Generally speaking, television does poorly with anything relating to the economy. At the London economic summit in 1977, the chief correspondent for one of the major networks came to me with the final communique in hand and said:

"My God, what can we do with this?" Forget that Jimmy Carter and six other heads of state had agreed on several significant things relating to jobs, energy and inflation -- there were no visuals quickly at hand, just words.

This fear of grappling with economic issues is still pervasive. But tonight at 10 on Channel 9, CBS News bucks the trend with a documentary called "The Toyota Invasion," which spends an hour chronicling the amazing success of one major Japanese car company -- and, inferentially, explaining the sad state of affairs in Detroit.

I don't know whether this show, produced and written by Jay McMullen, will have what CBS considers a good rating. It has plenty of visuals to leaven the inevitable interviews with officials. It steers the viewer skillfully, with words and pictures, through an explanation of why the Japanese labor market and worker-company relationships differ from ours.

But I hope the officials who call the shots at CBS don't care what the ratings are, because this is a TV piece that shuns Detroit's simplistic excuses for its present economic mess -- or extended emphasis on the standard shot of unemployment lines there. This effort shows that TV can do some serious economic reporting when it wants to.

McMullen's script explains the Japanese success in terms of the American industry's greed and lack of vision. Detroit had its focus on the bigger car -- for bigger profits -- and left the small-car market wide open for anyone who would take it. And the Japanese, like good capitalists, did so.

With the camera panning to happy U.S. dealer-importers in Las Vegas examining the new merchandise for 1981, the narrator says: "What sells them is primarily their reputation for quality of production." And Toyota board chairman Masaya Hanai, bragging about his company's stress on modernization and productivity, slips a neat shiv into his American opposite numbers in Detroit.

"In this respect, it would seem that the management people in the U.S. are too busy with the pursuit of the short-term profits or with the need to satisfy shareholders eager for dividends. That is, they care less about yearly investments needed to make profits in the future," Hanai says through a translator.

Almost every independent study of the U.S.-Japanese business relationships -- most recently in the tragically ignored "Wise Men's Report" to the outgoing Carter administration -- has come up with a similar conclusion: American companies concentrate on the short-run perspective, the Japanese on the longer run. That's what pays off. Also, the United Auto Workers must share the blame for pushing wages up too fast, helping to price American cars out of the market. The CBS report tends to ignore this factor.

But my only real complaint is that after demonstrating that the Japanese success is the result of a cultural unity, a good product, some luck and stupidity in Detroit and Washington, "The Toyota Invasion" winds up in the last 10 seconds asking the wrong question:

"What are we going to do about it?" The right question is: Why should we do anything about it? The U.S. auto industry's problems have to be settled at home with a better and more competitive product.