I’m doing some research about the software development market, and I just wanted to share what I am seeing. I’ve been mostly using the Bureau of Labor Statistics (BLS) data sets. They do a home-survey and collect employment and wage data. I would trust these more than self-initiated surveys that would over-represent those that are interested in publishing their salary. Generally, though, I have found these to be consistent with other reports.
To get data broken down by employment, use the Occupational Employment Statistics datasets. To get all software developers, you need to do “Multiple occupations”, so choose one of those reports (probably the geographical area one). I also suggest that you choose “Metropolitan area” because that makes more sense for commute distance, then choose your geographical area.
On the screen where you choose occupations, you want to either choose (151130) which is a summary position OR all of the OTHER 15113x choices (so, 151131-9) that are there. The codes shown depend on your region and what was reported. Those are the choices if you are looking for programmers — if you want DB admins, network admins or something else, then choose appropriately, realizing that codes that end in 0 are summaries.
Another caveat: Self-employed workers are their own category and aren’t broken down further.
According to this, as of May 2012, the Springfield, MA area had 1,350 software developers, with a median annual salary somewhere in the low $70k area. Boston metro has about 50,000 developers and pays more like $100k or so. NYC has 100,000 developers and is also at around $100k median salary. SF (the city, not the valley) is at around 50,000 developers and a median salary a little less than $110k. Silicon Valley (I picked San Jose-Sunnyvale-Santa Clara for this) has almost 60,000 developers making a median salary of $122k. For more complex analysis, you need to download the Occupational Employment Data directly.