Last summer, the Census Bureau admitted that Boston’s population is growing (though not as much as the city claims it is). This week, the Arizona Republic reported on signs that Phoenix — long the über-example of explosive population growth in the Sun Belt — may be shrinking:

City records show declining trends in several key areas. Among them: 
• Foreclosure numbers have skyrocketed, meaning fewer city homes are occupied.
• Water hookups are down, suggesting the same.
• Some aspects of trash collection have ebbed because fewer people are buying things that produce waste.
• Crime has declined across the city while police are getting fewer calls for services, a possible indicator of fewer people.
• Sales-tax revenues are likely to drop for the second year in a row, with this year’s collections off almost 8 percent from last year.

There are hundreds of reader comments below the Arizona Republic, many of them trying to attribute any population loss to reasons other than a bad economy. (Some hope that there are fewer illegal immigrants in the city, as if that would be the upside of mass foreclosures, disappearing jobs, etc.) Whatever the reasons, it would be quite a reversal of fortune if Boston’s population is truly growing faster than Phoenix’s for the first time in …. ever?