Ok, to the first point, how do you determine the population of a city on craigslist? For example metro Atlanta has around 5 million people I think, while the actual city is ~600k. And some locations split out, such as LA and Orange County. I think the number of posts is both a good determination of population and usage rates. I'll agree though that it's not perfect, but I'm not sure there's an easy way to determine a "housing metric" for a craigslist city. It's hard to know the size of the surrounding area that uses the service.
As to the second point, the channels may differ, but a city that's affluent and embraces technology should see an proportionate increase on both categories, housing and erotic services. And LA has a great climate for "hollering at cars", while Boston should probably have the higher rate due to weather.
I'm certainly not going to argue that this analysis is anywhere near perfect, but I think you'd agree that Boston at 4% and LA at 24% is probably not just a matter of people moving more frequently.
As to the second point, the channels may differ, but a city that's affluent and embraces technology should see an proportionate increase on both categories, housing and erotic services. And LA has a great climate for "hollering at cars", while Boston should probably have the higher rate due to weather.
I'm certainly not going to argue that this analysis is anywhere near perfect, but I think you'd agree that Boston at 4% and LA at 24% is probably not just a matter of people moving more frequently.