An Analysis of Market Demand for Web Programming Languages (October 2012)

What about the wages/salaries + the rest of the labor supply side? Comparing the raw quantity of job postings (labor demand) across cities doesn't have much value. The suggestion you received in your last post about collecting this data over time was the best one you've gotten. Building on that, you need some way to proxy for the number of relevant job seekers in each location (and for each programming language in perfect world) because 10 times more jobs in city A than city B doesn't matter if there are 10 times more potential workers in city A. The other piece that you could think about adding is a way to detect when a job match occurred. Although it's far from perfect, a start would be doing something like inferring from recently removed Craigslist posts that "Hey this post that used to be here is now gone. They must have found a job candidate." Obviously it's a strong assumption since posts can be removed for a number of reasons, including ones that would lead to a false-positive under the assumption I just described. On the other hand, one metric you'd get out of your data if you setup the system this way is the length of time jobs across programming languages and cities remain active (e.g. "Jobs for Python developers in Austin, TX appear to get filled N times faster than jobs for C# developers.") If nothing else, this time-based metric could be used to explain the supply side -- cities that fill jobs for a certain language faster on average may be doing so because there are more potential employees in that area. You could even use Google Trends data to see how trends for searches for "python jobs" or whatever in each city affects the story.

It's something to think about and play around with. I've read published economics research papers that used the "post removed" assumption in the market for used products on Amazon.com -- when a unique URL for a used product would disappear, the authors concluded that to be a sale [at the price it was last observed at].

I see you have 'closure' listed under client side languages, are you referring to Clojure?

In which case it is most definitely server-side, unless you meant Clojurescript?

My experience is much different (and I've looked in many different sections on craigslist).

Python, PHP, Java, and C# were the top. Ruby was almost non-existent.