Cities are complicated. And we have spoken before about how it can sometimes feel like they never really reach homeostasis. In extreme cases, it might seem like they're either decaying and losing people, or they're too successful.

I was reminded of this again this morning while reading an article about how Rome's historic city center is being overrun with Airbnbs and tourists, and how it is pushing out the locals. It has, arguably, become too successful as a tourist destination.

Of course, this problem isn't unique to Rome. Venice has the same thing going on, though probably to a greater extent. And Amsterdam is currently working to attract more highbrow tourists and to move their red light district out of the city center.

But the question I have is: What's the right amount of tourism? If 25,000 listings is too many for Rome, what's the right number? And do cities ever really achieve homeostasis, where, you know, things feel just right? Here's an excerpt from the above article that describes what parts of Rome were like before the tourism boom:

Ms. Rapaccini remembers when Monti was a quiet, authentic haven for arty types and locals. She and her late partner, the film director Mario Monicelli, who received six Oscar nominations, moved to Monti in 1988. The area was unfashionable, dirty and full of prostitutes, but beautiful in its gritty way, “like a little village” even though it was in the heart of a big, bustling city, she recalls. The apartments were cheap and the area began to attract film types, journalists and artisans – none of them rich – who mixed easily with local workers and shop owners.

It's a romantic description of what sounds like a pretty gritty area. Unfashionable, dirty, and full of prostitutes is apparently better than full of annoying American tourists. And perhaps it is. But then what was the area like before it was unfashionable, dirty, and full of prostitutes? Was that also better?

I have no idea. But cities are constantly changing and evolving, and they were doing it long before any of us arrived, especially in the case of an ancient city like Rome. Maybe that's what makes it so difficult to hang onto that exact moment in time when everything was just right.

Chart: Globe and Mail