The figures suggest that the rapidly growing Texas metropolis, known as the Metroplex, passed us about two years ago and now outnumbers us by about 177,000.
You wouldn't know that, though, from the annual Greater Philadelphia Regional Report put out last month by Select Greater Philadelphia, which promotes the region as a place to do business. Although using the new census numbers, Select still listed this area as the nation's fourth biggest.
That's because the group's definition of the region differs from the Census Bureau's, with Select including the Trenton area and excluding Cecil County, Md. Based on those parameters, the region remains a tad more populous than Dallas-Fort Worth.
"We consider Greater Philadelphia to include the 11 counties that we think represent the natural economy of the region," said Nicole Blatcher, Select Greater Philadelphia's director of public relations.
So does ranking a bit lower in population reduce the region's importance nationally?
"We're big enough that we're always going to matter, and we remain part of the nation's largest mega-region," said Steven T. Wray, executive director of the Economy League of Greater Philadelphia. "The question is: What are we doing with what we have? Big isn't everything."
One population category in which the Philadelphia area still can claim fourth place, at least for now, is as a media market.
According to Nielsen Media Research, we trail only New York, Los Angeles and Chicago in total potential viewers within range of our local television stations. By the way, Dallas ranks sixth on that score, Phoenix 13th.
As for the Philadelphia-Phoenix comparison, census estimates out yesterday show Phoenix with nearly 65,000 more residents than Philadelphia as of July 1, 2006.
Past census numbers, newly revised, indicate that Phoenix assumed the head-count lead sometime early in 2005, if you believe the estimates.
The new census report points out that Philadelphia is one of only three cities, along with New York and Chicago, that was in the top 10 a century ago and remains there now - although the city had about 100,000 more residents then than it does today.
Census estimates place Philadelphia's population at 1,448,394 as of a year ago, down nearly 70,000 since the 2000 census and down about 8,000 from mid-2005.
Based on recent experience with the numbers, some city officials are skeptical that the decline has been that big.
In the late 1990s, census estimates had the city losing more than 168,000 people during the decade; the official decline, based on the actual 2000 census count, turned out to be fewer than 70,000.
Phoenix had the largest population increase of all U.S. cities between 2005 and 2006, gaining an estimated 43,000 residents to get to 1,512,986.
In percentage terms, the nation's fastest-growing places (with populations in excess of 100,000) were all suburbs, led by North Las Vegas, Nev., which expanded by 11.9 percent in a single year. Three of the 10 fastest-growing suburbs were in the Dallas area, which helps explain its metropolitan growth.
The census develops its estimates by looking at building permits and other indicators of change.
Contact senior writer Larry Eichel at 215-854-2415 or email@example.com.