What was going on when I was born?

The recent decision by New York State's Public Service Commission to give the Consolidated Edison Company the full 15 1/2 percent rate increase it had requested was shaped in large part by a growing mood among regulators that they must help bolster flagging investor confidence in the public utility industry. ''For the public regulators, it's a whole new ball game,'' said Commissioner Anne F. Mead, who has served on the commission since 1975. ''Given the state of the economy and the competition for capital in today's markets, we have to send some signals to the investment community.'' Consumer advocates and critics of the rate increase - the largest on record in New York State - argued that the decision was proof that the rate-making process was biased in favor of utilities. The five P.S.C. commissioners, who voted unanimously to approve the rate increase, disagree. In separate interviews, they argued that evidence in the case, which took up more than 10,000 pages in legal briefs, exhibits and hearing testimony, left them no choice but to give Con Edison the full $449.5 million in new revenue it requested.

With companies now reporting their first-quarter earnings, the early returns generally show a considerable, even surprising, measure of strength in corporate profitability, according to economists, Wall Street analysts and professional investors. There are key industries, the analysts recognize, that for various reasons will report sharp year-to-year declines in earnings. Chief among them are automobiles, oil, semiconductors and nonferrous metals. Given the sluggish economy and high interest rates, however, the nation's corporations seem to be performing quite well.

It is 9:05 A.M. and Thomas B. O'Donnell, a 28-year-old professional money shopper, is about to make his first purchase of the day. Advised that interest rates will dip as the morning ticks away, Mr. O'Donnell seeks a bargain. The First National Bank of Chicago's London branch is known to have 60-day Eurodollar certificates. They are paying 15.70 percent in interest, Mr. O'Donnell is told via telephone by a First Chicago salesman. ''I understand the market is at 15.80,'' Mr. O'Donnell replies, courteous and alert as he raises the flag of the Union Cash Management Fund for another day of genteel jousting in the international money markets. ''Would you be willing to match it?''

''In Poland they will be celebrating Easter as they have not since 1939. It is a new spring in their lives that they weren't able to celebrate before.'' -The Rev. Stanley J. Adamczyk, pastor of the Church of the Most Sacred Heart of Jesus in Wallington, N.J. (B1:1.)

Pitching his first game since last August, Craig Swan was beset by a fielding error, a quirky play and misguided Met base running yesterday and lost to the Montreal Expos, 4-3, in the first game of a doubleheader. In the second game, a hard-hitting affair that extended into the twilight, Dave Kingman hit a three-run home run, his first since returning to New York this spring, and the Mets won, 7-2. They put the game out of reach with a five-run third inning in which Rusty Staub doubled to drive in Frank Taveras, Kingman drove the ball over the left-field fence, and Doug Flynn, who has hit in all eight games this year, drove in Hubie Brooks with a double. Pat Zachry, unbeaten in three starts, pitched a complete game, allowing four hits.

The Soviet diplomat in the Seychelles was trying to show candor as he spoke with a visitor in the garden of his embassy in the island group in the Indian Ocean. ''You cannot really believe that we would disrupt Western oil flows,'' he said. ''That is not in our interest.'' The United States military attache in India struck an equally confidential tone. ''In this world, with missiles, you can't worry too much about the other fellow's intentions,'' he said. ''You have to concentrate on his capabilities, and right now, today, the Soviets have the capability to mine the Straits of Hormuz and move troops and tanks from Afghanistan to Iran.'' For more than a decade military analysts have written papers on the vulnerability of oil routes from the Persian Gulf, and military historians have speculated about who would fill the power vacuum left in the Indian Ocean after the withdrawal of the British in the 1960's. Now there is an urgency to the discussion.

