Even creativity has become a prized international commodity in the new global economy. That's the premise of a book by public policy expert Richard Florida, author of The Flight of the Creative Class: The New Global Competition for Talent (HarperCollins). The book explores how that competition is changing cities around the world, and what the trend means for America's economic future.

Richard Florida attracted widespread attention with his 2002 bestseller, The Rise of the Creative Class. Today's most influential American cities, he wrote, are those that attract the most creative people, whether in the arts, science, technology or business.

But since that book appeared, the George Mason University professor has come to believe that America's most dynamic cities are no longer competing just with one another, but with other magnets for talent and originality around the world. "It's not that any one country, or any one city is going to emerge as globally dominant," Mr. Florida says. "It's that many cities and many countries are going to play a role in this, and that the real key to globalization isn't how many cars or trucks or Coca Colas or MacDonald's hamburgers you trade. It isn't the flows of financial capital from London and Zurich and New York and Tokyo. They're important, but it's the flows of people that are critical. And that competition for people is heating up in a powerful way."

Richard Florida says The Flight of the Creative Class was inspired by a trip to Wellington, New Zealand. He was invited to tour the new digital film studio of Peter Jackson, the award-winning director of The Lord of the Rings trilogy. "What amazed me as I walked through," he recalls, "was that there were about 200 people there from all over the world -- from Europe, France, Germany, people from throughout Asia, and quite a few Americans -- who were not just film people but leading software developers and digital animators. You think about the areas where America has had an edge, and you would say, if anything, Hollywood and filmmaking has been our biggest edge. And I said to myself, if Peter Jackson could do this in Wellington, what else could be happening all over the world?"

What is happening, says Richard Florida, is that cities around the world -- from Melbourne, Australia to Stockholm, Sweden to Vancouver, Canada -- are transforming themselves into global centers for fresh ideas and dynamic new enterprises. At the same time, Mr. Florida worries that one of the traditional mainstays of American inventiveness -- a steady flow of immigrants -- could be endangered. "We wouldn't have Hot Mail, Yahoo, Google, Ebay, Sun Microsystems," he maintains, "if it weren't for foreign immigrants who came here to build those companies, to go to graduate school here, to study here and ultimately to build great enterprises."

Ram Iyengar is part of the current generation of young people who came to America to study. Raised in Bombay, he recently earned a graduate degree in electrical engineering at George Mason University, in suburban Washington, D.C. He is now doing an internship in another Washington suburb. But he is considering going back to India to work -- if not now, then in 3 or 4 years.

"The job prospects out there are pretty amazing these days," he explains. "Basically all these companies are discovering the potential in India, and it's one of the leading powers in Asia right now. The pay packets are great, and you live a more peaceful life in terms of family and culture."

Job creativity is important to Ram Iyengar. "I like new ideas and I like change a lot," he explains. "If they promote creativity, they probably are looking at new frontiers." He says that many of his fellow students from India and China are also considering jobs back in their native countries after graduation.

Not only are promising young immigrants heading for growing opportunities elsewhere in the world, but many are finding it harder to come to the United States, thanks to tightened immigration restrictions. Richard Florida writes in his book that the number of student visas issued by the United States dropped by 8% in 2003, and by 20% in 2002.

"Every immigration official lives in fear that they're going to let in the next terrorist," he says. "But we can't keep out the great entrepreneurial talent that fueled this country. My fear is that we've gotten so concerned with keeping our borders secure that at the same time as other countries compete aggressively for this talent, maybe the United States is taking it for granted."

Besides creating a welcoming atmosphere for talented immigrants, Richard Florida believes the United States should invest more money in research and arts projects. He would like to see greater emphasis on the creative potential of all kinds of jobs -- from moviemaking and computer technology to landscaping and hairdressing. And he calls for renewed efforts to make American cities both livable and affordable.

"I think our cities are really a snapshot of America in that they've been open, creative places where talented people have always migrated," says Mr. Florida. "Whether it's New York City in the 19th century, or Austin or Seattle in the 21st century, America has always been the place where people could reinvent themselves."

Richard Florida ends his book calling for even more daring change. Rather than competing for creative talent, he believes nations around the world should cooperate in that quest. Just as they hold conferences and form commissions on social and economic issues, they should join forces to nurture creativity and encourage its flow across borders. Fostering this new creative age, he writes, requires nothing short of a change in worldview.