Amid the endless efforts to analyze the ailing U.S. economy, two motifs mournfully recur: the American entrepreneurial spirit is dying; the American worker's productivity is plummeting. I think I know why. America has turned into Show Business, U.S.A. Oh, I don't mean that actor-in-the-White House stuff. I don't think Ronald Reagan is our first actor president. He's just the first one with screen credits. What I have in mind is far more pervasive. As Jimmy Durante used to say, "Everybody wants to get into duh act!"

I recently took a trip that made it all clear to me. The first leg was to New York or, as the airline carrying me described it, "The Big Apple," an old show biz term. The flight attendants wore not uniforms but costumes, the kind you'd associate with a 1940s MGM musical. The young lady giving the safety instructions told jokes. While we waited on the runway, she told more jokes. Airborne, she and another attendant sang and danced in the aisle, serenading someone with a chorus of "Hey, Big Spender." (Honest!)

My New York taxi driver asked me if I was Polish, but I've learned to forestall that stuff by looking really stern and saying that I am. He then told me jokes about how many Croatians it takes, etc., all the way to Manhattan.

You expect television to be show biz, but my hotel-room viewing reminded me that Phil Donahue regularly invites wife abusers, drug addicts, rape victims and other entertaining groups to bare their most intimate personal experiences for the delight of studio and at- home audiences. If that's not tacky enough for you, David Susskind and Tom Snyder can usually lower the level a little. Snyder recently gave us an evening of enchantment with Charles Manson, prompting speculation that Manson might be eyeing the California governorship.

In New York, I tried to interview a political media consultant about the future of the Democratic Party. He only wanted to tell Jerry Brown jokes. (Forgive the redundancy.) Another heavyweight political manipulator wanted to know how I liked him on radio. There were also some Tip O'Neill jokes.

A few days later I was actually in the video-vacuous state, having arrived in San Francisco. This is where it started to get grotesque. I was en route to an interview with a confessed murderer (no, I am not writing a new sit-com), who is incarcerated in San Quentin. Driving out there, my colleague and I pulled into a gas sation to ask directions. Watch, I said facetiously, he'll do a San Quentin joke. Playing the straight man, my friend asked how to get to San Quentin. "Rob a bank!" came the instant reply. Finally extracting directions, we got to the prison, and began the complex process of visiting an inmate. At one point, we were to follow a series of yellow dots along a corridor. I had a premonition. The guard's going to do a "Wizard of Oz" joke, I predicted. Sure enough, we were told to "follow the yellow brick road." When we didn't crack up, our Department of Corrections munchkin looked very disgruntled indeed.

Our inmate, a man who has committed two violent crimes, proved affable, in his sunglasses, jeans and yellow pullover. He told anecdotes and discussed the Manson and Sirhan interviews on TV. He told us a joke too obscene for this forum and several Jerry Brown jokes that are too familiar. He writes articles in his cell, and insisted on giving us a Polaroid shot of the three of us in the prison yard.

Murderers can now give interviews and tell jokes and score in the ratings, and public officials fill the nightly news with one-liners. Jane Fonda, Ed Asner, Robert Redford and John Denver regularly offer their views on major social issues and regularly get more exposure than Gunnar Myrdal or Margaret Mead ever dreamed of. Jack Klugman can testify before Congress on medical matters. (Haven't you seen "Quincy"? I still think of him as Oscar on "The Odd Couple.")

Small wonder we are turning into a nation of stand-up comics and rock musicians. Why start a new business or try to improve a product or service when you can have fun like they do on the boob tube? We have evolved from a hard-working nation that looked up to Andrew Carnegie and Henry Ford to a pop culture that admires Reggie Jackson, the actor/ballplayer, and Ro bert Redford, the actor/environmentalist. What's happened to the work ethic? Ask yourself this: when have you even seen anybody work on television?