Update: Hello HackerNews readers. One thing that I discussed but probably didn't emphasize enough is that this data show the correlation between listed skills and offered wages---you absolutely cannot infer a causal relationship (my cheeky title notwithstanding). Unless I get to create and run a massive skills training program experiment, it's going to be hard to get at causality. But I can do something about the offered/earned distinction. If you don't want to miss my follow-on blog post where I explore the relationship between skills and actual earned wages from actual projects, follow me on twitter.
oDesk recently introduced a controlled, centralized vocabulary of about 1,400 skills for buyers and contractors to use when posting jobs and creating profiles. The primary motivation for the change was to make it easier for buyers and sellers to find each other: without a standardized vocabulary, would-be traders can fail to match simply because they use different terms for the same skill.
A side effect of this transition is that high quality data on the relationships between skills and wages are now available. I recently built a dataset of contractors' hourly wages by skill: for each skill, I identified all contractors listing that skill on their profiles and averaged their offered hourly wages. Although contractors are free to offer any hourly wage they like, in my experience, wages offered closely map to actual earnings. However, to reduce the influence of outliers, I restricted the sample to contractors offering between 50 cents and 100 dollars per hour. I also only included skills for which there were 30 or more observations.
In the bar chart below (made using the very cool googleVis package for R), I plotted the top 50 skills, ordered by average hourly wage (here is a "live" version with mouse-over). The top of the list is dominated by high-end consulting areas (e.g., patents and venture capital consulting) or hot newer technologies (e.g., redis and Amazon RDS). The programming language that commands the highest wage is Clojure, which is a rather esoteric skill: it's a lisp dialect that compiles to the Java Virtual Machine (JVM). Perhaps this is the market reflecting Paul Graham's "Python Paradox":
"if a company chooses to write its software in a comparatively esoteric language, they'll be able to hire better programmers, because they'll attract only those who cared enough to learn it. And for programmers the paradox is even more pronounced: the language to learn, if you want to get a good job, is a language that people don't learn merely to get a job."
At the time Graham wrote this, Python was a far less mainstream language, probably analogous to how Clojure is regarded today. It's an interesting pattern, and although they'd cut up my economist membership card if I made a causal claim between knowing Clojure and being able to command hire wages, I'm intrigued by the idea of using online labor markets as a bellwether to help guide human capital choices.