Thanks for making my point for me! The chart really misleads re: the difference between languages. Do we even know if Clojure wages are statistically different from, say, Scala rates?

Other problems:

1. As hinted above, what are the standard deviations? Do we even know if Clojure is statistically different from HAML? Do Clojure rates exhibit higher variation than HAML?

2. $4 difference between pattern recognition v. machine learning, where pattern recognition is, effectively, a subset of ML? We see this with legal services v. contract drafting, and (arguably) info architecture v. interaction design (less overlap with these, to be sure).

Also, while John gets credit for joking about causality, I'd be very concerned about sampling bias if he uses oDesk data to examine human capital decisions.