[chrisdbaldwin]

And who is to stop a software company from doing the opposite? If they want lower wages, they could spam a region with fake workers with lower wages.

[patcheudor]

Thus to the original point: self reported data is questionable.

[mfoy_]

It would be neat if the IRS / CRA / national tax body would publish summaries based on people's actual tax returns. Although you don't specify things like industry, and other career specific quirks on your tax returns. (i.e. Ruby on Rails developer vs Dynamics CRM developer)