is expected to reach agreement with the state on specific legislation later this week. The opposition came from the city's Commissioner of Finance, Philip R. Michael, who said the move could cost the city millions in lost tax revenues. Mr. Michael, a mayoral appointee, made his objections known in a confidential memorandum to Mayor Koch. In that three-page memorandum, dated May 18, he argued that reducing the taxes on commercial banks would not only hurt the city financially, but would also fail to keep banks in New York, the main goal of those pushing for such a cut. Reducing the taxes would make New York more competitive with other parts of the nation, proponents of the idea maintain.

A tentative proposal to build a 25-story building on upper Fifth Avenue next to the turn-of-the century mansion that now houses the Jewish Museum is causing concern in the neighborhood and a renewal of efforts to have the mansion given landmark status. The Jewish Theological Seminary of America, which owns the museum and the land at the northeast corner of Fifth Avenue and 92d Street, says the museum needs more space for its exhibits and additional revenue for its upkeep. The proposed building, according to a spokesman for the seminary, is only one of the options under consideration. The seminary emphasizes that there are no plans to alter or destroy the former Felix M. Warburg mansion, which was built for the banker in 1907. It also asserts that one of the options being considered is just to leave the site as it is and find other ways to raise the necessary funds.

Despite the big movie and paperback deals that convey an impression of glamour and prosperity, the average author in the United States doesn't live on Easy Street. He or she earns less than $5,000 a year from writing, and has to make ends meet with the help of other jobs - or a working spouse. These are among the results reported in a major pioneering study to be issued today by Columbia University's Center for the Social Sciences about the economics, and frustrations, of professional authors in this country. ''On the average,'' the social scientists say, ''writing yields little economic return.'' Based on responses from 2,239 authors producing books in every field of fact and fiction, who were pledged anonymity, ''The Columbia University Survey of American Authors'' is a 150-page document that is the most detailed account ever made of how writers earn a living, or don't, and yet survive. For analytical purposes, an author was defined as a contemporary American writer who had had at least one book published. The Happy Minority While generally gloomy, the survey also notes that there is a great gulf -there are writers living on the poverty level and in the top 10 percent, making $45,000 or more a year, and the top five percent, with incomes of $80,000 or beyond.

Secretary of State Alexander M. Haig Jr. and Foreign Minister Huang Hua of China concluded the first of three days of Chinese-American talks today in apparent agreement on the need for closer strategic cooperation to counter Soviet activities around the world. A senior aide to Mr. Haig, in briefing reporters after the two-hour meeting, said there was ''a great deal of unanimity'' that the main problem in the world today was ''Soviet hegemonism.'' Hegemonism is the shorthand term used by the Chinese to criticize Soviet the expansion of Soviet power. Mr. Huang, in a banquet toast tonight, said that the Chinese ''attach importance to the strategic relationship between China and the United States'' despite the differences that exist between them ''in policy and viewpoint.''

Representative Ed Jenkins, a Democrat from a district of small farms and businesses in north Georgia, says he hopes the Ways and Means Committee ''can stick with across-theboard'' cuts in personal income tax rates. Representative Thomas J. Downey, a Democrat from a district of suburbs and small businesses on the south shore of Long Island, wants to find another way to cut taxes, perhaps by widening existing income brackets. Mr. Downey, Mr. Jenkins and three other Ways and Means Democrats will meet for the first time tomorrow as a task force appointed by the committee chairman, Dan Rostenkowski of Illinois, to advise the Democrats how best to shape this part of a tax-relief bill. Stresses Among Democrats The difference in approach between Mr. Jenkins, a conservative, and Mr. Downey, a liberal, is typical of the stresses that already have sundered House Democrats. Leaders of the conservative wing have pledged to support President Reagan's bill to cut personal tax rates by 25 percent over 33 months, starting with a 5 percent cut Oct.1. There would also be cuts of 10 percent on July 1, 1982, and July 1, 1983.

