TheLegend
Megathread Gadfly
There is where context is king. Phoenix is now 5th in population, but only within the city limits. The population of the entire metro is what determines the real value of a 'city''s population, otherwise, Miami wouldn't be on the radar of the leagues since it has ~7% of the population of the South Florida metro within its city limits. Measuring core city's population while ignoring the metro seems more like a counterproductive exercise when it comes to major league sports economics.
Checking the DMAs, Phoenix is 12th for 2017-18, around where it's been for a while. Can't find the MSAs, but Phoenix is unlikely to be that high (5th) since the metro would have to absolutely soar in population to jump up so many positions on the high end.
Per Wiki.... List of metropolitan statistical areas - Wikipedia
Phoenix is ranked 11th by 2017 estimates. But it doesn't specify how many cities outside of Phoenix and Scottsdale are included. Until you go to this page....
Phoenix metropolitan area - Wikipedia
If you want to really dig up every city population defined within the metro area then be my guest. But the overall estimate is pretty close. However.... it is also one of the fastest growing metros in the US as noted by this on the page..
It is also one of the fastest growing major metropolitan areas, gaining nearly 400,000 residents from 2010 to 2015, and more than 1.3 million since 2000. The population of the Phoenix Metropolitan Area increased by 45.3% from 1990 through 2000, compared to the average United States rate of 13.2%, helping to make Arizona the second fastest growing state in the nation in the 1990s (the fastest was Nevada).[4] The 2000 Census reported the population of the metropolitan area to be 3,251,876.