Joel Kotkin

"This is the city," ran the famous introduction to the popular crime drama Dragnet. "Los Angeles, Calif. I work here." Of course, unlike Det. Sgt. Joe Friday, who spoke those words every episode, I am not a cop, but Los Angeles has been my home for over 35 years.

To Sgt. Friday, L.A. was a place full of opportunities to solve crimes, but for me Los Angeles has been an ideal barometer for the city of the future. For the better part of the last century, Los Angeles has been, as one architect once put it, "the original in the Xerox machine." It largely invented the blueprint of the modern American city: the car-oriented suburban way of life, the multi-polar metropolis around a largely unremarkable downtown, the sprawling jumble of ethnic and cultural enclaves of a Latin- and Asian-flavored mestizo society.

The BP oil spill disaster likely spells the slowing down, or even curtailing, of offshore oil drilling for the foreseeable future. You can take California, Florida and much of the east coast off the energy-drilling map for years, perhaps decades.

But if the oil, gas and coal industries are widely detested on the coasts, people in Bismarck, N.D., have little incentive to join an anti-energy jihad. Like other interior energy centers, people in this small Missouri river city of over 100,000 see their rising oil-, gas- and coal-based economy as the key to a far more lucrative future.

Watford, England, sits at the end of a spur on the London tube's Metropolitan line, a somewhat dreary city of some 80,000 rising amid the pleasant green Hertfordshire countryside. Although not utterly destitute like parts of south or east London, its shabby High Street reflects a now-diminished British dream of class mobility. It also stands as a potential warning to the U.S., where working-class, blue-collar white Americans have been among the biggest losers in the country's deep, persistent recession.

A Study on Upward Mobility, written for the Legatum Institute, London, UK

Since the beginnings of civilization, cities have been the crucibles of progress both for societies and individuals. A great city, wrote Rene Descartes in the 17th Century, represented “an inventory of the possible”, a place where people could create their own futures and lift up their families.

In the 21st Century – the first in which the majority of people will live in cities – this unique link between urbanism and upward mobility will become ever more critical. Cities have become much larger. In 1900 London was the world’s largest urban center with seven million people. Today there are three dozen cities with larger populations.

The awful oil spill in the Gulf--as well as the recent coal mine disaster in West Virginia--has added spring to the step of America's hugely influential environmental lobby. After years of hand-wringing over global warming (aka climate change), the greens now have an issue that will play to legitimate public concerns for weeks and months ahead.

This is as it should be. Strong support for environmental regulation--starting particularly under our original "green president," Richard Nixon--has been based on the protection of public health and safety, as well as the preservation of America's wild spaces.

You can sing about sea to shining sea or amber waves of grain, but it's immigration that provides America's basic rhythm. Nothing distinguishes the American experience from that of other nations more than the mass migration of people from elsewhere to here. We are truly a nation of immigrants: Close to 90% of the population--excluding Native Americans and those who were forced here in shackles--moved here out of their own volition.

Do cities have a future? Pessimists point to industrial-era holdovers like Detroit and Cleveland. Urban boosters point to dense, expensive cities like New York, Boston and San Francisco. Yet if you want to see successful 21st-century urbanism, hop on down to Houston and the Lone Star State.

You won't be alone: Last year Houston added 141,000 residents, more than any region in the U.S. save the city's similarly sprawling rival, Dallas-Fort Worth. Over the past decade Houston's population has grown by 24%--five times the rate of San Francisco, Boston and New York. In that time it has attracted 244,000 new residents from other parts of the U.S., while older cities experienced high rates of out-migration.

For much of the last quarter century, European pundits, particularly in France, have been promoting the notion that the old continent sat on the verge of a grand resurgence. The events of the past month—culminating in a trillion dollar rescue of the Euro—should, at least, put that dodgy notion to rest.

Arizona's recent passage of what is widely perceived as a harsh anti-immigrant bill reflects a growing tendency--in both political parties--to focus on the here and now, as opposed to the future. The effort to largely target Latino illegal aliens during a sharp recession may well gain votes among an angry, alienated majority population, but it could have unforeseen negative consequences over time.

Over the next four decades, American governments will oversee a much larger and far more diverse population. As we gain upward of 100 million people, America will inevitably become a more complex, crowded and competitive place, but it will continue to remain highly dependent on its people's innovative and entrepreneurial spirit.