When Philip F. Johnson was sworn in as the third chairman of the Commodity Futures Trading Commission last Monday morning, no one had to introduce him to the staff or take him on a tour of the handsome Washington offices of the agency. Nor will anyone have to introduce him to the commodity industry, which has been unable to conceal its glee at his appointment. The 42-year-old Chicago lawyer has spent the last 15 years representing clients in the industry, most recently as general counsel to the Chicago Board of Trade, the nation's biggest futures exchange. He has also served on C.F.T.C. advisory panels from the agency's inception in 1974.

''You have come at a time when the international situation is tense and turbulent.

THE power-hitting third baseman had declared himself a free agent. His team demanded compensation. A strike was threatened and the future of the game seemed in doubt. After protracted negotiations, a bargain was forged: The team that had lost its slugger would henceforth get four outs an inning. The game resumed. Such a plan might not resolve the major league baseball strike, but it worked just fine in Van Cortlandt Park in the Bronx on Saturday afternoon. The bargaining was easier there because none of the players had reached his 12th birthday, a yellow tennis ball was substituting for regulation horsehide, and there were only 10 ballplayers and four mitts. This five-on-a-side, three-fouls-you'reout, team-at-bat-supplies-the-catcher game was only one of thousands that proceeded apace throughout New York City this weekend, oblivious to the major league strike. The third baseman's team pitied rather than resented him for jumping ship: he said his mother was taking him to the dentist.

Banks will not seem much different. They will be able to transact the new business from their old headquarters, using the same offices and the same personnel, at least for a while. But the new business represents an enormous opportunity. Banks in the United States, the Federal Reserve Board decided last week, may go after the corporate and government borrowing business now transacted in London, the Far East and island outposts in the Caribbean.

The heroes and the heroines were fed up. They had been doing their jobs under fire for six years, but this was just too much. The gunfire and hatred and insanity that had swept Lebanon from one end to the other now invaded one of the country's last sanctuaries, the American University Hospital of Beirut. For years the hospital, founded in the last century by Protestant missionaries, had treated the injured from all sides of Lebanon's internecine bloodletting with fine impartiality. Last week, for the first time, the hospital itself was the front line.

The Congressional budget process swept through its committee phase last week, producing one of the broadest packages of legislative changes in the nation's history as well as a victory for the Reagan Administration and the House and Senate Budget committees. Now, however, the Democratic-controlled House of Representatives must decide whether to accept the repeal or modification of scores of such programs as child nutrition, job training, student loans and aid to school districts near Federal installations. Administration officials and Republican Congressional leaders acknowledge that this will be a far more formidable task than the initial challenge of gaining Congressional approval of Mr. Reagan's proposed budget of $695.5 billion for the 1982 fiscal year. Panels Approve Specific Cuts Since the House and Senate adopted the overall budget ceiling last month, 31 committees in both houses have given preliminary approval to specific cuts of programs. They reduced projected spending by a total of more than $36 billion out of the $740 billion that the Federal Government would need in the next fiscal year if it continued current spending policy. That is the amount that would be spent beginning Oct. 1 if the Government went on ''automatic pilot'' and the President and Congress went home and let inflation and automatic refunding of programs take their course. The $695.5 billion level also reflects $9 billion in administrative savings that the White House says it plans to achieve by reducing fraud and waste.

Interior Secretary James G. Watt has abruptly ordered that the most controversial part of his plan to reorganize the Federal Office of Surface Mining go into effect tomorrow, at least on paper. In the interests of saving money and increasing state control over strip mine regulation, Mr. Watt had proposed ''an orderly phase-in'' of a sharply pruned Federal strip mining control staff in 16 new offices - 14 for liaison in the state capitals of coal-producing states and two centers for technical and engineering personnel in Pittsburgh and Casper, Wyo. The five existing regional offices were to be abolished over a yearlong period, beginning with the one in Denver. The plan aroused strong opposition from environmentalists, who called it a move to destroy the agency's watchdog power over reclamation of strip-mined land. Last Thursday, a Democrat-controlled House subcommittee approved a provision forbidding the Interior Department to use any money from the 1982 budget, which takes effect Oct. 1, to close or move the Denver office.