[jbdeboer]

I'd be interested to know how they are collecting their data. Rent prices are very hard track, short of asking tenants how much they pay.

You can monitor Craigslist, but then you are tracking rental advertisements instead of what tenants are actually paying.

[sliverstorm]

If you want to account for actual pay vs. advertised, you could probably model it to some order of effectiveness by applying a decay function of price vs. age of listing. This operates on the assumption that bargain rentals are on the market briefly, while overpriced rentals languish on the market.

[dimitar]

I would get the data from the same authority that is tracking inflation - rent is included in the basket. In the USA I think the Bureau of Labor Statistics does the 'official' data collection.

Rent prices are pretty uniform - there isn't that much differentiation between properties of the same class (# of bedrooms and location, are what mostly matters; tenants don't make choices based on the type of furniture); so prices are relatively uniform - you don't have to ask a lot of people get those prices.

This is of course confirmed each time someone tries to create yet another index - if you use the same basket and weights, only rarely there are any differences in recorded prices.

[bitcrusher]

Completely anecdotal, but their rental prices for Redwood City are in line with what I pay. The median prices they list for other cities seem to be in line with what I'm seeing looking at different places to live as well.