The boys in Detroit are not going to believe this. Marvin Runyon, an old Detroiter, one of those real auto men who started on the assembly line, was sitting in his office, a converted Air Force barracks, and pondering management techniques: Should the workers at the new plant do calisthenics for 15 minutes before work? Should the new plant give workers their pay only partly in wages and the rest in bonuses if quality and productivity meet expectations? And the company's insistence on no inspections, the notion that good workers perform to expectations, that inspections are unnecessary, will this work in America? A 37-year veteran of the Ford Motor Company, Mr. Runyon, now 56 years old, retired in June 1980 after a distinguished career that saw him direct two plants, help build eight plants and end as a vice president. Now, he is president of the Nissan Motor Manufacturing Corporation U.S.A., and here in Smyrna, an essentially rural town of 8,600 people, 18 miles southeast of Nashville, Mr. Runyon is directing an invasion, construction of a $500 million truck plant where the Nissan Motor Company, the parent organization, will produce as many as 180,000 Datsun light trucks a year. Moreover, Nissan intends to import at least some of its highly acclaimed Japanese manufacturing methods as well. It appears that the plant will be an experiment in foreign investment and foreign methods.

The Household Finance Corporation, spurred by rising interest rates and the potential collapse of the consumer loan business, undertook an ambitious diversification in recent years that put it in the leasing business, for ships, trailer trucks and computers, and in manufacturing, of barbecue grills and water coolers. Since the diversification plan began, however, the company's earnings growth has slowed dramatically. Some analysts question the strategy. With its two most recent acquisitions, Household Finance has strayed even further from its traditional business of making personal loans for consumer goods, debt consolidation and emergencies. The $300 million purchase in February of the Wallace Murray Corporation, a manufacturer of engine parts, pipe fixtures and specialty tools, and the $30 million acquisition last December of an airline, Wein Air Alaska, have put Household Finance into industries that have had more than their share of trouble lately.

An article in Business Day Friday about Manufacturers Hanover Corpor- tion incorrectly compared the differ- ence in first-quarter net operating earnings this year and last and incor- rectly reported the rank of the bank. After-tax net operating earnings of Manufacturers Hanover, the nation's fourth largest banking organization, were $3.4 million higher in this year's first quarter than in the comparable 1980 period.

Which of the following statements is true: the Reagan Administration's tax relief proposal is fair because it would give larger percentage cuts in taxes paid to lower-income wage earners than to upper-bracket taxpayers; the proposal is unfair because it would result in larger percentage rises in after-tax income for upper-income taxpayers. In fact, both statements may be regarded as true. As the table on the effects of the proposal shows, in the Administration proposal the percentage reduction in taxes paid goes down as income rises. Conversely, the percentage rise in after-tax income goes up as income rises.

Two men who were members of the Black Liberation Army are being sought as ''prime suspects'' in the wounding of two New York City officers, one critically, last Thursday, the Police Department said this morning. The two men, whose names were not released, became the leading suspects when the police found their fingerprints in a van used by the officers' assailants, according to Alice McGillion, deputy police commissioner for public information. The search for the two suspects in the shooting of the officers is nationwide but has been most intense in Newark because of the identification of the two suspects and the fact that both the van and another vehicle used by the two gunmen involved in the shooting had New Jersey license plates.

The Ministry of International Trade and Industry has prepared a compromise plan to limit Japanese auto exports to the United States to 1.7 million units in 1981, about 120,000 fewer cars than last year, according to MITI officials quoted by the Kyodo News Service. Separately, Rokusuke Tanaka, the Minister of Trade and Industry, in charge of negotiations with the United States on the auto issue, told the Japan Broadcasting Corporation that a plan being discussed in the United States to limit Japanese shipments to a maximum of 1.6 million cars for a three-year period had a quota that was too low to negotiate ''On the basis of such figures we cannot get down to talks with the Americans,'' he said. Seeking Agreement Japanese and American officials have been trying to reach agreement on reduced Japanese auto exports in advance of a visit to the United States by Prime Minister Zenko Suzuki for talks with President Reagan in Washington May 7-8.