What was going on when I was born?

THE county's economy could experience some slow, steady growth this year, but the same forces that have given it strength during the recession could eventually lead to its deterioration. Those are some of the conclusions recently agreed upon by analysts and officials who monitor the county's economic well-being. The word they used most often in describing the county's economy was ''stable,'' saying that a service-oriented work force has insulated it against severe economic downswings and stimulated retail growth. However, they said, that same work force could ultimately overtax key components of the county's support system such as housing and transportation, producing economic declines. ''We really don't expect any deterioration in Westchester's economy during 1984 after the good experience it had in 1983,'' said Soyna Kornreich, the State Department of Labor's principal economist for the New York City area. She noted that unemployment in the county has continually been significantly lower than the state and national averages.

Disposable Funds The growth of consumer spending - always an important economic statistic because it accounts for roughly two-thirds of the nation's gross national product - appears likely to hold steady, economists are saying. This is expected to be confirmed when the Government announces December's personal income figures Thursday, in effect saying how much consumers can spend. But whether consumers want to spend often depends on their ''household net worth'' - not including the value of their homes. Since the stock market upturn that began in August 1982, household net worth has soared by more than $1 trillion - much of that traceable to increased stock performance. As for personal income, Rosanne M. Cahn, an economist at Goldman, Sachs & Company, expects the December figures to show a slight year- to-year rise of eight-tenths of 1 percent, compared with seven-tenths of 1 percent in November and 1.1 percent last October. What consumers spend or save is actually disposable income - personal income minus taxes. Gobbling Up Food Stocks Because people have to eat whether stock prices move up or down, food company shares are usually favored by investors as ''defensive issues'' when the market retreats. At such times, the highly visible earnings and dividends of food companies reassure investors. But when the market is strong, investors are more willing to settle for promises than performance.

PARIS Two metro stops past the Paris city line, in an old abandoned warehouse in the working-class district of Issy-les-Moulineaux, the French director Claude Chabrol is setting a scene as complex as a Bruegel tableau. It's pre-World War II France - a union meeting hall. Battered and bloody workers return from the streets outside, where their rally has been broken up by Fascist thugs. A hundred separate dramas are going on at once: injured bodies strewn here and there; a doctor rushing from one to the next; the heroine searching for her boyfriend and coming upon her future lover; telephones ringing at odd moments; marchers dashing in and out. It is an intricate shot, made more complicated by Mr. Chabrol's decision to film it continuously, in one unbroken four-minute take. But Mr. Chabrol, wearing a mischievous smile, is obviously in his element. A smallish man with rounded shoulders and an ill-fitting suit, he delights in small flashes of humor and small, human, cinematic touches. ''There are lots of films now about robots, made with robots,'' he says, carefully filling his pipe. ''I'm afraid they might be for an audience of robots, too. Me, I'm interested in people.''

President Hafez al-Assad of Syria said today that he would not withdraw Syrian troops from Lebanon until United States marines and other foreign troops had left, the Syrian press agency said. Mr. Assad made the comments after talks with Donald Rumsfeld, the United States special envoy to the Middle East. Previously, the Syrian President had opposed calls for the simultaneous withdrawal of Syrian and Israeli forces from Lebanon. His comments today, reported by the Syrian press agency, represented a stiffening of Mr. Assad's demands for pulling Syrian forces out of Lebanon.

John McEnroe avenged three humiliating 1983 losses to Mats Wilander by dominating the teen-ager, 6-2, 6-4, yesterday to move into the final of the Volvo Masters tennis tournament. There he will meet the man who beat him here last year in straight sets, Ivan Lendl, who powered his way into the final by beating Jimmy Connors yesterday, 6-3, 6-4. Even though the Masters title, which Lendl won the last two years, is still to be contested, both men agreed that the current No. 1 ranking was no longer at stake. McEnroe entered this event ranked first on the Association of Tennis Professionals computer, with Wilander - who was seeded first in this tournament - his primary challenger on the strength of his nine Grand Prix titles. While Lendl was the leading money winner in 1983, with $1.6 million, he failed once again to win a major title. The Masters determines the champion of the 1983 Grand Prix circuit and sometimes cements the rankings for the year just finished.

