In the 1960s, the sheer numbers of adolescent baby boomers translated into teen power, particularly in the marketplace; during those years, if a 15-year-old sneezed, the nation caught a cold. Then the proportion of teens in the population fell, and so did public interest in their problems.

But a new teen wave is coming. We may have just enough time to avert disaster -- or, if we take an optimistic point of view, to maximize the benefits.

Nowhere is this more evident than in the two bellwether states, Florida and California. "These two states are at the forefront of the nation's demographic changes. Both are highly diverse, ethnically and racially, and we share similar age trends," says Amy Abraham, director of policy for Children Now, one of California's leading children's advocacy organizations. "The way we cope with the coming changes will set the tone for the rest of the nation."

The basic question we'll have to answer is: Are teenagers assets or enemies?

"Even more now than in the past, (the) public and policymakers tend to view teens as a threatening species," says Jack Levine, director of the Florida Center for Children and Youth, and one of the nation's most articulate child advocates. "We don't know much about them; we aren't comfortable with them; we certainly don't want to embrace them; and we feel we need to contain them. Kind of like . . . snakes."

One reason for this attitude: adult amnesia. "It's pretty hard to 'fess up to the fact that, when we were teens, we weren't so attractive, appealing, or socialized," says Levine. Or maybe some of us remember all too well just how unappealing we were, and we'd like to forget it. Soon, we won't be able to forget.

During the next 15 years, the proportion of the population made up of teenagers will increase by 23 percent, according to James Fox, a dean at Boston's Northeastern University. In Florida and California, the increase will be greater.

"In Florida's case, it's going to be a tidal wave," says Levine. "During the past decade, Florida experienced about a 10 percent increase in the number of teens, but over the next dozen years, the increase will be six times that rate."

Although good studies are hard to come by, California is probably comparable to Florida. A new report from the Department of Finance says that, by the year 2010, the number of Californians between the ages of 15 and 19 will grow by 60 percent, compared to the overall population, which will increase by 41 percent.

Because states use different methods to forecast, it's difficult to make direct comparisons between states. And no projection can account for unseen economic or social cataclysms -- or unpredicted improvements in the social fabric. While much of the news we hear (or write) about adolescents is negative, the volunteerism, technological prowess, and even optimism found among many teenagers is impressive. For two states in need of youthful creativity and energy, the teen wave could be a boon.

The U.S. Department of Justice recently announced that violent teen crime had dropped slightly for the second year in a row, good news to those worried about the teen wave.

Nonetheless, the potential negative outcomes -- and the need for preventive action -- should not be ignored, according to Levine. "In Florida, almost every indicator, from safety to education to safe-sex practices, suggests that teenagers will threaten us more than reward us. That's not an easy thing for someone who's been a child advocate for 16 years to say."

Overall, crime in major cities among adults has decreased in recent years. Among other factors, that decrease may have something to do with the aging of the boomers -- and may disguise the burgeoning crime rate among teens. During most of the past decade, arrests of Florida teenagers grew by 93 percent. "If, in the next decade, the number of teens grows as much as we believe it will, the teen arrest rate could increase by 500 percent," says Levine.

California's Abraham echoes his concern. "In our state, the number of teens murdered more than doubled during the past 10 years," she reports. "A large percentage of these teens were killed by their peers." Also, since 1991, California has incarcerated juveniles at a higher rate than has any other state, a rate twice the national average.

Meanwhile, California has the highest youth unemployment rate in the country.

Despite the grim projections, a sense of emergency exists in neither state. California voters and policymakers show little interest in expanding or saving current social and education programs. Nor is Florida preparing for the teen wave.

"In the next dozen years, the University of Florida system will likely face a six-to-one increase in applicants," says Levine. "But just last year, the system turned down five of every six applicants." Rather than investing in success, in education, Floridians and Californians "are paying for the monuments of failure. Public investment is going to prisons, and so will the kids."

"The situation isn't hopeless," Abraham cautions. "Not if we quickly expand the successful programs and strategies that we know work with kids at risk." She says government alone can't solve the problem -- individual families and civil-society institutions must also confront the rise of fatherlessness and teen pregnancy. But a positive outcome is unlikely if public agencies remain disengaged.

As Levine says, "Among the government programs that serve teens or children, just about the only one without a waiting list is the morgue."