So now that Phoenix has passed (or is on the brink of passing) Philadekphia to become America's fifth-most populous city, how long until they catch up to Houston for #4?
During the 1990s, Phoenix grew by 34 percent, or 340,000 residents, and its metropolitan area, which includes the city, grew by a phenomenal 45 percent -- adding more than 1 million people to the 2.3 million it had in 1990.
In the same decade, Houston grew by 15 percent in the city and 25 percent in its metro area, adding 260,000 and 950,000 residents respectively.
Turbo-charged Phoenix has a current estimated metro population of 3.2 million to Houston's 5.2 million. If the growth rates since 1990 continue -- and they almost certainly won't -- Phoenix will surpass Houston in both city and metro area population between the 2020 and 2030 censuses, with both metro areas having a population of about 9 million when the graph lines cross.
But that's just playing with numbers. A city must add a larger number of people every year to maintain the same rate of growth, and there aren't enough people anywhere for that to continue indefinitely.
Tim Hogan, director of the Center for Business Research at Arizona State University, said state officials there predict metro Phoenix will actually grow by 2025 to about 5.2 million -- where the Houston area is now. Texas State Demographer Steve Murdock projects metro Houston will reach 5.5 million in 2010 and 6.4 million in 2020.
Is there another threat to worry about?
Realistically, Atlanta may offer Houston a more immediate challenge in the growth game than Phoenix. Metropolitan Atlanta grew by 1.2 million people, or nearly 40 percent, in the 1990s, partly because several more counties were added to its metro area. However, such redefining reflects genuine suburban growth.
Murdock said Houston and Atlanta are "basically the same cities for all intents and purposes. Both have been growing very rapidly, both are in strong growth areas, and I'd hate to make the call as to which is likely to be greater in 20 years."