In his famous 1945 essay ''Who Cares Who Killed Roger Ackroyd?,'' Edmund Wilson dismissed detective stories as ''wasteful of time and degrading to the intellect.'' ''With so many fine books to be read, so much to be studied and known,'' he argued, ''there is no need to bore ourselves with this rubbish. And with the (wartime) paper shortage pressing on all publications and many writers forced out of print, we shall do well to discourage the squandering of this paper that might be put to better use.'' For Wilson, as for many critics, the reading of mysteries was ''a kind of vice that, for silliness and minor harmfulness, ranks somewhere between smoking and crossword puzzles,'' and certainly in its Michiko Kakutani is a book critic for The New York Times. purest incarnation the classic detective story remains an inherently conservative and moralistic form. American critics, however, have always been slower than their European colleagues to recognize the possibilities of the genre - Camus, Malraux, Gide, Chesterton and Maugham, for instance, all issued passionate defenses of it. And, as a body of critical work has begun to accumulate in this country, it becomes clear that the mystery in many ways represents a basic narrative model (it can be argued that such works as ''Bleak House,'' ''P ere Goriot'' and ''Crime and Punishment'' are mysteries) and that writers of suspense stories and ''serious'' fiction have actually carried on a dialogue for years.

Where does reality programming go now, and, along with that, a corollary question: What is reality, anyway? Television took a giant step in an uncertain direction last week with ''Something About Amelia,'' a drama about incest. The drama was, as ABC and its publicists had said it would be, tasteful and discreet, with nothing explicit, nothing offensive, and thoughtfulness all around. Moreover, at the close of ''Something About Amelia'' a solemn message appeared on screen. ''This story dramatized a therapeutic approach to the problem,'' it said, and reminded viewers of the high- mindedness of what they had seen. After all, there is nothing exploitative about a ''therapeutic approach.'' Indeed, it suggests that ABC was performing a public service.

Reagan Faces The East and Smiles Politely The Administration played the big power game last week, saluting China's Prime Minister in Washington and putting the best face it could on the freeze in Soviet-American relations. Prime Minister Zhao Ziyang received a warm welcome from President Reagan on the first leg of an election-year exchange, to be rounded off with a Presidential visit to Peking in April. And Secretary of State George P. Shultz said before leaving for Europe yesterday that he would meet Soviet Foreign Minister Andrei A. Gromyko this week ''in a constructive spirit.''

When the play ''Edmund Kean'' with Ben Kingsley ran in London last year, the production cost $30,000 and the top ticket price was $13. When the identical play and actor came to Broadway earlier this season, the production cost $150,000 and the best seat was $32.50. The higher price of producing - and seeing - ''Kean'' in New York is not an isolated example of the higher cost of theater on Broadway compared to London. Virtually every play that moves to Broadway from the commercial theaters of London's West End is more expensive here, in many cases as much as five times more costly. Most producers and theater owners in New York object to the making of an economic comparison with London, arguing that the higher price of theater here is consistent with the higher level of a variety of goods or salaries. Nevertheless, the disparity in theatrical costs considerably exceeds the average difference in wages and the cost-of-living between England and the United States. Nor does the growing strength of the U.S. dollar in relation the British pound - a gain of about 33 per cent by the dollar since 1978 - account for the gap in theatrical finances.

TO FOSTER ''greater competitive equity'' in New Jersey's health-care system, the Statewide Health Coordinating Council has called for government regulation to be extended to more health-care providers. This influential panel has concluded that some doctors and medical corporations should be subject to planning requirements that now affect only hospitals and other health- care facilities. In a controversial report to be presented this week to Dr. J. Richard Goldstein, the state's Commissioner of Health, the council recommends that doctors be required to get state approval if they want to build offices worth more than $1.5 million or buy medical equipment costing $400,000 or more. Such approval is known as a Certificate of Need.

Brooks Atkinson, the nation's most influential critic at a time when American drama first emerged as a serious art form, died of pneumonia yesterday at Crestwood Hospital in Huntsville, Ala. He was 89 years old. Mr. Atkinson had the opening-night seat as drama critic of The Times from 1925 to 1960. He took a four-year break in the 1940's and won a Pulitzer Prize in 1947 for foreign correspondence. He had been seriously ill since November and entered the hospital on Dec. 7. He had moved to Huntsville in 1981 from his farm in Durham, N.Y., to be near his family.

GEORGE LINDNER lives in North Salem, a land of spacious old homes on four-acre lots, a land where Mercedes- Benzes share the road with mounted fox hunters - but a land with no cable television. ''I read a lot,'' Mr. Lindner said. He sits on the town's cable television committee, which has been trying for more than a year to find a company willing to wire the town. Lewisboro and Pound Ridge are without cable, too, and several other towns in northern Westchester are only partially wired. In the more densely populated south, all of the municipalities are wired.