"Things were better when they were worse," Marcello Mastroianni used to say, once film stardom clutched him in joyless embrace.

In "The Good Years," Caroline Bird projects this notion in a future tense. The wild, prosperous good times of post-World War II will not roll this way again. But life will be better all the same. The American dream of full employment, an expanding economy and room at the top "was a valid promise during the centuries it took to exploit a continent of untapped resources," Bird writes, "but it could not last forever . . . We have had reprieves--usually by wars--but now that war is unthinkable the slowdown is upon us."

But the slowdown--the "steady state" economy--will bring new values in its wake. A sort of dolce vita will set in, and less will seem like more. Workaholics and overachievers lose their relevance in this scaled-down scene; it's the cheerful and patient folk who wait in line for the bus (run by a user-friendly computer) who rule the day.

As for the work ethic, you'd better like your dead-end job, because it could be the only one you'll ever get. Forget about promotions (no room at the top, remember). For incentives, employers will have to make dull jobs more interesting and spruce up the working conditions, Bird thinks. The inventive will discover new services that are needed and branch out on their own. People will take more interest in outside projects than in their work, and with more time to look around, they'll start to enjoy life more.

Two sets of people are already into the slowed-down mode: the young people who have opted out of the rat race and moved to the country to raise goats, and the old people, "the quiet few." Some of the "quiet few," anyway. "If you look around at people you know who are over 60," Bird writes, "you see that they are divided into two nations: the old, who are in need of welfare services, and people who aren't called old because they are doing all right." She calls these the "ageless."

Since the number of people over 65 is going to double by the year 2030, and the people who are already over 60 are going to live longer, she thinks it behooves us to study how the "ageless" get that way, if we want to be in shape for nirvana when it gets here. On a Ford Foundation grant, Bird roamed the country, probing for clues.

A good education and mental curiosity were recurring themes. Once limited to the privileged few, that kind of stimulus can be had by all. It also helps to be rich. Armand Hammer, 82-year-old chairman of Occidental Petroleum, didn't have to queue up at American Express before he bid on Leonardo da Vinci's diaries at a London auction; cash flow is no problem when William S. Paley steps out at night with a pretty young woman on his arm.

Some of the ageless are indestructible. At 78, Mary Calderone, the sex educator, proclaims: "I bake my own bread and slather it with margarine. I sleep soundly eight hours a night. And I never have jet lag. I just get off a plane anywhere in the world and eat whatever meal is next being eaten there." The ageless haven't followed a pattern, Bird concludes. "They have simply responded imaginatively to the accidental situations they have encountered."

A terminal optimist, she is convinced that new perceptions in the next century will pry open the doors to a better life. Not the least of the changes will be a new flowering of "recreational sex" among the elderly. There's more of it going on right now than people own up to, Bird assures us, and with the medical/technical advances in replacing worn-out parts, the sky could be the limit. The women will outnumber the men, to be sure, even as they do now--only more so. But one man could share unwedded bliss with several women, old and young, Bird suggests, so no one need feel left out. All that is left is how we pay for all this, and it is here that Bird's blueprint grows fuzzy at the fringe. Nothing short of a cataclysmic depression would blast us out of the economic mind-set we're imprisoned in. But the pain would be worth it, she insists.

Once the rubble is cleared away, "the problems created by the dilemma would disappear, and all sorts of wonderful dreams would become not only possible but so logical that they would be likely." The dreams, some "frankly designed to shock," include repudiating the national debt, finding better things to compete for than money, paying for transportation by taxes, and giving the tickets away free . . . And it was here that she lost me, sports fans. What dazzle would be left in life, what challenge, what mystery, heartbeat and rapture, if they take away the Farecard machines?