Joel Kotkin and Richard Florida are going at it again.

Kotkin this week laid out a future for American cities that favors not the "superstars" with the highest real estate prices, like New York, L.A. and Boston, but rather cities that still offer opportunities for upwardly mobile immigrants and members of the working and middle classes. He offers some damning numbers to help explain "why the largest companies -- with the notable exception of Silicon Valley -- have continued to move toward the more opportunistic cities. New York and its environs, for example, had 140 [Fortune 500] firms in 1960; in 2006 the number had dropped to less than half that, some of those running with only skeleton top management. Houston, in contrast, had only one Fortune 500 company in 1960; today it is home to over 20." And those companies that remain based in New York increasingly only base top staff and a skeleton crew there.

The same trend emerges when looking at job growth and immigration patterns: "'Between 1990 and 2006, job growth in Las Vegas averaged over 6% annually; Phoenix and Riverside well over 3%; Houston, Atlanta, Dallas and Charlotte right around 2%. New York City, L.A., Boston, Chicago and San Francisco all remained well less than 1%… Since 2000, Riverside, Phoenix, Charlotte, Las Vegas and Dallas all have been among the big net gainers with such migrants. In contrast New York, Boston, L.A. and even the Bay Area, a big winner in the 1990s, appear to have become among the highest net losers."

Kotkin has made this case before, arguing that the high cost of real estate is depressing L.A.'s economy, and making the case for a bust.

In the Journal dispatch, Kotkin calls out the absurdity of lefties backing mayors like Michael Bloomberg, who's openly called New York "a luxury city":

Elite city boosters like academic Richard Florida consider any return to a traditional "back to basics" agenda as reflective of "neocon anti-urbanism."

This is something of an oddity, where the fashionable "left" defines successful urbanism by its ability to lure the superaffluent, the hypereducated and the avant garde -- or what Dr. Florida calls "the greatest number of the most skilled people." One wonders what true progressives like Harry Truman or Fiorella La Guardia would think of such an approach.

Florida responds on his blog by asking "what else [besides a neocon anti-urbanist] do you call someone who goes out of their way to trash America's greastest cities, consistently lashes out against its best mayors, and dismisses a good chunk of urban America as 'yuppies, sophistos, trendoids and gays.'" He also takes a passing swipe at this blog, labeling us Kotkin's "Manhattan Institute running-buddies" and claiming that the only mayors we like are "Fiorello LaGuardia and Rudy Giuliani."

We can only assume, then, that Florida also considers the Brookings Institute to be a made up of right-wing city haters, given their recent report on the disproportionate impact of outsourcing on the same metropolitan economies that Florida touts. (There's more on outsourcing and white collar jobs in particular in this report from Berkley's Fisher Center for Real Estate & Urban Economcs showing that "places with high shares of the labor force employed in at-risk white-collar occupations tend to have larger populations, a more highly educated workforce, and higher earnings. Despite these advantages, between 2001 and 2003 these places had slower employment growth, in both at-risk occupations and overall, and to some extent lower wage growth than places with fewer at-risk jobs.")

Or perhaps Florida thinks the rise of the $25 million pied a terre in Manhattan will trickle down and benefit the creatives. In fact, the sharp growth of absentee apartment owners in New York, combined with sluggish job growth, portends a city where new jobs will be created one $1,000 meal at a time.