This is an interesting way of seeing rental housing rents (national scale). And there's a lot that you can glean from a mapping like this. But it's also interesting in that what you are seeing here is a visualization of some 11 million Craigslist rental housing listings (taken from this study). The authors refer to it as a "nontraditional source of volunteered geographic information", and they argue that it's probably more granular and real-time than what is typically available when it comes to rental housing. That sounds right to me.

Yesterday the Globe and Mail published an article titled, “Weakening rental picture latest condo market worry." At first glance, this title seems worrisome. Particularly since Toronto’s condo rental market was supposed to be so robust, with vacancy rates hovering around historic lows.

But as I read the article, I was reminded, once again, about how opaque the real estate marketplace is. To make this prediction, the research group quoted in the article mined craigslist postings. Granted, craigslist is probably the largest source for condo rental listings (even more so than MLS), but I don’t think it necessarily makes it a reliable source.

Craigslist is a messy marketplace. You have expired listings; brokers posting listings in the owner section; brokers posting fake listings for the purpose of lead generation; and so on. It seems to me that there could be a huge margin of error if you tried to rely on this data. So I’m not so sure I would put a lot of weight on a supposed 1.6% rental rate decline.

But what does worry me is how imperfect the real estate marketplace is. It’s incredibly hard to get good data and I think that this is bad for everybody involved in real estate. But network effects are a hard thing to overcome, which is why a messy and ugly marketplace such as craigslist can remain so dominant.